Fasten your seat belts: Flying the Oracle Development Cloud Service (2 – Safety)

In this second part of the series we take a look at the safety features on board of our aircraft, named Oracle Developer Could Service.
As in a real aircraft we don’t see all safety features available, as some are hard to show without blacking most of the screen. We cover how the Developer Cloud looks for a new member of a project. Remember that a project in the cloud is not the same as a project in JDeveloper. For more info on this refer to Part 1 – Boarding.

We start with an administrative task of creating a new member for our Identity Domain in the Oracle Developer Cloud Service. This is necessary as only members to the Identity Domain can be members of a project in the Developer Cloud. The Identity Domain is the sandbox which holds all available (or licensed) cloud services. In our installation it contains the services we saw in the first part of the series.

Logged in as an administrator of the identity domain we can add a new user

Add a new member

Add a new member


Clicking on one of the marked links will open a couple of dialogs to fill in the new users data

In the first image we fill in the basic user data like name and e-mail address and the roles the user is assigned to. The e-mail address is significant as the new member gets a nice mail with credentials he/she must use to verify the e-mail address and finish the account building by changing the initial system assigned password.
The possible roles a user can be assigned to can be seen on the left. We only assign the new member the ‘Java Developer’ the role ‘Developers Service User Role’. This is sufficient to work with the Oracle Developer Cloud Service as part of a development team. The other roles allow a user access more administrative tasks and the other parts of the Oracle Development Cloud Service (DB, storage…).
Once the dialog is filled out an e-mail is send to the new member as well as to the manager of the user if this field is filled.
New member e-mail

New member e-mail


When the new member follows the link in the e-mail and logs in the first time he has to change her/his password. This isn’t just changing the password but you also have to answer three questions which are used if you forget you password and need to reset it later. You should note down the answers carefully! The next step is to configure the user interface language and timezone.

Finally you get transferred to the landing page showing all available services from all identity domains the e-mail address is or was registered to.
As I used the e-mail address before to get a trial account the landing page shows multiple identity domains. The one we are using in this post is marked with a red border. You can user the drop down to select to only show one identity domain which makes it less confusing.

Clicking on the Oracle Developer Cloud Service you are transferred to the ‘Welcome Page’ (last image of the gallery). At the moment you can only create a new project, but don’t see any available project. The reason for this is that the new member is not attached to an existing project. This has to be done by an ‘owner’ of the project. Only after this a member can access the project.
To add the new member to an existing project, we log into the Oracle Development Could Service as an owner of the project and add the new member to the project.

Administrator adds new member

Administrator adds new member


The next time the user updates the ‘Welcome Page’ or logs in again he’ll see the project.

Clicking on the project shows the project’s home page with the project’s timeline and information about the git and maven repositories.
Project's landing page

Project’s landing page


Now the new member can access the git repository information by clicking the menu button
Copy git repository address

Copy git repository address


With this information the member can clone the repository using JDeveloper 12.1.3

The member can now work locally with the project and make changes needed or assigned to him/her.

This concludes the 2nd part about safety and setting up members in the Oracle Developer Cloud Service.

In the next part we will introduce how to work with projects and how to setup projects for continuous integration (CI).

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Export to Excel enhancements in JDeveloper 11.1.1.9.0 and JDeveloper 12.1.3

In the current JDeveloper version 11.1.1.9.0 and 12.1.3 the af:exportCollectionActionListener got enhanced by options to filter the data to export.

Enhanced options of exportCollectionListener

Enhanced options of exportCollectionListener


The option this blog talks about is the one marked, the FilterMethod. The ducumentation for 12.12 Exporting Data from Table, Tree, or Tree Table does not reveal too much about how to use this FilterMethod.
The sample we build in this blog entry shows how the FilterMethod can be used to filter the data to be exported to excel.
In older version of JDev you hadto use a trick to filter the data which was downloaded from a table see Validate Data before Export via af:exportCollectionActionListener or af:fileDownloadActionListener. The new property of the af:exportCollectionActionListener allows to filter the data without using the trick.
The sample just load the employees table from the HR DB schema and shows it in a table on the screen. In the toolbar we add a button which has the af:exportCollectionActionListener attached.
Running application

Running application


Below is the page code of the toolbar holdign the export button:

                            <f:facet name="toolbar">
                                <af:toolbar id="t2">
                                    <af:button text="Export to Excel" id="b1">
                                        <af:exportCollectionActionListener type="excelHTML" exportedId="t1" filename="emp.xsl" title="Export"
                                                                           filterMethod="#{ExportToExcelBean.exportCollectionFilter}"/>
                                    </af:button>
                                </af:toolbar>

The filterMethod of the af:exportCollectionActionListener points to a bean method exportCollectionFilter in a request scoped bean ExportToExcelBean. The method gets called for each cell of the table which gets exported.

    /**
     * This method gets called for each cell which is to be exported.
     * It can be used to filter data to be exported. In this case salary values > 6000 are not exported
     * @param uIComponent component of the cess which gets to be exported
     * @param exportContext context of the exported data (holds e.g. file name, character set...)
     * @param formatHandler format to be exported
     * @return true if cell value is exported, false if not
     */
    public Boolean exportCollectionFilter(UIComponent uIComponent, ExportContext exportContext, FormatHandler formatHandler) {
        if (exportContext.isFirstInRow()) {
            count++;
            _logger.info("Start a new Row " + count);
        }
        _logger.info("Export Collection UIComponent: " + uIComponent.getId());
        if (uIComponent instanceof RichOutputText) {
            RichOutputText rot = (RichOutputText) uIComponent;
            Object val = rot.getValue();
            String headerText = "";
            UIComponent component = rot.getParent();
            if (component instanceof RichColumn) {
                RichColumn col = (RichColumn) component;
                headerText = col.getHeaderText();
            }
            StringBuilder sb = new StringBuilder();
            sb.append("Name: ");
            sb.append(headerText);
            sb.append(" Value: ");
            sb.append(val);
            _logger.info(sb.toString());
            // check if the salary is greater than 6000
            if ("Salary".equals(headerText)) {
                if (((BigDecimal) val).intValue() > 6000) {
                    // if yes return false so that the value isn't exported
                    _logger.info("Skip Vals > 6000");
                    return false;
                }
            }
        }

        return true;
    }

The method gets the uiComponent which represents the current cell to be exported, the ExportContext and the FormatHandler for the export. The ExportContext hold information about the filename, title, the used character set and status information about the row and cells currently exported. The status can be used to find out is a new row just starts to be exported ro is a cell is part of a span of cells. In the sample we use this information to print a log message for each row exported.
The FormatHandler is used to generate the document to be exported and the data in it. I did not find a way to use my own handler and there is no documentation about how to use another handler, so we leaf this as is for the moment.
In the sample method we like to filter the employee data in a way, that salaries greater than 6000 are not exported to the resulting file. As the method is called for each cell, the first thing to find out is which cell currently used. In lines 15-29 we use the current UIComponent to find out which column we are in. In lines 31-37 we check the salary column. In case the salary value is greater than 6000 we return false as this will trigger that the cell value is not exported. If the salary is below or equal to 6000 we return true and the cell value is exported.
Below we see the result we get if we export the table without the filterMethod set:

Exported table without filter

Exported table without filter


and the result with the filter method set:
Exported table with filter

Exported table with filter

You can download the sample application which was build using JDeveloper 12.1.3 and the HR DB schema from GitHub.

dvt:treemap showing node detail in popup

This post describes how to implement an dvt:treemap which shows a af:popup when the user clicks on a detail node in the map.
The documentation of the dvt:treemap component tell us that the dvt:treemapnode supports the af:showPopupBehaviortag and reacts on the ‘click’ and ‘mouseHover’ events.
This is part of the solution and allows us to begin implementing the use case. We add an af:showPopupBehavior to the nodes we want to show detail information for.

