Problems running JDeveloper 12c

In the last couple of weeks, I get more and more reports of problems running JDeveloper 12.2.1.x. (to be exact 12.2.1.1.0, 12.2.1.2.0 and 12.2.1.3.0)

The problems reported are

  • properties editor not working
  • JDeveloper hangs during start
  • showing wireframe instead of page design
  • problems to configure the JDBC connection
  • problems compiling expression on attributes (not 100% verified that this is JDK problem)
  • problems migrating projects created with earlier versions of JDeveloper
  • problems with the groovy script engine
  • deadlocks within JDeveloper when editing multiple java files

to name some. The problems are not ADF related but IDE related. It turned out that they only could be reproduced if the used JDK to run JDeveloper on was newer than JDK 1.8.0_101. All problems are not reproducible when running JDeveloper with JDK 1.8.0_101.

Currently, there is a bug pending (Bug 26766333) with support.oracle.com for some but not all mentioned issues. At the moment of writing this, there is no patch available.

My recommendation is to install JDK 1.8.0_101 and run JDeveloper using this JDK. You can do this by

  1. installing JDK 1.8.0_101 on your machine. The download for this old version is hard to find in the WWW. To make it easier, you can find it on this page: Java SE 8 Archive Downloads
  2. change the product.conf file you’ll find in your .jdeveloper folder inside your home folder. Open the file and set the SetJavaHome property
  3. to be on the safe side, you can recreate the integrated WLS to make it use JDK 1.8.0_101 too. If you know our way in the jungle of script files which are used to start the embedded WLS, you can change those files directly. As there typically are not many changes made on the integrated WLS, I find it easier to delete the integrated WLS and create it again. It’ll pick up the JDK JDeveloper is running on automatically and use it to run the WLS too.

You don’t need to update or change the JDK your standalone server is running on. To my knowledge, the problems are only IDE related, so they don’t affect the running application.

If you find a problem, which is related to using a JDK newer than 1.8.0_101, feel free to leave a comment on this post. I’ll add them to the list for reference.

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JDeveloper: Skin Radio Buttons

In this blog article, I like to share how to use a skin to alter the look of radio buttons in ADF. The use case was a question on the ODC space JDeveloper & ADF which asked about how to provide more space for the radio buttons.

Here is an image of the default and the resulting radio buttons:

As you see, in the first radio group the space between the selectItems is narrower than in the second group.

In my older post about JDeveloper: Advanced Skin Technique I showed how to find out which style to change, so I spare this here.

The image above shows the standard “radiogroup” in Chrome Developer Tools. As you can see the radiogroup consists of “div” elements, each specifying one of the selectItem.

To change the spacing, we add a style class to the skin file like

.mysor af|selectOneRadio::content div {
  padding: 0px 0px 10px 0px;
}

The “.mysor” is the name of the style class which we later use on the page. The magic is done by specifying the base style as af|selectOneRadio::content and from there style each “div” element having the base style as a parent. This way we style the blue marked div in the image above.

One question remains. Why do we use a skin and don’t add the code right into the page?

Well, using a skin is the preferred method. The skin is created once and can be used everywhere in the application. If you need to make changes, you don’t have to search for the pages where the style has been added, but you just change the skin file and you are done.

Download Sample

You can download the sample which is build using JDev 12.2.1.2.0 and uses the HR DB schema from GitHub BlogAdvancedSkin

 

 

JDev: Badge Button

In this article, I describe how to build what I call a ‘Badge Button’. This is a button we know from many mobile applications which shows, e.g., how many new messages have arrived since the last visit.

The image above shows what I have in mind. We see a standard button with a badge indicating the number of new items. The badge can be used to display text as well

The idea behind this came from a question on the ODC JDev & ADF space. When I first read the question I wanted to answer “No, there isn’t such a component in ADF”, but after thinking about it, I decided to build one myself.

The Problem has two parts:

  1. How to build the badge
  2. How to create the component looking like a button with a badge

Solution Part 1

Making the badge turned out to be very easy. Searching the web, you find plenty of solutions for such components using CSS. As you might know, it’s not very straightforward to add a CSS solution to ADF. However, there are ways to do this. In the end, I used the following CSS to generate the badge:

.badge {
 background: radial-gradient( 5px -9px, circle, white 8%, red 26px );
 background: -moz-radial-gradient( 5px -9px, circle, white 8%, red 26px );
 background: -ms-radial-gradient( 5px -9px, circle, white 8%, red 26px );
 background: -o-radial-gradient( 5px -9px, circle, white 8%, red 26px );
 background: -webkit-radial-gradient( 5px -9px, circle, white 8%, red 26px );
 background-color: red;
 border: 2px solid white;
 border-radius: 12px; /* one half of ( (border * 2) + height + padding ) */
 box-shadow: 1px 1px 1px black;
 color: white;
 font: bold 15px/13px Helvetica, Verdana, Tahoma;
 height: 16px;
 padding: 4px 3px 0 3px;
 text-align: center;
 min-width: 14px;
 margin: 0px 0px 20px -10px;
 position: relative;
}

