Echoes of a Java/SOA Developer

ADF code corner moved

2010-09-01T21:37:00.000+02:00

OTN has been undergoing a change and therefor all links and references changed.
The ADF code corner can now be found at the following link:

http://www.oracle.com/technetwork/developer-tools/adf/learnmore/index-101235.html

This is a site with as-is coding examples of ADF

Usage of equals in Java

2010-02-12T10:33:00.001+01:00

Every now and then I take a look on a projects java source code on the web.
I still am amazed that most of that code do not use some basic coding rules.

One of these is to check objects with equals to a static string.
This is mostly done as:


private static final String STATIC_TEXT = "Static Text";

if(object.equals(STATIC_TEXT)
{
.....
}

The though part about this is that people do not see the danger in this.
The fact is that (most) objects in java are initiated with null if.
So the case shown above could result in an easy nullpointerexception.
While this is not necessary, this could be prevented by changed sequence in which you execute this statement.

<br />private static final String STATIC_TEXT = "Static Text";<br /><br />if(STATIC_TEXT.equals(object)<br />{<br />.....<br />}<br />

When changed like this the exception will not occur, only the check will result in 'false'.
Keep in mind that the code than needs to handle a null object(s).

To prevent that the usual check '!= null' can always be executed.
But by putting the objects in the right order it will prevent a lot of unnecessary searches for errors.

Error using upgrade assistant in JDeveloper 11.1.1.2.0

2010-01-14T12:27:00.002+01:00

Today I was running the upgrade assistant in JDeveloper 11.1.1.2.0 to migrate an ear file to see if we can get a quick deployment on the WLServer.
But then I suddenly received the following error:


31:57 WARNING - *** 
[ERROR] Action in Web Service Artifact Generation 10.1.3javax.script.ScriptException: sun.org.mozilla.javascript.internal.WrappedException: Wrapped java.lang.NullPointerException (<Unknown Source>#10)    at com.sun.script.javascript.RhinoCompiledScript.eval(RhinoCompiledScript.java:41)    at oracle.migration.action.ScriptBody.execute(ScriptBody.java:122)    at oracle.migration.action.Action.eval(Action.java:210)    at oracle.migration.action.Action.execute(Action.java:176)    at oracle.migration.action.Action.doAction(Action.java:227)    at oracle.migration.action.Action.doFinally(Action.java:231)    at oracle.migration.action.Action.execute(Action.java:188)    at oracle.migration.rule.MigrationRule.performAction(MigrationRule.java:808)    at oracle.migration.update.Updator$ActionContent.doUpdate(Updator.java:100)    at oracle.migration.update.Updator.doUpdate(Updator.java:110)    at oracle.migration.rule.MigrationRule.doUpdate(MigrationRule.java:788)    at oracle.migration.rule.MigrationRule.doUpdate(MigrationRule.java:781)    at oracle.migration.Migrator.generateArtifacts(Migrator.java:762)    at oracle.migration.MigrationPlan.doMigration(MigrationPlan.java:511)    at oracle.migration.MigrationPlan.execute(MigrationPlan.java:438)    at oracle.weblogic.jdeveloper.migration.io.WLMigrationManager.executeArchiveFindings(WLMigrationManager.java:288)    at oracle.weblogic.jdeveloper.migration.addin.application.ArchiveMigrationContext.regenerateFindings(ArchiveMigrationContext.java:85)    at oracle.weblogic.jdeveloper.migration.addin.application.ArchiveMigrationContext.continueUpgrade(ArchiveMigrationContext.java:131)    at oracle.weblogic.jdeveloper.migration.addin.command.ContinueUpgradeCommand.run(ContinueUpgradeCommand.java:89)    at oracle.toplink.workbench.utility.command.CommandWorker.run(CommandWorker.java:61)Caused by: sun.org.mozilla.javascript.internal.WrappedException: Wrapped java.lang.NullPointerException (<Unknown Source>#10)    at sun.org.mozilla.javascript.internal.Context.throwAsScriptRuntimeEx(Context.java:1699)    at sun.org.mozilla.javascript.internal.MemberBox.invoke(MemberBox.java:147)    at sun.org.mozilla.javascript.internal.NativeJavaMethod.call(NativeJavaMethod.java:190)    at sun.org.mozilla.javascript.internal.Interpreter.interpretLoop(Interpreter.java:3073)    at sun.org.mozilla.javascript.internal.Interpreter.interpret(Interpreter.java:2239)    at sun.org.mozilla.javascript.internal.InterpretedFunction.call(InterpretedFunction.java:138)    at sun.org.mozilla.javascript.internal.ContextFactory.doTopCall(ContextFactory.java:323)    at sun.org.mozilla.javascript.internal.ScriptRuntime.doTopCall(ScriptRuntime.java:2747)    at sun.org.mozilla.javascript.internal.InterpretedFunction.exec(InterpretedFunction.java:149)    at com.sun.script.javascript.RhinoCompiledScript.eval(RhinoCompiledScript.java:37)    ... 19 moreCaused by: java.lang.NullPointerException    at java.io.File.<init>(File.java:222)    at oracle.migration.ws.config.cli.SmartUpgradeEntry.createContinuationStateFile(SmartUpgradeEntry.java:285)    at oracle.migration.ws.config.cli.SmartUpgradeEntry.upgrade(SmartUpgradeEntry.java:174)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:37)    at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)    at java.lang.reflect.Method.invoke(Method.java:597)    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:244)    at sun.org.mozilla.javascript.internal.MemberBox.invoke(MemberBox.java:132)    ... 27 more[INFO]: script file: 
null
script line: 