After creating a default Fusion Web Application which uses the HR DB schema, we begin with creating the data model for the model project. For this small sample the departments and employees tables will be sufficient.


The views are named according to their usage to make it easier to understand the model. This is all we need for the model.

Let’s start with the UI which only consist of a single page. The page has a header part and a center part. In the center area we build the treemap by dragging the Departments from the data controls onto the page and dropping it as treemap. After that, in the dialog we specify the first level of the map to be the departmentId (which shows the department name as the label) and the for the second level we choose the employeeId (which shows the last name of the employee as label) from the employees. The whole process is shown in the gallery below.


The resulting treemap is very basic in it’s features, e.g. there is no legend as you see later.
In the next step we create an af:popup to show the nodes detail information. This process is outlined in the next gallery. We drag the popup component onto the page below the af:treemap component

One thing to take note of are the properties of the popup. First we set the content delivery to ‘lazyUncached’, which makes sure that the data is loaded every time the popup is opened. Otherwise we’ll see only the data from the first time the popup has been opened. Second change is to set the launcherVar to ‘source’. This is the variable name we later use to access the node data. Third change is to set the event context to ‘launcher’. This means that events delivered by the popup and its descendents are delivered in the context of the launch source.

The treemap for example, when an event is delivered ‘in context’ then the data for the node clicked is made ‘current’ before the event listener is called, so if getRowData() is called on the collectionModel in the event listener it will return the data of the node that triggered the event. This is exactly what we need.

Finally we add a popupFetchListener to the popup which we use to get the data from the current node to a variable in the bindings. In the sample this variable ‘nodeInfo’ is defined in the variable iterator of the page and an attribute binding ‘nodeInfo1’ is added. More info on this can be found here.


The code below shows the popupFetchListener:

package de.hahn.blog.treemappopup.view.beans;

import javax.el.ELContext;
import javax.el.ExpressionFactory;

import javax.faces.application.Application;
import javax.faces.context.FacesContext;

import oracle.adf.model.BindingContext;
import oracle.adf.share.logging.ADFLogger;
import oracle.adf.view.rich.event.PopupFetchEvent;

import oracle.binding.AttributeBinding;
import oracle.binding.BindingContainer;


/**
 * Treemap handler bean
 * @author Timo Hahn
 */
public class TreemapBean {
    private static ADFLogger logger = ADFLogger.createADFLogger(TreemapBean.class);

    public TreemapBean() {
    }

    /**
     * listen to popup fetch.
     * @param popupFetchEvent event triggerd the fetch
     */
    public void fetchListener(PopupFetchEvent popupFetchEvent) {
        // retrieve node information 
        String lastName = (String) getValueFromExpression("#{source.currentRowData.lastName}");
        Integer id = (Integer) getValueFromExpression("#{source.currentRowData.EmployeeId}");
        //build info string
        String res = lastName + " id: " + id;
        logger.info("Information: " + res);
        // get the binding container
        BindingContainer bindings = BindingContext.getCurrent().getCurrentBindingsEntry();

        // get an ADF attributevalue from the ADF page definitions
        AttributeBinding attr = (AttributeBinding) bindings.getControlBinding("nodeInfo1");
        //set the value to it
        attr.setInputValue(res);
    }

    // get a value as object from an expression
    private Object getValueFromExpression(String name) {
        FacesContext facesCtx = FacesContext.getCurrentInstance();
        Application app = facesCtx.getApplication();
        ExpressionFactory elFactory = app.getExpressionFactory();
        ELContext elContext = facesCtx.getELContext();
        Object obj = elFactory.createValueExpression(elContext, name, Object.class).getValue(elContext);
        return obj;
    }
}

Finally we have to design the popup to show the node info from the attribute binding ‘nodeInfo1’. The popup uses a dialog with an af:outputText like

Show the node info in the popup

Show the node info in the popup


and set an af:showPopupBehavior to the node showing the employees

Running the finished application brings up the treemap, not pretty but enough to see this use case working. If we click on an employee node we see the popup with the last name of the employee and the employee id, the primary key of the selected row in the employees iterator.

You can download the sample application which was build using JDeveloper 12.1.3 and the HR DB schema from GitHub.

Pitfalls when using libraries of newer version than shipped with JDeveloper or WebLogic Server

A question on JDeveloper & ADF OTN forum cought my attention. A user wanted to use a method of the Apache Commons-IO library named FileUtils.getTempDiretory() but got an error when he tried to use code completion or when he tried to compile the code. The problem was that the compiler (or code completion) did not pick up the right java class from the library even as it was installed in the project a library.
As the original code used belongs to one of my samples I was interested in finding a reason for this behavior as I could see no obvious reason for this behavior.

An inspection of a provided test case quickly revealed the problem and a solution was found too. This blog is about the problem and the solution to it. Lets start with building a test case:


The test case had a model project which used a couple of libraries which we add too to make this sample as close as possible to the test case.
 Model Project Properties

Model Project Properties


There is no code whatsoever used in the model project just the libraries are defined!

To make use of the FileUtils.getTempDiretory() method we have to first download the Apache Commons-IO in a version higher then 2.0. The current version is 2.4 which you get from the given link. Once you unzip the zip (or tar.gz) to a directory of your choice we create a new library for JDeveloper (Tools->Manage Libraries…)

We add This new library to the view controller project


Next is to create a java bean where we try to use the FileUtils.getTempDiretory() method

Here we see the problem mentioned in the OTN question. The FileUtils.getTempDiretory() does not show up at all. The JavaDoc of the Apache Commons-IO 2.4 package shows that the method is available since version 2.0
JavaDoc of FileUtils Class

JavaDoc of FileUtils Class


If we try to compile the code we get an compilation error as seen in the last image.

What is the problem?
Well, it looks like there is another version of the Apache Commons-IO library already loaded in the classpath which gets loaded first. Once a library or class is loaded, another version of the same class will not overwrite the existing one.
First thing we can try is to move the new commons-io library to the top of the list of libraries.
In the test case presented here, this doesn’t work. We still get the same error. So there are libraries loaded before the view controller project libraries come to play.
Remember we added some libraries to the model project even as there is no code in the project at all?
Because the view controller project has dependency defined to the model project when we create an Fusion Web Application by default, libraries of the model project are loaded before the view controller projects.
We have can solve the problem in multiple ways:
1. remove the dependency to the model project. This is not recommended as it would mean that we have to build the model project ourselves if we have to change something in the model and want to run the application.
2. find the library which loads the FindUtils class and see if we can remove it (not all libraries are needed).
3. add the new Apache Commons-IO library to the model project and move it up front. This should load the newer version of the FindUtils class before any other.

Solution 1 isn’t really one. Solution 2 is possible and I’ll blog about it later. For this blog we use solution 3.

Solution
All we have to do is to add the Apache Commons-IO 2.4 library to the model project and move to the top of the list.

Model Project Properties with Commons-IO

Model Project Properties with Commons-IO


If we now rebuild the workspace we see that to error is gone
No Compilation Error

No Compilation Error


The code completion still shows the method red underlined. This is a bug in JDeveloper which doesn’t pick up the right library. Anyway, the compiler will use the right library and we can compile the application.

Now we add another method to the FileBean which returns the path to the temporary directory. This we use in a page index.jsf to show it on the ui.