Solution Part 2

ADF uses CSS which is built from skin files. It’s not straightforward to add any other CSS to a component as you don’t see the generated HTML where you need to add the CSS. So adding the CSS class just as style to the button doesn’t work, as you can’t add new properties to ADF components. You will get an error like

To create a badge, you need to create a span or div with the CSS class and some data which is put into the badge like
Selection_474

This can’t be added to an existing component easily. However, ADF has a component which renders as a div tag, the af:outputText. If you add an af:outputText to a page and look at the resulting HTML you get
Selection_475
So, the value of the outputText is just surrounded by a div tag. The problem still is that you can’t add your own property to the ADF component, but we can add the div with the needed style and the data as the value you the af:outputText component. All we have to do, other than to add the div is to set the escape property of the outputText to false. This setting avoids that ADF encodes the value which would transform the ‘<’ into ‘<’, essentially making a string out of the value. The reason for that is to prevent security issues (injection), so be aware of this!

Putting this on a page would look like

And generates

The solution works somehow, if we put an af:button on the page instead of the af:spacer. However, it looks ugly or ‘uncool’ to see the ‘div’ in the af:outputText.

Final Solution

The final solution is to hide the ‘how to build it’ in a declarative component. The use case is a perfect fit for an ADF declarative component. We move the CSS, the button and the outputText in such a component and can use the component in the page to get

The new solution looks clean, as the CSS and odd looking outputText isn’t visible. Here are some images of the running test application.

The input field is used to set the data to be shown on the badge. It can be numbers, text or both. Clicking on the button calls the action listener and the action.

And this is the log output.

Building the Declarative Component

There are many other blogs about how to create a declarative component so I will not do this in detail. However, I like to point out some things you should keep in mind when you create such a declarative component.

To make the component work, it’s not enough to just add a button and the outputText holding the CSS. We have to make properties available for the action and the actionListener of the button. If we don’t do this, all we get is a button, which is looking good but which can’t be used to start a navigation or to call an actionListener. The same is true for other properties of the button inside the declarative component. We have to add a property for the button text at least. If you like to enable/disable the badge button, you have to expose an attribute in the declarative component interface to get the value from the outside, your page See later).

When we build the declarative component, we start by adding another ‘ADF View Controller Project’ to the workspace. Declarative components should be developed in a separate project. They are deployed as adfLibrary jar files. We add a new JSF Declarative Component to the project.

And fill out a dialog with necessary data. This data can be changed later if needed. Here is a sample

Once we click OK, a jspx page with the selected name will be created alongside a meta-data file holding the information about the tag library.

In the JSPX page, we create the layout of the component. We already know how to add the badge, all we need to do is to put an af:button onto the page and add the code to the badge to it. The resulting declarative component looks like

Select the af:componentDef tag and open the property editor. There you can define metadata like attributes and methods you want to pass to the component from the outside.

And the methods to activate the button.

The data you specified in the property editor is added to the af:componentDef tag.

A special case is the partialTrigger property. You can’t set a partialTrigger from the outside to a component used in the declarative component. However, you can surround the declarative component with another component which has a partialTrigger property and use this outer component to send a ppr. In the code above I surrounded the declarative component with an af:panelGroupLayout which listens for ppr send from the af:inputText with the id “it1”. This partial refresh is needed in the sample to refresh the button with a new value entered in the field.

If you need more attribute to control the behavior of the component, you can add them via the property editor. For this simple test case, the attributes and methods are enough.

The sample application and declarative component is build using JDev 11.1.1.9.0 and can be downloaded from GitHub BlogBadgeButton. The sample doesn’t need a DB.

ODC Appreciation Day: Rapid Development Kit(s)

In 2016 Tim Hall had the great idea to introduce the ‘OTN Appreciation Day’ where bloggers should write a short blog about their favorite Oracle feature. This year’s name is ‘ODC Appreciation Day’ as Oracle rebranded the community to Oracle Developer Community.

As last year the question is which was or is the feature you like best?

Currently, there is a clear number one from my point of view:

Rapid Development Kit(s)

The Cloud User Experience Rapid Development Kit is available for a couple of years already, but with version V13 of the RDK we get a new look and feel representing the current SaaS Applications look. The RDK give developers and designers a tool to quickly design and program applications which are looking like Oracle’s SaaS Applications in the cloud.

There are currently two RDKs available, one for ADF (12c) and one for MAF (2.4.1). The design allows consistent design across devices:

Here is an image of a SaaS application build using the new RDK

But wait, an RDK for JET is in the pipeline. The OAUX Team presented the JET RDK before the OOW to selected partners and ACE Directors. It should be available in the near future.

And an image of a JET application build using the new JET RDK:

As you see there is almost no difference. You develop your application in and get the same look and feel regardless of the technology you use.

Finally, to round things up, Oracle provides an RDK for Conversational UI – or actually the first half of the RDK – the part that deals with designing the conversational UI.

Conversational UI for the enterprise adds to and maybe replaces the current Web&Mobile UI – for quick, simple, mini transaction and smart capture.