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE html>
<f:view xmlns:f="http://java.sun.com/jsf/core" xmlns:af="http://xmlns.oracle.com/adf/faces/rich">
  <af:document title="index.jsf" id="d1">
    <af:form id="f1">
      <af:panelGridLayout id="pgl1">
        <af:gridRow height="50px" id="gr2">
          <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc1">
            <!-- Header -->
            <af:outputText value="Preferred Package Test" id="ot1" inlineStyle="font-size:x-large;"/>
          </af:gridCell>
        </af:gridRow>
        <af:gridRow height="100%" id="gr1">
          <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc2">
            <!-- Content -->
            <af:outputText value="Tempdir path = #{FileBean.tempDir}" id="ot2"/>
          </af:gridCell>
        </af:gridRow>
      </af:panelGridLayout>
    </af:form>
  </af:document>
</f:view>

When we run the application we get an exception

    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)
Caused by: java.lang.NoSuchMethodError: org.apache.commons.io.FileUtils.getTempDirectoryPath()Ljava/lang/String;
    at de.hahn.blog.preferredpackages.view.beans.FileBean.getTempDir(FileBean.java:16)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)

Why’s that?
The application compiled without an error and we still get a NoSuchMethodError. The reason for this is that when we start the WebLogic Server the older version of the Apache Commons-IO jar is loaded first, blocking loading of the newer version we need to get to the FileUtils.getTempDirectoryPath() method.
To allow the server to load our newer version of the jar we need to change a descriptor named weblogic-application.xml which is specific for WebLogic Server. For other servers there exist other descriptors allowing the same.
In this descriptor we add a preferred package for the org.apache.commons.io package. Open the weblogic-appliaction.xml descriptor and select the ‘Class Loading…’ node.

Application Descriptors: weblogic-application.xml

Application Descriptors: weblogic-application.xml


Here we enter the package name org.apache.commons.io to the ‘Application Preferred Libraries’ section.

to get this result in the source view of the descriptor:

    <prefer-application-packages>
        <package-name>org.apache.commons.io</package-name>
    </prefer-application-packages>

After restarting the application the index.jsf page show up OK

Running Test Page

Running Test Page

You can download the sample application which was build using JDeveloper 12.1.3 from GitHub.

Initialize an execute af:quickQuery default criteria on page load

Recently a question on the OTN JDeveloper & ADF Space caught my interest. The question was how to initialize an af:quickQuery component with a parameter passed to a task flow on load of a page.
At first I thought that this would be a simple case of setting a property (InitialQueryOverwritten=true) as mentioned by Frank Nimphius in his article How-to query af:quickQuery on page load ?, but after a short test it turned out, that this setting only executes the query but can’t be used to initialize the criteria.

This blog is about a solution to this problem. The question can be divided into two smaller problems to solve. The first is to pass a parameter to a bounded task flow and use the passed parameter in the bounded task flow. The second problem is to initialize a default query attribute of a af:quickQuery component and execute the query.

Let’s have a look at the running application.

Start Page

Start Page


On the start page the user can enter a parameter, which is used as input parameter in the second page, which holds a region (as bounded task flow) with the quick query component. Clicking on the ‘Go Query’ button passes the entered parameter to a pageFlowScope variable. and navigates to the second page.
Start Page Page with initialized af:quickQuery

Start Page Page with initialized af:quickQuery


As we see, the passed parameter is visible in the quick query component and the table shows the corresponding data in the table.

The first problem mentioned isn’t really one as the solution the well documented. So passing a parameter from an af:inputText to a bounded task flow will only showed briefly here. The button on the start page uses a af:setPropertyListener to set the parameter to a pageFlowScope variable. On the second page the parameter is passed as input parameter to the bounded task flow which assembles the af:quickQuery.


The images above showing the navigation between the two pages and the region (QuickQuery.jsf) which holds the af:quickQuery.

First Try
The first method I tried to initialize the af:quickQuery was to overwrite the QueryListener of the af:quickQuery component to set the parameter to the default search attribute. The already mentioned property InitialQueryOverwritten=true would then execute the query with the parameter set. This should show the right result in the table. As it turned out, if the property InitialQueryOverwritten is set to true, the QueryListener is not called on load of the page. No change to set the parameter which is passed to the bounded task flow.

Second Try
For the next try I used a method activity in the bounded task flow and tried to set the parameter from this method. This will not work as the component is not present when the method is called as default activity in the task flow. You can set the parameter to the view object and filter the data after it, however, the overwritten property InitialQueryOverwritten then executed the default query again, this time without the parameter. If you set the property to false, you see the data, but the parameter is not set in the af:inputText component.

Final Try: Working solution
The working solution uses a trick which is kind of lazy initializing the component. For this we bind a property of the component to a bean and overwrite the getter method for the property. In the getter we check a private variable of the bean if the component has been called already or not. In case the getter has already been called we just return the value for the property. In case the getter method is called the first time we initialize the component before returning the value of the property.

Let’s look at the af:quickQuery in the region:

                        <af:quickQuery label="Search" searchDesc="#{viewScope.QuickQueryBean.dummy}" id="qryId1"
                                       value="#{bindings.ImplicitViewCriteriaQuery.quickQueryDescriptor}"
                                       model="#{bindings.ImplicitViewCriteriaQuery.queryModel}"
                                       queryListener="#{bindings.ImplicitViewCriteriaQuery.processQuery}" binding="#{viewScope.QuickQueryBean.quickQuery}">
                            <f:facet name="end">
                                <af:commandLink text="Advanced" rendered="false" id="cl1"/>
                            </f:facet>
                        </af:quickQuery>

Two things to note are
1. the component is bound to the viewScope bean QuickQueryBean
2. the searchDesc property is bound to the same QuickQueryBean bean
The component is bound to the bean as a convenience to get the query descriptor easily in the initialization method. To make this save we use a ComponentReference to store the component.

    private ComponentReference quickQuery;
    /**
     * setter for component to ComponentReference
     * @param quickQuery the component
     */
    public void setQuickQuery(RichQuickQuery quickQuery) {
        this.quickQuery = ComponentReference.newUIComponentReference(quickQuery);
    }

    /**
     * getter for the component from the component reference
     * @return
     */
    public RichQuickQuery getQuickQuery() {
        if (quickQuery != null) {
            return (RichQuickQuery) quickQuery.getComponent();
        }
        return null;
    }

For more information about this technique see Rules and Best Practices for JSF Component Binding in ADF

The lazy initialization is done by binding the searchDesc property to the QuickQueryBean. The trick is that the component has to call the getter for this property to get it’s value. In the getter in the bean

    /**
     * getter for a string value names dummy in EL
     * @return value of the dummy property
     */
    public String getDummy() {
        if (needInit) {
            needInit = false;
            initQuickQuery();
        }
        return "Search";
    }

we check a local variable ‘needInit’ which is set to true when the bean is created each time the page gets loaded. As the bean is in viewScope it guarantees that the bean is created each time the page is loaded and stays active until the page is visible.
The real work is done in the initQuickQuery() method:

    /**
     * Initialize the quickQuery component if a parameter tpCityName is found in the pageFlowScope. Once this is done, the pageFlowScope
     * variable tpCityName is set to null or removed.
     */
    public void initQuickQuery() {
        // get the PageFlowScope Params
        AdfFacesContext adfFacesCtx = AdfFacesContext.getCurrentInstance();
        Map<String, Object> scopePageFlowScopeVar = adfFacesCtx.getPageFlowScope();
        String paramCity = (String) scopePageFlowScopeVar.get("tpCityName");
        if (paramCity != null && !paramCity.isEmpty()) {
            // get query descriptor (the components value property)
            FilterableQueryDescriptor queryDescriptor = (FilterableQueryDescriptor) getQuickQuery().getValue();
            // get the current selected criterion (which should set in the ImplicitViewCriteriaQuery in hte pageDef
            AttributeCriterion attributeCriterion = queryDescriptor.getCurrentCriterion();
            // get the attribute name and check if it'S 'City'
            AttributeDescriptor attribute = attributeCriterion.getAttribute();
            String name = attribute.getName();
            // only set parameter if hte attribute matches the parameter
            if ("City".equalsIgnoreCase(name)) {
                attributeCriterion.setValue(paramCity);
                // remove value to allow new one in component
                scopePageFlowScopeVar.put("tpCityName", null);
                // set the parameter to the attributeCriterion 
                QueryModel model = getQuickQuery().getModel();
                model.setCurrentDescriptor(queryDescriptor);
                // create a queryEvent and invoke it
                QueryEvent qe = new QueryEvent(getQuickQuery(), queryDescriptor);
                invokeMethodExpression("#{bindings.ImplicitViewCriteriaQuery.processQuery}", Object.class, QueryEvent.class, qe);
            }
        }
    }

In this method we check if a parameter named ‘tpCityName’ is present in the pageFlowScope (lines 8-10). If yes the next check is if the current selected criterion the for the selected parameter, in this case the ‘City’ (lines 11-19) . Only if this test is positive the value from the parameter is set to the criterion (line 20), the pageFlowScope variable ‘tpCityName’ is removed and the new criterion is set back to the query model (lines 21-25). Finally to execute the af:quickQuery we create a new QueryEvent and invoke it via an EL (lines 26 -28).
The solution does not need to set the InitialQueryOverwritten property to true to run. The query is fired after setting the attribute via the QueryEvent. Here is an image of the af:quickQuery binding

Definition of the ImpliciteViewCriteriaQuery

Definition of the ImpliciteViewCriteriaQuery

The sample needs the HR DB schema. You can download the code for the sample, which was build using JDeveloper 12.1.3, from GitHub. Please note that if you run the sample in your environment, that you have to change the DB connection to the HR DB schema according to your environment.