Conversational interfaces are initially most likely to be used for:

  • quick decisions, approvals, data submission (do)
  • get information (lookup),
  • conversation as starting point for a context-rich navigation to an application or component (go to)
  • provide recommendations and guidance to users (decision making).

The part about the actual implementation will follow with the launch of the Oracle Intelligent Bot Cloud Service.

References:

The Cloud User Experience Rapid Development Kit

Enhancements give OAUX team’s Cloud UX RDKs a jump on fast and innovative solutions

Oracle Intelligent Bots – Oracle Cloud

OAUX Conversational UI RDK

Train Stop Status Handling

A question on the Oracle Developers Community was about how to handle a train stops visited status.

Use Case

The use case behind this was that a train can be used as a workflow visualization. A normal user starts the train, but at one point a manager has to approve something. This approval is one or more stops on the same train. If the manager picks up the workflow he should automatically start with the approval stop. There is no need for him to see the data accumulated in the stops before.

The use case has multiple challenges:

  1. Securing train stops for different user roles
  2. Allow starting the train from any stop
  3. Handling the state of the train stops

The first two challenges are handler by All Aboard, 97. How-to defer train-stop navigation for custom form validation or other developer interaction, and 82. How to programmatically navigate ADF trains.

The missing part is how to handle the train stops ‘visited’ state (see image above). If you start the train directly with ‘Stop 3’ you get this state

UI

To implement this use case, we use a simple UI. It contains an input field, a button and the train which is added to the page as a region.

In the input field names label 1 you can enter the stop where the train should start. If no number is given, the train starts with the first stop. We use this input field to mimic the different starting stop for different users. This is the page when we start the application:

This is the page when we start the final application:

You can navigate between the train stops by using the ‘Back’ and ‘Next’ button, or by clicking the next stop in the train bar. As the stops are set to sequential, you can’t directly click on the 4th stop. You have to go through the stops 1 to 3 first.

Enter a number between 1 and 5 into the input field and tab out of the field will set the parameter for the train task flow and restart the task flow. The navigation is done via a router in the task flow. In the image below the stop number 3 is set as the starting stop for the train

And as you see the stops 1 and 2 are looking like they have visited before.

Implementation

To show how to implement this we start with a simple bounded task flow which builds the train

The start builds a router which we use to navigate to the stop where we want to start the train. The starting stop is passed as parameter to the task flow

In the router, which is marked as default activity, the parameter is used to execute the navigation

The Magic

If you look at the train stop properties in the properties inspector you’ll notice, that there is no property for the visited state

This option is not available in the UI. Oracle has missed or deliberately missed to make this property accessible via the properties. If you dig into the implementation of the train task flow (see the articles provided at the begin of the blog), you’ll see how to access the train and its stops by code:

ViewPortContext currentViewPortCtx = controllerContext.getCurrentViewPort();
TaskFlowContext taskFlowCtx = currentViewPortCtx.getTaskFlowContext();
TaskFlowTrainModel taskFlowTrainModel = taskFlowCtx.getTaskFlowTrainModel();
// get the stop from the map
TaskFlowTrainStopModel currentStop = taskFlowTrainModel.getCurrentStop();

The TaskFlowTrainStopModel doesn’t provide any access to the visited state. If you look at the class definition you’ll notice, that it’s only an interface

which doesn’t provide access to the visited property. Setting a breakpoint in the debugger we can inspect an instance of this interface

and we get the class implementing the interface as:

 oracle.adfinternal.controller.train.TrainStopModel

This class has the visited property we are looking for.

Solution

Now we can implement a method which we call before a train stop gets rendered and which sets the visited property of all previous stops to true.

CAUTION

THIS IN AN INTERNAL CLASS WHICH YOU SHOULD NOT USE!

However, it’s the class we need to get to the property. You have to understand, that the usage of the class has its risks, but that it’s not forbidden. The risk is that Oracle can change or delete the class without notifying you beforehand. So, in later versions, your code might break.

The method checks the task flow parameter if it’s null to set to a number less or equal to 0. In this case, the method returns an empty string. We do this check to avoid that the method does it’s work every time we navigate the train. It should be done only once when the train starts.

If the check finds a positive number, it sets the task flow parameter to zero (line 37).

It then gets the task flow information from the Context (lines 39-43). In line 50 we acquire the current stop before we loop over all previous stops and set their visited property to true (lines 53-59).

The missing part is how to call this method when a train stop is rendered. For this, we use a technique called Lazy Initalizing Beans. The trick is to use a hidden af:outputText and set e.g. the value property of the component to a bean property.

When the page or fragment is rendered, the method getInitStatus() in the bean is called. This is exactly the method shown above. We add this hidden af:outputText to each train stop before the af:train component.

Sample

You can download the sample from GitHub BlogTrainStopStatus. The sample is build using JDev 12.2.1.3 and doesn’t need a DB connection. You can use the same technique in other JDeveloper versions.

Blog Using External REST Servies (Part 1)

Using External REST Services with JDeveloper 12.2.1.2 (Part 1)

In this blog we look how we can use an external REST service with JDev 12.2.1.2. To make things more interesting we don’t use an ADF based REST service and we look how to get nested data into the UI.

For this sample we like to create an application which allows to search for music tracks and show the results in a table or listview. To get the music data we use a REST service and to display the data we use ADF faces application.

In part 1 we create the application and the project for the REST Data Control. Part 2 we will create the UI using the REST Data Control.

Setting up an external REST services

Let’s start be selecting a REST service which is available for public use without the need to get a key first. We use such a service to make it easier for you to run the sample and to look at the code. If we would need a key to use the API, you would need to register yourself with the service before you can run the sample.

There are a couple of such REST services like Spotify, iTunes or MusicBrainz which offer search APIs for music data as public REST service. Spotify we have to eliminate from the list as this service requires an API key since Mai 2017, meaning that it’s not public available without you register yourself before using it. ITunes REST API allows public access and the data structure returned is very simple. The result for a search get you everything in a flat structure. This will make things easy, too easy 🙂

For this sample where we like to show how to work with more complex data structures returned by a REST service. So, the final vote for this blog goes to MusicBrainz (MusicBrainz Rest API).

MusicBrainz

Musicbrainz REST API comes in different versions (V1 and V2). The current version v2 is what we are interested in as V1 is already deprecated. The documentation tell us, that the service is an XML style REST service. However, there is a JSON style REST service available too. This JSON style RSET service is what we use for the sample.

Before we implement the REST service calls we need to find out how to search for the data we like to show. For this a tool like Postman is a great help. Postman allows you to enter calls to REST services in a browser like UI. You can set all kind of headers, e.g. below we see a sample of the Postman UI (in the result a couple of sub structures are folded to show the relevant data). The query searched for recordings named ‘yesterday’ and asked for a result in JSON format:

To learn more about the possible searches refer to Web Service Search.The data structures and their meaning are described in in the MusicBrainz Data Structure.

Use Case

Before we begin implementing something which uses the external REST service we have to think about the use case. We like to implement a music title search using the external MusicBrainz REST service. A user should be able to enter a music title or part of a music title and as a result of the search she/he should get a list of titles, the artist or artists, the album and an id.

Creating a REST Web Service Project

After we looked at the REST Service and the data it returned we have identified the data we need to get from the REST service. The first step is to create a project which communicate with the REST service.

We create a normal Fusion Web Application which will create a ADF model project and a view controller project. If you need a script on how to do this you can look at Writing Reproducible Test Cases: Why and How. The model project we don’t need for this sample. You can delete it or just leave it empty.

For the access to the MusicBrainz data we create a new REST Web Service Project inside the application:

Name it and go through the rest of the wizard

Before we create the web service data control, we need to create a REST Connection from the resource pallete we create a new IDE connection of REST type

Then we later need data returned from the REST service which the wizard uses to produce the data structure. A simple way to get such data is to use e.g. Postman to call the REST service:

Copy the result (all of it!) and save it to a file. Next we create a new Web Service Data Control from the gallery

Select the ‘WebService Data Control (SOAP/REST)’

And fill out the wizard. Select the REST connection created before

In the next image click on the green ‘+’ sign

And change the path to ‘/ws/2/recording’, select JSON as data format and checkmark the GET method to enter ‘recording’ into the field.

In the next screen we need to select ‘Parse from Sample Code’ and copy the content of the file we saved from Postman into the textarea

And finally test the Web Service Data Control

The finish the wizard. Now we can test the data contron by finding the DataControl.dcx file in the project and right click on it. Choose ‘Run’ from the context menu:

In the dialog window right click hte data control and choose ‘Operations’

Fill in the fields and click the execute button

The result should look like

You can copy the return value into an editor to fully see it. If you don’t get the successful result, check the steps against the ones in the blog.

This concludes part 1 of this series. In part 2 we develop the UI for the application using the Web Service Data Control we created in this part. The source of the sample can be downloaded from GitHub. The link to it will be provided with part 2.

JDeveloper: How to setup and use a converter

JDeveloper: How to setup and use a converter

In this post I show how to setup the server side part of a converter and how to use it in an application. Converters can have a client side too and all af:converter do have one. For a nice sample on what you can do with client side converters see ADF: Smart Input Date Client Converter. The big difference is that the client side converter is done on the client side with JavaScript and no server round trip is done for the conversation.

Why are converters needed at all?

Sometimes the data you get from a source like the database table is not in a format you like to show to the user. Common cases are showing strings in special formatting, e.g. social security numbers or phone numbers. You can use converters to show the content of clob and blob columns in the UI too.

The ADF framework provided some converters out of the box:

These can be used without the need to program anything.

What is missing from the out of the box converters is one which can be used to format a string.

One thing to remember that the new format should only be used in the UI to show the data in a specific format. You normally don’t want to store it in this special format.

We create a converter which exchanges each uppercase character ‘B’ in a string with the string “-Z-”. The sample is not very useful, but it shows what can be done with converters.