How-to filter ADF bound tables by date range (JDeveloper 12.1.x)

Based on an older article from Frank Nimphius How-to filter ADF bound tables by date range JDeveloper 11.1.1.4 I got a interesting question on the OTN JDeveloper & ADF forum why the solution provided in the article does not work in JDev 12c.

The solution from Frank’s article is designed for JDev 11.1.1.4.0. Today’s version of JDev is 12.1.3 where the solution does not seem to work. Migrating the source of the article and running it under JDev 12.1.3 indeed shows, that filtering the employees records for a date range does not work at all. Setting dates into the filter and hitting enter to activate the filter does not filter the data in the table.
The reason for this was easily found by debugging the code. Set a breakpoint into the query listener which is setup in the table

<af:table value="#{bindings.allEmployees.collectionModel}" var="row" 
  rows="#{bindings.allEmployees.rangeSize}"
  emptyText="#{bindings.allEmployees.viewable ? 'No data to display.' : 'Access Denied.'}"
  fetchSize="#{bindings.allEmployees.rangeSize}" rowBandingInterval="0"
  filterModel="#{bindings.allEmployeesQuery.queryDescriptor}" filterVisible="true" 
  varStatus="vs" selectedRowKeys="#{bindings.allEmployees.collectionModel.selectedRow}"
  selectionListener="#{bindings.allEmployees.collectionModel.makeCurrent}" 
  rowSelection="single" id="t1" styleClass="AFStretchWidth"  partialTriggers="::cb1"
  queryListener="#{EmployeeQueryBean.onEmployeeQuery}">

As you can see it’s pointing to a bean method ‘onEmplyoeeQuery’. A look into this method reveals that the method FilterableQueryDescriptor.getFilterCriteria() has been deprecated.

        FilterableQueryDescriptor fqd = (FilterableQueryDescriptor) queryEvent.getDescriptor();
        Map map = fqd.getFilterCriteria();

Instead of the deprecated method you should use the method FilterableQueryDescriptor.getFilterConjunctionCriterion() which now holds the map of parameters.

        FilterableQueryDescriptor fqd = (FilterableQueryDescriptor) queryEvent.getDescriptor();
        ConjunctionCriterion cc = fqd.getFilterConjunctionCriterion();
        Map<String, Criterion> criterionMap = cc.getCriterionMap();

When you set a breakpoint in this method and step through the code you see that the values entered into the filter fields in the UI are not visible in the map as Frank describes in his article.

Criterion Map and old FilterCriteria Map

Criterion Map and old FilterCriteria Map


As you can see there are no map entries for the made up variables ‘HireStartRange’ and ‘HireEndRange’. This is the reason the filter by date range does not work. There are simply not dates to filter the rows.

I’m not sure if this is a bug or a change in behavior which was made for a reason. Anyway, you can’t just simply add values to the map anymore.

The solution to fix the problem is simple. As you can’t store additional values in the criterion map, you have to store the values entered by the user somewhere else. A valid storage area is the variables iterator each pagedef holds.
In one of my other blogs Creating Variables and Attribute Bindings to Store Values Temporarily in the PageDef I showed how to add temporary variables in this iterator.

Create two new variables inside the variable iterator of type oracle.jbo.domain.Date, name them ‘startDate’ and ‘endDate’. Then create attribute bindings for them.
The final touch is to wire the new variables up in the HireDate filter for start range and end range:

                                    <af:column sortProperty="HireDate" filterable="true" sortable="true"
                                               headerText="#{bindings.allEmployees.hints.HireDate.label}" id="c1" width="277">
                                        <f:facet name="filter">
                                            <af:panelGroupLayout id="pgl2" layout="horizontal">
                                                <af:panelLabelAndMessage label="From: " id="plam1">
                                                    <af:inputDate id="id2" value="#{bindings.startDate1.inputValue}" clientComponent="false">
                                                        <af:convertDateTime pattern="#{bindings.allEmployees.hints.HireDate.format}"/>
                                                        <f:validator binding="#{bindings.HireDate.validator}"/>
                                                    </af:inputDate>
                                                </af:panelLabelAndMessage>
                                                <af:spacer width="5" height="5" id="s1"/>
                                                <af:panelLabelAndMessage label="To:" id="plam2">
                                                    <af:inputDate id="id3" value="#{bindings.endDate1.inputValue}" required="false" clientComponent="false">
                                                        <f:validator binding="#{bindings.HireDate.validator}"/>
                                                        <af:convertDateTime pattern="#{bindings.allEmployees.hints.HireDate.format}"/>
                                                    </af:inputDate>
                                                </af:panelLabelAndMessage>
                                            </af:panelGroupLayout>
                                        </f:facet>
                                        <af:inputDate value="#{row.bindings.HireDate.inputValue}" label="#{bindings.allEmployees.hints.HireDate.label}"
                                                      required="#{bindings.allEmployees.hints.HireDate.mandatory}"
                                                      shortDesc="#{bindings.allEmployees.hints.HireDate.tooltip}" id="id1" styleClass="AFStretchWidth">
                                            <f:validator binding="#{row.bindings.HireDate.validator}"/>
                                            <af:convertDateTime pattern="#{bindings.allEmployees.hints.HireDate.format}"/>
                                        </af:inputDate>
                                    </af:column>

The code above shows the new column for the HireDate and the new storage location for the startDateRange as ‘value=”#{bindings.startDate1.inputValue}”‘ and EndDateRange as ‘value=”#{bindings.endDate1.inputValue}”‘. Next we change the bean method which reads the filter values and calls the query:

    public void onEmployeeQuery(QueryEvent queryEvent) {
        //default EL string created when dragging the table
        //to the JSF page
        //#{bindings.allEmployeesQuery.processQuery}

        BindingContext bctx = BindingContext.getCurrent();
        DCBindingContainer bindings = (DCBindingContainer) bctx.getCurrentBindingsEntry();

        //access the method bindings to set the bind variables on the ViewCriteria
        OperationBinding rangeStartOperationBinding = bindings.getOperationBinding("setHireDateRangeStart");
        OperationBinding rangeEndOperationBinding = bindings.getOperationBinding("setHireDateRangeEnd");

        // get the start date and end date from the temporary valiables
        AttributeBinding attr = (AttributeBinding) bindings.getControlBinding("startDate1");
        oracle.jbo.domain.Date sd = (oracle.jbo.domain.Date) attr.getInputValue();
        attr = (AttributeBinding) bindings.getControlBinding("endDate1");
        oracle.jbo.domain.Date ed = (oracle.jbo.domain.Date) attr.getInputValue();

        //set the start and end date of the range to search
        rangeStartOperationBinding.getParamsMap().put("value", sd);
        rangeEndOperationBinding.getParamsMap().put("value", ed);

        //set bind variable on the business service
        rangeStartOperationBinding.execute();
        rangeEndOperationBinding.execute();

        invokeMethodExpression("#{bindings.allEmployeesQuery.processQuery}", Object.class, QueryEvent.class, queryEvent);
    }

In line 14-17 you see that we read the values from the newly created attribute bindings for the temporary variables. After removing the unnecessary parts of the code, which tried to read the values from the map, the rest of the code remains as is.