Use Case

A string can contain any character. However when the string is shown on the UI there should be no ‘B’ visible. Instead of the ‘B’ we should show ‘-Z-’. This should only be done when the string is visible on the UI. When the string is stored in the db or some other place it should be stored with the ‘B’.

Implementation

I used JDev 11.1.1.7.0 for this sample, which is the oldest JDev version I have access to. The steps to create a converter should be almost equal in all versions, but I deliberately choose the oldest JDev I have so that other users with other version should have no problem migrating this sample to their version.

The final sample can be downloaded from GitHub at BlogConverterSample.

Model Project

We start by creating a fresh ADF Web Application. If you want a detailed description on how to do this, you can follow Writing Reproducible Test Cases: Why and How. For the model part I only use one DB table, the EMPLOYEES table. The resulting model project looks like

We don’t need to make any change to the generated project. This model project is only created to show that the converter works on data read from the DB table too.

ViewController Project

For users interested in more details about converters, please read the doc at http://docs.oracle.com/cd/E48682_01/web.1111/b31973/af_validate.htm#BABGIEDH. To start with the converter, we create a java class in the ViewController project and name it MyB2ZConverter.java. As package we choose ‘de.hahn.blog.convertersample.view.converter’

As the class will be a converter we have to implement the javax.faces.convert.Converter interface. For this you click on the green ‘+’ sign and can search for the right interface

This process will create the java class and two methods

These are the methods we have to implement for our use case. The first method ‘getAsObject’ is called when the data from the UI is send to the server for further processing. The ‘getAsString’ method is called when data from a storage (DB, bean property or pagedef variable) is going to be rendered to the UI.

As our use case is to exchange every “B” with the string “-Z-” we can implement the getAsString method easily by replacing every “B’ with “-Z-”. The method has three parameters, the current FacesContext which you can use to write messages, the UIComponent for which the converter is called and finally an Object representing the data which we want to convert. The result of the conversion must be a String. The resulting method look like

/** Method to get the string representation of hte object to use in the UI
* @param facesContext current facesContext
* @param uIComponent component which was used to deliver the data
* @param object data from storage to be converted
* @return sting to use for in the UI
*/
public String getAsString(FacesContext facesContext, UIComponent uIComponent, Object object) {
  if (object != null) {
    String ret = object.toString().replaceAll("B", "-Z-");
    return ret;
  } else {
    return null;
  }
}

After the check if the object to convert is null (in this case there is nothing to do), we use the String.replaceAll(…) method to search for ‘B’ and replace it with “-Z-”.

Keep in mind that the first parameter to the replaceAll method is a regular expression (see String.replaceAll(java.lang.String, java.lang.String)).

Now, if the data from the UI is send back to the model layer, it has to be converted back into the original format. So we have to do the conversion backwards by replacing all “-Z-” with “B” in the getAsObject(…) method:

/** Method which get the data from a uiComponent and should return it in the format we like to store in the DB (or elswhere)
* @param facesContext current facesContext
* @param uIComponent component which was used to deliver the data
* @param string data from the ui component
* @return object to use for further work (e.g. storage in the DB)
*/
public Object getAsObject(FacesContext facesContext, UIComponent uIComponent, String string) {
  if (string != null) {
    String ret = string.replaceAll("-Z-", "B");
    return ret;
  } else {
    return null;
  }
}

The result will be an Object which will be passed back to the model layer. If you don’t implement the getAsObject(…) method and just return the third parameter as resulting object, you would change every data in the back end to the new format. This may be your intention, but most often you don’t want to do this. It would mark every row of data dirty you have visited without any user interaction. This is because you pass different data back to the model than you read from it.

The last step to do is to register the custom converter in the faces-config.xml file of the ViewController project. Open the faces-config.xml file in JDev and select the ‘Converter’ tab

Click the green ‘+’ sign to get the an empty row in the converter section. Go to the property window and you see

Where we click on the ‘…’ button on the right end of the ‘Class’ field. We get the search for a class dialog where we look for the MyB2ZConverter class

Select the class and enter an ID fro the converter. This ID will be used in the UI to tell a component to use this converter.

Finally the converter section look like

UI Page

Now we can use the converter in a page or fragment. We start with a simple page where we define a inputText field and a button to submit the content of the field to see the converter working.

In the adfc-config.xml we add a JSPX page named ‘index’

And this page uses a quick layout as seen here

We add a title and the inputText field, a button to submit the data and two outputText fields to show what the converter has done to the data. The page layout looks like

or in code

If you like to copy the code use the following representation:

<?xml version='1.0' encoding='UTF-8'?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.1" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html"
 xmlns:af="http://xmlns.oracle.com/adf/faces/rich">
 <jsp:directive.page contentType="text/html;charset=UTF-8"/>
 <f:view>
 <af:document id="d1">
 <af:form id="f1">
 <af:panelStretchLayout topHeight="50px" id="psl1">
 <f:facet name="top">
 <af:outputText value="Converter Sample" id="ot1" inlineStyle="font-size:x-large;"/>
 </f:facet>
 <f:facet name="center">
 <af:panelGroupLayout layout="scroll" xmlns:af="http://xmlns.oracle.com/adf/faces/rich" id="pgl1">
 <af:inputText label="Enter String" id="it1" value="#{bindings.myInput1.inputValue}">
 <f:converter converterId="B2ZConverter"/>
 </af:inputText>
 <af:commandButton text="refresh" id="cb1"/>
 <af:outputText value="current data: #{bindings.myInput1.inputValue}" id="ot2"/>
 <af:outputText value="current data with converter: #{bindings.myInput1.inputValue}" id="ot3">
 <f:converter converterId="B2ZConverter"/>
 </af:outputText>
 <af:commandButton text="Converter with DB Data" id="cb2" action="emp"/>
 </af:panelGroupLayout>
 <!-- id="af_one_column_header_stretched" -->
 </f:facet>
 </af:panelStretchLayout>
 </af:form>
 </af:document>
 </f:view>
</jsp:root>

Hint: you might notice another component, a button which is later used to navigate to a second page. This is described later.

For the inputText field we need to store the data a user enters. For this we can either use a DB table, a bean property or a pagedef variable. We use a pagedef variable (more on see see Creating Variables and Attribute Bindings to Store Values Temporarily in the PageDef) which we bind to the value property of the inputText component (value=”#{bindings.myInput1.inputValue}”). The converter is setup by adding an f:converter tag like

<af:inputText label="Enter String" id="it1" value="#{bindings.myInput1.inputValue}">
  <f:converter converterId="B2ZConverter"/>
</af:inputText>

The converterId points to the ID defined in the faces-config.xml file. Running the page will show

Enter ‘Hello’ into the field and clicking outside the field (so that it looses the focus) will show

As we see, the two outputText fields don’t show anything as the data in not submitted jet. Clicking the ‘refresh’ button submits the data and the converter goes to action

Well, as the input did not have any ‘B’ nothing changes. So lets us add another word ‘Beta’ and click outside the inputText

As we did not submit the data to the server, we still see ‘Hello Beta’ and the outputText fields show ‘Hello’ both. Now click the ‘refresh’ button to get

The inputText has changed to the new format where the “B” is exchanged with the “-Z-”, however the outputtext ‘current data’ still shows the ‘Hello Beta’. The reason for this is that the data send to the binding layer was converted back using the getAsObject(…) method which exchanged the “-Z-” with “B”.

This implements the use case described at the beginning.

Now, to show that the same converter works with data from a DB table as well we add another two pages to the adfc-config.xml. One showing the employees in a read only table with a link on the employeeId which navigates to the employee details in a form.

The navigation to the second use case is done with the button mentioned earlier (‘Converter with DB data’)

Clicking on the button will show a table with employees where the EMail column was used to add the converter

The column tag looks like

<af:column sortProperty="#{bindings.EmployeesView1.hints.Email.name}" filterable="true" sortable="true"
    headerText="#{bindings.EmployeesView1.hints.Email.label}" id="c3">
  <af:outputText value="#{row.Email}" id="ot5">
    <f:converter converterId="B2ZConverter"/>
  </af:outputText>
</af:column>

Like with the inputText we just add a f:converter tag with the right ID “B2ZConverter”. With this use case we see why the getAsObject(…) method should undo the formatting. You don’t want to store the Email like this. You only want to show it this way, but not overwrite the correct Email fro the employee. You can check the DB data and see that the Email is still stored with the “B” and not the “-Z-”

To verify this we can click the link in the first column to goto the detail page of the selected employee

Again, we see the ‘Email’ in the new format and the original data ‘NO CONVERTER Email’ in the normal data. The tags used for this are

  <af:inputText value="#{bindings.Email.inputValue}" label="#{bindings.Email.hints.label}" required="#{bindings.Email.hints.mandatory}"
      columns="#{bindings.Email.hints.displayWidth}" maximumLength="#{bindings.Email.hints.precision}"
      shortDesc="#{bindings.Email.hints.tooltip}" id="it1">
    <f:validator binding="#{bindings.Email.validator}"/>
    <f:converter converterId="B2ZConverter"/>
  </af:inputText>
  <af:panelLabelAndMessage label="NO CONVERTER #{bindings.Email.hints.label}" id="plam1">
    <af:outputText value="#{bindings.Email.inputValue}" id="ot2"/>
  </af:panelLabelAndMessage>

When using the binding for the Email without the converter we see the data as it’s stored in the DB. Using the converter we see the converted data.

The sample was build with JDeveloper 11.1.1.17.0 using the HR DB schema. You can download the sample from GitHub BlogConverterSample.zip

JDev 12c: Change Label depending on Data in Field

A question on OTN forum JDev & ADF caught my attention. A user ask how to change the label of a field in an af:query depending on data entered in another field of the af:query.

This is an interesting problem as it can be used in other use cases, e.g. in forms, too.

Use case

Before going into detail on how this is implemented, let’s look at the use case in detail. Starting with a normal af:query component showing a search form for locations

We want to change the label of the ‘State’ field depending on the selected Value of the ‘CountryId’ field. The page is simply created by dragging the named criteria ‘All Queryable Attributes’ onto the page as ‘Query with Table’.