Here is an image of the now working filter by date range

Filter Table by Date Range

Filter Table by Date Range

Please note that if you run the sample in your environment, that you have to change the DB connection to the HR DB schema according to your environment. You can download the changed code for the sample from GitHub

Change Application Configuration at Run Time through a Properties File (Part 1)

Often users ask how to change some configuration properties, e.g. a reprot definition file or endpoint of a web service, art runtime of the application. This is not an easy task as such configuration normally is deployed together with the application as part of the ear file. This however can’t be changed easily.

There are different possible solutions, like providing a Mbean which then can be used in the weblogic servers admin console to change values. A sample for this approach can be found e.g. here Creating Mbeans(JMX) in ADF Application and accessing them from jrockit mission control.

In this blog I show a different approach which uses a configuration file which can be changed externally. The values read from the file are properties (key value pairs). If we make changes to the file they are reflected during run time without the need to restart the application. Keep in mind that this approach does not work will on a clustered system as there are multiple servers with multiple file locations which have to change. One way to overcome this is to set the location on e shared file system which can be accessed from all servers.

To implement this use case we first have to think about how we get the path to the configuration file and it’s name to load it during run time.

To get the path the the configuration file we use a context parameter which we define in the web.xml file. The reason for this is that we need to change this parameter depending on the system we deploy the application too. In addition you can’t make predictions like where an administrator likes to put the configuration file.

Context Parameter in web.xml

Context Parameter in web.xml

To load the properties we can use java default Properties class which loads properties from a stream. The bit and bytes can be found in the source of the work space which is available GitHub (see link at the end of the post).

One thing to notice is that this post uses Apache Commons-IO version 2.4. This update make one other change necessary in the weblogic-application.xml file.

  <prefer-application-packages>
    <package-name>org.apache.commons.io</package-name>
  </prefer-application-packages>

This entry allows the application to use the included commons-io jar to be loaded before the already available commons-io jar, of an older version, in WebLogic server 12.1.3.

After setting the parameter let’s write a sample page where we show some of the properties on the page, then change the configuration reset the properties and see the changes on the page.
For the implementation we use an application scope bean. The reason is that the configuration parameter should be available application wide. There is no need to keep this info per session. If you read the configuration file for every parameter you can use a request scope bean.

In a live system I would not recommend using this approach (reading the configuration file every time) because it produces a bottleneck reading the file over and over again. Instead I would call a method periodically or as the result of a user action like button click.

OK, let’s create a configuration file in the WEB-INF folder or if you like in any other folder. Once the file is created we copy it into a temporary folder on the system (/tmp on mine) and read it from there.


Now we need an application scope bean

The bean has a getProperties method which checks if the proprieties are already read or if not read the context parameter from web.xml to read the file from the given position.

    /**
     * This method savely get the properties from a file if the file can be read, otherwise it return an empty properties object
     * @return Properties object read from file of empty properties object if hte file was empty or could not be found
     */
    public Properties getProperties() {
        if (properties == null) {
            FileInputStream fileInputStream = null;
            try {
                // read context parameter
                String initParameter = FacesContext.getCurrentInstance().getExternalContext().getInitParameter(PROPERTYFILE_PARAMETER);
                logger.info("Read properties from " + initParameter);
                // try to read the file
                File file = FileUtils.getFile(initParameter);
                fileInputStream = FileUtils.openInputStream(file);
                properties = new Properties();
                properties.load(fileInputStream);
                logger.info(properties.size() + " properties successfully read.");
            } catch (IOException ioe) {
                logger.warning("Error: Property file could not be read!", ioe);
                properties = new Properties();
            } finally {
                if (fileInputStream != null)
                    try {
                        fileInputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
            }
        }
        return properties;
    }

    /**
     * Reset the read properties so that the next try to read a property ready the file again
     */
    public void readPropertiesAgain() {
        logger.info("Reset properties!");
        properties = null;
    }

    /**
     * Method to return the version information of the configuration file.
     * this information is compiled from the keys PROPERY_NAME and PROPERTY_VERSION
     * @return version information read from the file
     */
    public String getPropertyVersionInfo() {
        String property = getProperty(PROPERTY_NAME);
        String property_2 = getProperty(PROPERTY_VERSION);
        String res = "Unkown";
        if (property != null && property_2 != null) {
            res = property + " " + property_2;
        }
        logger.info("Properyinfo: " + res);

        return res;
    }

The second method is used to reset the local storage of the properties, so that the next time a property is read the whole file will be read again. The third method is used to get the version information of the configuration file which is build as the concatenation of two properties.

On a page we add a button to reset the properties in the application scoped bean. After this the configuration file will be read again.

<af:button text="Read Configuration again" id="b1"
 actionListener="#{ReadPropertyFileBean.rereadActionListener}"
 partialSubmit="true"/>

Finally we add an outputText component to the page which uses an EL to read the PropertyVersionInfo from the application scoped bean ‘ReadPropertyFileBean’

<af:outputText id="ot6" inlineStyle="font-size:small;" 
 value="#{ReadPropertyFileBean.propertyVersionInfo}"
 partialTriggers="b1"/>

When we run the application we see the inital screen like

Initial index.jsf

Initial index.jsf


we change the configuration file
Changed Configuration File

Changed Configuration File


and reset the properties via a click on the button
Changed index.jsf

Changed index.jsf

This concludes part 1. In the final 2nd part we see how to change the fixed path set as context parameter in web.xml during deployment. This allows us to deliver a properties file together with the application but let the administrator decide where to put it on the server.

The work space for this sample can be downloaded from GitHub BlogReadConfigFile Release 1.0 or get the zipped workspace of this release 1.0
The sample is build using JDeveloper 12.1.3 and uses the HR DB schema.

The Git Experience (Part 4)

In this part of the ‘Git Experience’ series we are looking at GitFlow. GitFlow is a branching model which helps you and your company to structure your work in a way which is understandable and has proven it’s value in many projects. I don’t want to copy all information given in the link about GitFolw but only use the image from the blog post:

GitFlow Model

GitFlow Model

What we see in this image is a timeline of development with releases, hot fixes, development and feature branches and how they work together. We like to use this model to structure the work of the development. The development needs to set up the software for releases which are delivered to the customer or an internal server. Then there is the need to supply hot fixes if a release version has a major bug. Nevertheless development has to develop for the next release, probably breaking the task into smaller pieces we call features. To keep this features in our repository as well we use feature branches which are merged back to the development branch once they are ready and tested.

The development branch is the grapevine for the development. Feature branches as well as release branches are started from the development branch. Once a release is ready the release branch is merged and tagged on the master branch and merged to the development branch.

IMPORTANT: you never work directly on the master branch!

In the last part ‘The Git Experience (Part 3)’ we started a new repository on GitHub which we use in this part to introduce GitFlow on it. There are several ways to do this. You can use the command line and execute the git commands from there. Or you use shell scripts to put multiple git commands as a unit of work together and call the script to e.g. start a new feature branch. The last and least complicated way is to use a tool which already has set up the scripts for you and gives you a nice GUI to work with.

We follow the last suggested way and use a tool with graphical user interface. As JDeveloper does not support the usage of GitFlow with a GUI we use an external tool like ‘SmartGit’ or ‘Source Tree’ which both come with a graphical user interface supporting GitFlow. For the remainder of this blog we use SmartGit as it’s available for Windows and Linux operating systems. It’s free for non commercial use.