To make the UI more interesting we use an af:selectOneChoice to select the country. Depending on the selected country we like to show different labels for the ‘State’ field. If we select the ‘United States of America’ as country, the label should show ‘US States’, if we select ‘Germany’ we want to see ‘Bundesland’ and for Switzerland we want to show ‘Kanton’. For the remaining countries we show ‘State’.

Here we see that the label changed to ‘Kanton’ for the country Switzerland. Selecting the USA will change the label to ‘US State’

Implementation

To implement this we only need to add some groovy script to the model project. To be precise we add groovy to the attribute label of the view which is used in the UI for the af:query.

Adding the groovy to the view will guarantee that the UI always shows the effect. In the sample (download instructions below) you’ll find a second page where the view is dropped as a af:form. Running this page you’ll see the same effect.

OK, let’s have a look at the groovy script

if (CountryId == 'US') {
  return 'US State';
} else if (CountryId == 'DE') {
  return 'Bundesland';
} else if (CountryId == 'CH') {
  return 'Kanton';
} else if (CountryId != null) {
  return CountryId + ' State';
} else {
  return 'State';
}

The script checks for specific countries and depending on which country is currently selected it return a special label. For country ‘DE’ it return ‘Bundesland’, for country ‘CH’ it returns ‘Kanton’. For other countries we return the country code we get from the country attribute and add ‘State’ to it. A special case we have to handle is if country is null or empty. In this case we return ‘State’.

Below we see that we add the script to the attributes ‘UI Hint’ tab as ‘Label’. This is only possible in 12c, so if you are using an earlier version, you have to use java code to get the same result.

This is all we have to do. The sample which is build using JDev 12.2.1.2.0 can be downloaded from BlogChangeQueryLabel. The sample uses the HR DB schema.

Enable Oracle JCS to access External REST API

Enable Oracle JCS to access External REST API

For a training I’m preparing I had to implement a POC on how to access an external REST API and to make it available in an ADF application running in the Oracle Java Could Service.

This task sounds pretty easy, nevertheless it’s best to see this working before starting a training which in the end will not work.

I decided to use Spotify public available REST API at https://api.spotify.com for this task. I started by creating a simple Fusion Web Application using JDev version 12.2.1.2.0. To this project I added a custom model Project which I later used to add the REST DataControl pointing to the Spotify track search API.

As this post isn’t about how to create such a project and use it in your normal ADF application, I spare the details here and write this up in another blog post.

Implementing a REST DataControl is pretty straight forward and the sample application was set up quickly. The first problem you might run into, even on the local development machine is this

null

error you get when you try to access the public API from inside the WebLogicServer. To make this error searchable for other users here is a part of the stack trace

javax.net.ssl.SSLKeyException: Hostname verification failed: HostnameVerifier=weblogic.security.utils.SSLWLSHostnameVerifier, hostname=api.spotify.com.
at weblogic.security.SSL.jsseadapter.JaSSLEngine.doPostHandshake(JaSSLEngine.java:686)
at weblogic.security.SSL.jsseadapter.JaSSLEngine.doAction(JaSSLEngine.java:757)
at weblogic.security.SSL.jsseadapter.JaSSLEngine.unwrap(JaSSLEngine.java:133)
at weblogic.socket.JSSEFilterImpl.unwrap(JSSEFilterImpl.java:644)
at weblogic.socket.JSSEFilterImpl.unwrapAndHandleResults(JSSEFilterImpl.java:541)
at weblogic.socket.JSSEFilterImpl.doHandshake(JSSEFilterImpl.java:99)
at weblogic.socket.JSSEFilterImpl.doHandshake(JSSEFilterImpl.java:78)
at weblogic.socket.JSSESocket.startHandshake(JSSESocket.java:240)
at weblogic.net.http.HttpsClient.New(HttpsClient.java:574)
at weblogic.net.http.HttpsClient.New(HttpsClient.java:545)
at weblogic.net.http.HttpsURLConnection.connect(HttpsURLConnection.java:236)
at weblogic.net.http.HttpURLConnection.getInputStream(HttpURLConnection.java:685)
at weblogic.net.http.SOAPHttpsURLConnection.getInputStream(SOAPHttpsURLConnection.java:41)
at weblogic.net.http.HttpURLConnection.getResponseCode(HttpURLConnection.java:1545)
...

This problem can easily sorted out by changing the ‘Hostname Verification’ to custom and to specify ‘weblogic.security.utils.SSLWLSWildcardHostnameVerifier’ as ‘Custom Hostname Verifier’. Here are the detailed steps:

  1. Go to the WebLogic admin console -> Environment -> Servers -> Server -> Configuration -> SSL
  2. Under advanced options , change “Hostname Verification” from “BEA Hostname Verifier” to “Custom Hostname Verifier”.
  3. Set “Custom Hostname Verifier” to weblogic.security.utils.SSLWLSWildcardHostnameVerifier
  4. Click “Save” and then “Activate Changes”
  5. Restart your server.

After this the sample application will run on the local development machine or an stand alone webLogic Server.