Once we started SmartGit we can add our local repository to be shown in SmartGit. Don’t be confused this with cloning a repository. Cloning fetches a remote repository from a remote server and creates a local copy of it on your pc. As we already have the local repository on out machines we just add the local repository.

For those of you how did not create the repository in the last part you can clone it from my GitHub server repository using ‘https://github.com/tompeez/BlogReadConfigFile.git&#8217; as url for the clone command.

After this SmartGit looks the same as the last image after adding the repository. You now can play with the SmartGit UI (or any other too you are using). One thing I like to bring to attention is the ‘Log’ button. Clicking this button opens a new window which shows the timeline of all commits.

Right now we only see two nodes which were created during creation of the repository.

Let the fun begin: Introduce GitFlow to the project

Now that the local repository is up in the tool of choise, lets introduce GitFlow to it. For this we click the GitFlow Button, select the ‘Full’ radio button and leave the rest of the options as is.

This will add another branch to the repository named ‘develop’

Repository after GitFlow Introduction

Repository after GitFlow Introduction

However, this  new branch is not the current branch as the ‘master’ branch is still marked current. Please also note the different color of the GitFlow button. In this shape it starts a HotFix as the master branch is the current branch and all hot fixes are started from the master branch, or better a release tag on the master branch.

GitFlow Button: Start HotFix

GitFlow Button: Start HotFix

We change this by double clicking the develop branch to get

and see the GitFlow button changes to a different default action, ‘Start Feature’ as we are now working on the develop branch. Before we start our first feature we take a look at the GitHub remote repository:

GitHub Timeline

GitHub Timeline

As we see the remote repository still only have one branch ‘master’. This is a lesson we have to learn fast. Everything we do, we do only locally. The remote repository doesn’t know about our work until we tell about it or push our changes to the remote repository.

Let’s push the ‘develop’ branch to the remote repository by clicking the Push button

Last thing to do is to do some house keeping on the GitHub side. Here we set the ‘develop’ Branch as ‘default’ branch.

Now we are ready to start our first feature. Remember that the feature branch is only created on the local repository and not automatically pushed to the remote GitHub repository. If you like the feature branch to be visible in the remote repository you have to push it there after creating it.

We create a feature ‘Feature_1’ (you should choose a more meaningful name!):

As we see the new branch is the current working branch. We now make some changes e.g. adding a header above the table and then look at the changes in the SmartGit and GitHub UI.

We add a panelGroupLayout to the top facet of the panelStretchLayout to add a header telling us what we see and another text telling that this was added with ‘Feature-1’. This is just for the time we are playing with the GitFlow features. We later can safely remove this second text.

As we see, all tools showing the same changed files. The interesting thing is that we see a changed index.java file. The only change we made was to add something to the index.jsf file!

Well, this second change was not intended but is the result of a setting in JDeveloper which adds a property to a backing bean for every component we add to the index.jsf file. Before we remove this nonsense setting let’s save the changes to our repository and look at the different tools:

In the first image we see an interesting info: ‘Outgoing (1)’. This means that SmartGit knows that this branch isn’t connected to the remote repository and can’t seen there. This isn’t really necessary as Git is a distributed version control system, but other users can’t get to this branch if the PC holding it isn’t available (due to network restrictions or because it’s offline).

After this the new branch is visible and tracked in GitHub. Now we can remove the not needed nor wanted index.java backing bean.

Why is it there in the first place?

If we create a new view in a task flow we have the option to activate the automatic component binding to a backing bean in this dialog

Automatic Component Binding

Automatic Component Binding

Well, it’s either a bug in JDev 12.1.3 or a saved configuration I made to investigate something else which uses automatic component binding. Les’s assume the latter and remove this setting.

Now we have to remove line 76 in the index.jsf file, fix the bindings in index.jsf by replacing them (find: binding=\”#{backingBeanScope.backing_index..*\”), remove the bean from adfc-config.xml and finally remove the index.java file from the project

Now we can compile the source, test the application and then save the changes in the repository. Don’t forget to push the changes to the remote repository!

If you use SmartGit to commit the changes you can commit and push in one command by clicking the ‘Commit & Push’ button in the dialog. The final timeline in SmartGit looks like

SmartGit Timeline

SmartGit Timeline

Time to wrap everything up. We made some changes and now are finished with our feature. We now finish the feature in SmartGit by clicking the GitFlow button and follow the dialog

The second image shows the options we have to finish a feature. Here we can decide to remove the feature branch completely or, as we do, keep it for later. As features are not used by GitFlow to build a release or hot fix on them, there is generally no need to keep them after they are finished and merged back into the development branch.

The final thing to make the circle is to build a release from the current development branch.

We add a release note part to the README.MD file to make the release visible in the file too. Now we commit the change (not shown) and finish the release

In image 2 we can set the options we want to use to finish the release. The one we change from the default is that we like to keep the release branch so that we can see it in the timeline. This is not necessary as you can’t do anything with the branch (beside cherry picking :)). The last image shows the SmartGit timeline where we see all commits and the different branches used. This show look like the GitFlow image we started this blog with.

This finishes part 4 of the blog. The repository (and it’s branches) and be cloned or loaded from GitHub.

The Git Experience (Part 3)

Almost a year ago I posted the second part of my git experience series (JDeveloper 11.1.1.6.0: The Git Experience (Part 2)). In this part I announced a third part which should handle working with remote git repositories.

I totally forgot about this. Only after a question on OTN JDeveloper and ADF forum I looked up the older blogs about git. Since the last post a new JDev version 12.1.3 has arrived so I decided to use this new version to continue the series.

In this part we are talking about setting up a remote repository. As remote git server I use GitHub which allows you to easily set up an account for non commercial use without any cost. Please read the all about the process on the GitHub Help web page.

Before we begin we have to talk about security accessing the remote repository. There are multiple possible connection strategies. The more common are ssh and https. Both are supported by GitHub, https is the recommended.

In this blog I use https to authenticate and work with GitHub, all you need to remember is your GitHub username and it’s password. I tested ssh too but like https better as you don’t have to handle the ssh keys on every pc you use (and I use up to 10 different machines).

I assume you have built yourself an account on GitHub which you can use. If you don’t want to create one yourself you can use the repository of this blog (link available at the end of the blog). Creating a new remote repository yourself can’t be done without an account. For those of you part 4 of the series which will be published in a couple of days will talk about how to do real work with remote repositories and introduce GitFlow as work template.

Let’s start with a typical workflow. We want to implement a new application using JDev 12.1.3 and want to use git as version control system. As the development is done on multiple locations, the repository should be accessible for all team members 24/7. This exclude a repository on a local pc which others might not be able to reach (e.g. if it’d down).

We generate a new ADF Fusion Web Application. I spare the walk through this process. As name of the new application workspace we choose BlogReadConfigFile, every other name you like is OK too.

Once the new application workspace is ready we like to put it under git control. We first do this locally by using the ‘Team->Version Application…’ menu. See the gallery below fro the whole process.

Notice the ‘.git’ folder which holds all information about the git versions of the application on your local pc. The fresh created local repository can be used already to make changes and commit them to the local repository. Other team members can clone the repository from your pc if they have access to it.

As the new workspace is under version control we can and should open a new window in JDev via menu ‘ Window->Team->Version’ to get a view of the version information available in JDev:

Open Version Window

Open Version Window

Expanded Version Window

Expanded Version Window

As you’ll notice all remote nodes in the tree are empty. The local master branch is the current branch we are working on, visible through the green badge. Now we want to make this local repository available to a remote git server GitHub. First problem is that JDev 12.1.3 (and all other version I know of) don’t support creating a remote repository. We can add existing remote repositories by right clicking to the ‘Remotes’ node and ‘add remote…’

Add a Remote Repository

Add a Remote Repository

Add Remote Dialog

Add Remote Dialog

As you see you can only add the URL to the remote repository but can’t create it. So we have to create the remote repository on GitHub first. Read ‘Setup a new Repository’ to find out how to do this. Make sure you make it a public repository and leave the check box to init the repository with a README.md file empty for the moment.

Create Repository in GitHub

Create Repository in GitHub

You can add default ‘.gitignore’ fie and a licence via this dialog too. We use a ‘.gitignore’ file from other JDev projects as the default java one doesn’t know about some of the artifacts used by JDev. After finishing the dialog you get the information from GitHub how to get data into the new repository.

How to add Data

How to add Data

If you decide to use ssh instead of https you can click the button on the left side of the URL and the info switches accordingly.

As we already have our local repository we use the second method ‘…or publish an existing repository from the command line’. For this we open a command shell and open the location of the workspace (‘/data/development/ENTW_12.1.3.0.0/QT/BlogReadConfigFile’ on my machine). Copy the commands from the second option into the command shell. You are asked for your credentials to login into GitHub, after that the local repository is pushed to GitHub.

Command Lines to Push Data to Repository

Command Lines to Push Data to Repository

When we look at the GitHub web page we see the data from the workspace

Finished Remote Repository

Finished Remote Repository

As mentioned at the button of the page we should add a README.md file. This can be done directly on the web page or you can add such a file on your local pc and push it to the repository. I like to do this through the web page as it copies the description from the creation of the repository into the file.

Add README.md

Add README.md

Now if we look at the Versions window in JDev we see that the remote repository is visible in JDev too.

Updated Version Window

Updated Version Window

Dev knows about the changes as they all in the ‘.git’ folder in the workspace. Right now command line git , JDev git and third party tools like SmartGit, SourceTree or mysygit (or Tortoise Git on windows) play well together. You can use them interchangeably.

As we have added the README.md file using the web page, out first action is to refresh the workspace to get the README.md file into our local repository. For this we use the menu ‘Team->Git->Pull…’, work through the wizard and check the file system after the work has finished.

This concludes this part 3 of the series. You can clone the repository from GitHub. Stay tuned for the next part where we introduce GitFlow and start working on the repository.

Handling images/files in ADF (Part 5)

I received a couple of questions regarding the handling of the images directly after upload for the sample application done in part 1-4.

    Part 1 gives an overview of the sample application I’m going to build and how to set it up
    Part 2 shows how to upload a file, store it and download it back to the client
    Part 3 implements two techniques to show the data (image) on the user interface
    Part 4 backport of the sample to JDeveloper 11gR1
    Part 5 implements a technique to show the uploaded file right after upload without the need to commit first

The sample application finished in part 3 (part 4 is a backport to JDev 11gR1 only) has one minor glitch: it doesn’t display an uploaded image directly to the user after uploading it. The user has to commit the data after insert or update of an image before the image becomes visible. Users like to see the newly uploaded image before committing the row. This allows the users to cancel the change or select and upload another image. In this 5th part of the series we implement this.

Before we start to implement let’s talk about how to implement this enhancement. Why isn’t it possible to upload the image data into the blob and then just show the image from the blob via the servlet (see part 3)?
The problem is that the BlobDomain uses a stream to read the data uploaded from the user. This stream can only be read after the BlobDomain is saved, meaning after the commit.

The solution we implement in this part stores the uploaded data (inserted or updated) in a temporary file on the server. Then the server uses the image data from the temporary file to visualize the data. This sounds easy enough, however there is some house keeping to do to make it work.

First we have have to find a place (folder) where we can store the uploaded data until it’s stored in the db or the operation is canceled. Then we need to distinguish which data to show from the servlet (file or blob). Finally we have to clean up the temporary file when we are done.

Lets dive into the implementation. We start from the application at the end of part 3. As the current JDeveloper version is 12.1.3 we do the implementation in this version. The first task is to migrate the old application to 12.1.3. This is done automatically when opening the old work space in JDev 12.1.3 by answering the ‘OK’ to the migration popup. Nothing need to be done here. However, when you download  the work space you’ll notice some clean up I did, like changing the old af:commandButton to the new af:button.

One thing to notice is that the Apache Commons-IO version is updated to 2.4. This update made one other change necessary in the weblogic-application.xml file.

  <prefer-application-packages>
    <package-name>org.apache.commons.io</package-name>
  </prefer-application-packages>

This entry allows the application to use the included commons-io jar to be loaded before the already available commons-io jar, of an older version, in WebLogic server 12.1.3.

Here are the steps we take to implement the tasks:
1) Save the uploaded data to a temporary file as well as to the blob. This is done for convenience. It’S possible to store the data first in the temporary file and only copy it to the BlobDomain when the user commits the changes.
We implement a new java class UploadBlob which holds the BlogDomain and the path to the temporary file. This class also allows to test if a temporary is available.

package de.hahn.blog.uldl.view.types;

import oracle.jbo.domain.BlobDomain;

/**
 * This type class holds the BlogDomain and a path to a temporary file holding the uploaded image data
 */
public class UploadBlob {
    /**
     * Holds the uploaded data
     */
    BlobDomain dataBlob;

    /**
     * Path to the temporary file if availabe
     */
    String tempFile;

    /**
     * C'tor.
     */
    public UploadBlob() {
        super();
        tempFile = null;
        dataBlob = null;
    }

    /**
     * Gets the status of the temporary file
     *
     * @return true if a temporary file is available, false otherwise
     */
    public Boolean getTempFileAvailabe() {
        return (tempFile != null ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * @param inageBlob
     */
    public void setInageBlob(BlobDomain dataBlob) {
        this.dataBlob = dataBlob;
    }

    /**
     * Gets the BlobDomain holding the uploaded data
     * @return
     */
    public BlobDomain getDataBlob() {
        return dataBlob;
    }

    /**
     * Sete the path to the temporary file holding the uploaded data
     * @param tempFile path to the temporary file
     */
    public void setTempFile(String tempFile) {
        this.tempFile = tempFile;
    }

    /**
     * Getter for path to temp file holding the data of the uploaded data
     * @return path to the temporary file holding the uploaded data
     */
    public String getTempFile() {
        return tempFile;
    }
}

2) Use this class in the ImageBean.java class where the uploaded data is read. This happens in the valueChangeListener uploadFileValueChangeEvent(ValueChangeEvent valueChangeEvent).

    /**
     * @param valueChangeEvent
     */
    public void uploadFileValueChangeEvent(ValueChangeEvent valueChangeEvent) {
        // The event give access to an Uploade dFile which contains data about the file and its content
        UploadedFile file = (UploadedFile) valueChangeEvent.getNewValue();
        // Get the original file name
        String fileName = file.getFilename();
        // get the mime type
        String contentType = ContentTypes.get(fileName);
        // get the current roew from the ImagesView2Iterator via the binding
        DCBindingContainer lBindingContainer = (DCBindingContainer) BindingContext.getCurrent().getCurrentBindingsEntry();
        DCIteratorBinding lBinding = lBindingContainer.findIteratorBinding("ImagesView2Iterator");
        Row newRow = lBinding.getCurrentRow();
        // set the file name
        newRow.setAttribute("ImageName", fileName);
        // create the BlobDomain and set it into the row
        UploadBlob blob = createBlobDomain(file, Boolean.TRUE);
        newRow.setAttribute("ImageData", blob.getDataBlob());
        // set the mime type
        newRow.setAttribute("ContentType", contentType);
        String tmp = (blob.getTempFileAvailabe() ? blob.getTempFile() : null);
        setTemporaryFileVar(tmp);
        UIComponent ui = (UIComponent) valueChangeEvent.getSource();
        // PPR refresh a jsf component
        ui = ui.getParent();
        AdfFacesContext.getCurrentInstance().addPartialTarget(ui);