Now the fun part begins, making the application run in the Oracle JCS. Here I started with setting up a new Java Cloud Service with a WebLogic Server of version 12.2.1.2 and deployed my local running application to this new JCS.

The application did start OK, but when I came to the point where the application tried to call the external REST API all I got is: NOTHING

I only saw a spinning cursor, no error message on the UI regardless of my exception handler. It turned out, that I did not wait long enough for the error message to come up. The REST call timed out eventually providing more info in the servers log file

Exception in invoking HTTP method GET from Rest data control. Cause: javax.ws.rs.ProcessingException: java.net.ConnectException: Tried all: 3 addresses, but could not connect over HTTPS to server: api.spotify.com port: 443

It looks like the external REST call is not allowed. Here is the REST call

https://api.spotify.com/v1/search?q=sorry&type=track

If you write this into your browser you’ll get a JSON string in return, something like

{
 "tracks" : {
 "href" : "https://api.spotify.com/v1/search?query=sorry&type=track&offset=0&limit=20",
 "items" : [ {
 "album" : {
 "album_type" : "album",
 "artists" : [ {
 "external_urls" : {
 "spotify" : "https://open.spotify.com/artist/1uNFoZAHBGtllmz…

telling me that the problem is somewhere with the JCS. I ask for help in the OTN Java Cloud Service space and got an answer that there must be a rule missing. This is true to some point as I tried to access the REST API with curl from the JCS command shell

null

which did not work either. The interesting part is that you can do the same from the DBCS command shell and get the right answer.

I tried to add a rule to allow the access but looking at the possible source and destinations lists this did not work. Only

  • OTD — The Oracle Traffic Director load balancer VMs
  • WLS_ADMIN_SERVER — The WebLogic Server Administration Server VM
  • WLS_MANAGED_SERVER — The WebLogic Server Managed Server VMs

are allowed as destinations and my rule should allow the managed server (source) to access the PUBLIC_INTERNET or allow access to https protocol port 443.

After some more reading and testing I found a solution, however I’m not sure if this is the best way to handle this. Anyway, for others users who run into the same problem here it is:

First you have to create a ‘Security List’ Which you name e.g. outbound_wlsms_https_traffic which denies incoming packages and allows outgoing packages

null

Next a ‘Security Rule’ can be created like

null

with source set as the managed server and destination the new security list. After that the access to the external REST API works.

Use LOV without af:selectoneChoice

A question on the JDev & ADF forum caught my attention. A user asked how to get the attribute value from a list of value (LOV) without using an af:selectOneChoise component. To make the use case clear, let’s look at a listview from the Departments table of the HR DB schema.

this will produce a very rudimentary output like

Selection_030

This doesn’t look charming. OK we can change this to something more meaningful like

Selection_031

But still we see only the key values instead meaningful attribute values like we get if we use a af:selectOneChoce component.

To get the output using an af:selectOneChoise we need to define list of values at the attributes in the view object, DepartmentsView in this case:

Now, when we drag the DepartmentsView onto a page and drop it as a form or table we would get the af:selectOneChoice component. However, if we create the listview again, nothing changes. JDev uses af:outputText components in this case.

To show the managers name behind the ManagerId, we can e.g. add another attribute to the view and get the manager name via a join in the sql query.

Or we put a af:selectOnChoice in the list view cell like we get for a cell in a table. This would look like

 <af:panelGroupLayout id="pgl3" layout="horizontal">
   <af:outputFormatted value="ID: #{item.bindings.ManagerId.inputValue} Name:" id="of2"/>
   <af:selectOneChoice value="#{item.bindings.ManagerId.inputValue}" label="#{row.bindings.ManagerId.label}"
     required="#{bindings.DepartmentsView1.hints.ManagerId.mandatory}"
     shortDesc="#{bindings.DepartmentsView1.hints.ManagerId.tooltip}" id="soc3" disabled="true">
     <f:selectItems value="#{item.bindings.ManagerId.items}" id="si3"/>
     <f:validator binding="#{item.bindings.ManagerId.validator}"/>
   </af:selectOneChoice>
 </af:panelGroupLayout>

and generate

Selection_039

The gray rectangle is because we have set the disabled property to true to disable the component. To get a better look we can set the readOnly property instead to get

Selection_040

which look much better. However to get this result we have to add a lot of tags to the page.

The final solution is to use the data which is present in the model to show the attribute name instead of the value like it’S done ba the framework for af:selectOneChoice. For this we only need one af:outputText tag like

 <af:outputFormatted value="ID: #{item.bindings.ManagerId.inputValue} Name: #{item.bindings.ManagerId.items[item.bindings.ManagerId.inputValue].label}"
 id="of1"/>

This will generate

Selection_041.png

The magic is the expression language

#{item.bindings.ManagerId.items[item.bindings.ManagerId.inputValue].label}"

which uses the items defined for the selectOneChoice and located the right display attribute in the collection using the attribute value.

You can download the sample application which is build with JDev 12.2.1.2 and uses the HR DB schema from GitHub BlogShowLOVattributeWithoutLOV