    }

Instead of reading the data into the BlobDomain a changed method createBlobDomain is called (line 18). the method now returns an instance of the new class UploadBlob. Below is the code of the new method:

    private UploadBlob createBlobDomain(UploadedFile file, Boolean createTempFile) {
        // init the internal variables
        InputStream in = null;
        OutputStream outTmp = null;
        UploadBlob blobDomain = null;
        OutputStream out = null;
        File tempfile = null;
        logger.info("Starting to create UploadBlog from data...");
        try {
            logger.info("... create BlobDomain...");
            blobDomain = new UploadBlob();
            // Get the input stream representing the data from the client
            in = file.getInputStream();
            // if a temporary file should be created , we do this first as we can't get
            // data data back from the blob until we commit the row. in the next step we
            // write the upload data to a temp file and then copy it into the blob
            if (createTempFile) {
                logger.info("... Creating temporary file...");
                File tempdir = FileUtils.getTempDirectory();
                String ext = FilenameUtils.getExtension(file.getFilename());
                if (!ext.isEmpty()) {
                    ext = "." + ext;
                }
                logger.info("... set extension to " + ext + "...");
                tempfile = File.createTempFile("upl", ext, tempdir);
                logger.info("... " + tempfile.getAbsolutePath() + "...");
                // set path to temporary file
                blobDomain.setTempFile(tempfile.getAbsolutePath());
                FileOutputStream fileOutputStream = FileUtils.openOutputStream(tempfile);
                logger.info("... copy data to temporary file...");
                IOUtils.copy(in, fileOutputStream);
                in = FileUtils.openInputStream(tempfile);
                logger.info("... set inputstream for blog to temporary file...");
            }
            // create the BlobDomain datatype to store the data in the db
            blobDomain.setInageBlob(new BlobDomain());
            // get the outputStream for hte BlobDomain
            out = blobDomain.getDataBlob().getBinaryOutputStream();
            // copy the input stream into the output stream
            logger.info("... copy data to BlobDomain ...");
            /*
             * IOUtils is a class from the Apache Commons IO Package (http://www.apache.org/)
             * Here version 2.0.1 is used
             * please download it directly from http://projects.apache.org/projects/commons_io.html
             */
            IOUtils.copy(in, out);
            logger.info("... Finished OK");
        } catch (Exception e) {
            logger.severe("Error!", e);
            if (tempfile != null) {
                // delete temp file on exception but don'T throw one if there is another exception
                logger.info("Deleted temporary file " + tempfile.getAbsolutePath());
                FileUtils.deleteQuietly(tempfile);
            }
        }
        // return the filled BlobDomain
        return blobDomain;
    }

Depending on the new boolean parameter passed to the method a temporary file is created and the uploaded data is first saved to the temporary file. After that the data is copied from the temporary file into the BlobDomain. At this point the path to the temporary file is saved in the new class for later reference. In case of an exception the temporary file is removed.
Finally in line 22 and 23 of the value change listener we check if a temporary file was generated and we set the path to it to a pageDef variable (see Creating Variables and Attribute Bindings to Store Values Temporarily in the PageDef). For this we use the code below.

    /**
     * Set the temporary file name into a page variable for later use
     * @param name
     */
    private void setTemporaryFileVar(String name) {
        // set pathto temporary file to page variable
        BindingContainer bindings = BindingContext.getCurrent().getCurrentBindingsEntry();
        // get an ADF attributevalue from the ADF page definitions
        AttributeBinding attr = (AttributeBinding) bindings.getControlBinding("TemporaryFile1");
        if (attr != null) {
            attr.setInputValue(name);
        }
    }

The variable is used in the af:image component in the editImage.jsff fragment

                   <af:image source="/render_image?id=#{bindings.ImageId.inputValue}&tmp=#{bindings.TemporaryFile1.inputValue}" id="i1"
                              shortDesc="#{bindings.ImageName.hints.tooltip}" inlineStyle="width:200px;" partialTriggers="cb3" visible="true"/>

here the path to the temporary file is passed to the servlet as second parameter ‘tmp’. In lines 24-27 of the value change listener we send a ppr to the parent component of the af:image to show the now uploaded image.

Another thing to do is to cleanup after the user either cancel or commit the changes. This is done in the cancel_action() or the commit_action() in the ImageBean. Here we call the deleteTemporaryFile() method which checks the existence of a temporary file and deletes it.

    /**
     * delete the temporary file if is present
     */
    public void deleteTemporaryFile() {
        String tempfile = getTemporaryFileVar();
        removeTemporaryFile(tempfile);
        setTemporaryFileVar(null);
    }

3) The final part of the implementation is done in the servlet which is used to get the data back to the client. This is simple as we read the second parameter passed to the servlet. If it’s not empty we always read the image data from the temporary file. If the parameter is empty the servlet gets the data by reading the row from the DB and read the data from the blob. Here are the relevant parts from the servlet:

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        StringBuilder sb = new StringBuilder(100);
        String appModuleName = "de.hahn.blog.uldl.model.facade.ULDLAppModule";

        sb.append("ImageServlet ").append(appModuleName);

        try {
            // get parameter from request
            Map paramMap = request.getParameterMap();
            oracle.jbo.domain.Number id = null;
            String tmporaryFilePath = "";
            if (paramMap.containsKey("id")) {
                String[] pVal = (String[]) paramMap.get("id");
                id = new oracle.jbo.domain.Number(pVal[0]);
                sb.append(" id=").append(pVal[0]);
            }
            // check if we find a temporary file name. In this case we allways use this!
            if (paramMap.containsKey("tmp")) {
                String[] pVal = (String[]) paramMap.get("tmp");
                tmporaryFilePath = pVal[0];
                sb.append(" tmp=").append(pVal[0]);
            }

            OutputStream outputStream = response.getOutputStream();
            InputStream inputStream = null;
            BlobDomain image = null;
            String mimeType = null;
            // no temporary file path given, read everything from DB
            if (tmporaryFilePath.isEmpty()) {
                // get method action from pagedef
                BindingContext bindingContext = BindingContext.getCurrent();
                DCBindingContainer amx = bindingContext.findBindingContainer("de_hahn_blog_uldl_view_image_dummyPageDef");
                JUCtrlActionBinding lBinding = (JUCtrlActionBinding) amx.findCtrlBinding("getImageById");
                // set parameter
                lBinding.getParamsMap().put("aId", id);
                // execute method
                lBinding.invoke();
                // get result
                Object obj = lBinding.getResult();
                ImageAccessViewRow imageRow = (ImageAccessViewRow) obj;

                // Check if a row has been found
                if (imageRow != null) {
                    // Get the blob data
                    image = imageRow.getImageData();
                    mimeType = imageRow.getContentType();
                    // if no image data can be found and no temporary file is present then return and do nothing
                    if (image == null) {
                        mLogger.info("No data found !!! (id = " + id + ")");
                        return;
                    }
                    inputStream = image.getInputStream();
                } else {
                    mLogger.warning("No row found to get image from !!! (id = " + id + ")");
                    return;
                }
                sb.append(" ").append(mimeType).append(" ...");
                mLogger.info(sb.toString());
            } else {
                // read everything from temporary file path
                mimeType = ContentTypes.get(tmporaryFilePath);
                File file = FileUtils.getFile(tmporaryFilePath);
                FileInputStream fileInputStream = FileUtils.openInputStream(file);
                inputStream = fileInputStream;
            }

            // Set the content-type. Only images are taken into account
            response.setContentType(mimeType + "; charset=utf8");
            IOUtils.copy(inputStream, outputStream);
            if (tmporaryFilePath.isEmpty()) {
                // cloase the blob to release the recources
                image.closeInputStream();
            }
            inputStream.close();
            // flush the outout stream
            outputStream.flush();
        } catch (Exception e) {
            mLogger.log(Level.WARNING, "Fehler bei der Ausführung: " + e.getMessage(), e);
        } finally {
            mLogger.info("...done!");
        }
    }

The gallery below shows the new work flow.

The work space for part 5 can be downloaded from the ADF EMG Sample side BlogUploadDownload_12.1.3V4.zip.
Or if you are in GIT you can get the work space from GitHub BlogUploadDownload_12.1.3V4