   extraArgs=migrator.getLocator("_cliArgs")
   if (extraArgs==null) {
          map = null;
   } else {
          leaves=extraArgs.getLeafMigrationElements(rule) 
          migEl=leaves.get(0)   
          map=migEl.getArtifact()     
   } 
          Packages.oracle.migration.ws.config.cli.SmartUpgradeEntry.upgrade(rule, migrationElement, map, targetVersion)
      ot=Packages.oracle.migration.ws.config.cli.SmartUpgradeEntry.getOutString();
          migrationElement.setAttribute("ws.upgrade.out", ot)

  
script code: 
null

I did not see this in previous migrations.........

After a while of debugging and looking for certain errors finally it came to mind that spaces in paths of imported files could be disastrous.

The error changed a bit, now it could find de ear but still ended in a nullpointer exception :-(
The fix for this that the whole workspace and project also had a space in the path.
After changing this the upgrade went through and we could continue looking into the migration of all parts for the ear......

Change login screen for Gnome

2009-11-27T00:05:00.021+01:00

Since Fedora 11 the Gnome theme always show the available users in a list.
This is a risk because people can see which user(s) there are available on a system.

This behavior can be changed by the following command:

su -
gconftool-2 --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --direct --type bool --set /apps/gdm/simple-greeter/disable_user_list true

With this the "normal" login screen is returned.
Only the "others" is still availbale for selection
You need to know the username and the password B-)

Fedora 12 and dual screen with Gnome panels (and how to move them)

2009-11-20T23:42:00.001+01:00

After installing Fedora 12 in my installation the panels stayed on the screen of my laptop. While the monitor setup beside it is the primary window to work on. So I could not drag them to the other screen.

After some googling I found this link and this works for me:
In short the solution is one of the following:

press ALT and then click the panel and move it to the position you want
Right mouse click on the panel and select properties. Then unmark the 'expand' property. This will enable you to drag them to any place on the screen. When all is positioned check the 'expand' property back again and all will work fine.

This helps a lot in the way to work.

New release of Fedora ;-)

2009-11-19T08:55:00.001+01:00

Get your chance to see the new Fedora Constatine !!!!!!

Oracle WebLogic Server 11g Release 1 (10.3.2) released!!

2009-11-11T00:15:00.001+01:00

You can read about it here!

Or you can directly start with downloading here!

Have fun!

Oracle FMW 11g (11.1.1.2.0) released!!

2009-11-11T00:11:00.002+01:00

You can read about it here!

Or you can directly start with downloading here!

Have fun!

Install Oracle XE on Fedora 11 x86_64

2009-07-08T23:10:00.003+02:00

In order to install the oracle xe database on Fedora x86_64.
Download the oracle-xe-univ-10.2.0.1-1.0.i386.rpm.

In the installation guide is stated that the following packages are necessary.

glibc – 2.3.2
libaio – 0.3.96

So I installed these packages:
yum install glibc libaio

The installed the rpm : rpm -ivh oracle-xe-univ-10.2.0.1-1.0.i386.rpm
And then executed
"/etc/init.d/oracle-xe configure"
Which successfully ran with given answers to the questions.

After this I tried to start the database and got many different error messages.
Tried to start the database but nothing was started.
But there was nothing coming up.

Also tried "sqlplus /NOLOG"
connect / as sysdba
startdb

Then the errors stated there was not INITXE.ORA, so created the initXE.ora.
The following errors where the database files were not located.....

After numerous attempts and failing every time I uninstalled the rpm.
rpm -e oracle-xe-univ-10.2.0.1-1.0.i386.rpm

And removing all installed files "rm -rf /usr/lib/oracle/xe"

After some googling... It came to mind I am running a 64bit machine and the rpm is for a i386.
So I installed also the i586 packages:
yum install glibc.i686 libaio.i586

After this reinstalled the rpm : rpm -ivh oracle-xe-univ-10.2.0.1-1.0.i386.rpm

and configured the database.
Now all is running perfectly.....

Changing the font of JDeveloper 11R1 on Linux

2009-07-06T23:50:00.001+02:00

Just installing the new release of JDeveloper 11.

But when running on Linux the font size seems a little bit off.
In order to make this better to look at a chane is needed in the ide.properties.

This file is located at: ~/.jdeveloper/system11.1.1.1.33.54.07/o.jdeveloper
There is a commented field "# Ide.FontSize=11"
Changed it to 'Ide.FontSize=10' and then started JDeveloper that looked a lot better........

Howto run ADF with a Node Manager

2009-03-24T00:27:00.005+01:00

I am working now more and more with weblogic.
So I normally ran simple ADF web applications from JDeveloper.

Now I tried to deploy an ADF webapplication on a server running an AdminServer and a Managed Server set-up to be recovered by the node manager.
But during deploy the only error received is a "java.lang.ClassNotFoundException: "

Either on "oracle.adf.share.weblogic.listeners.ADFApplicationLifecycleListener" or on "javax.faces.webapp.FacesServlet".

But when running the Managed Server from the commandline all seem to work fine..........

The catch is in the classpath.
The nodemanager is NOT using the same startup script as available in your domain directory (see further below).

So a change needs to be made to the nodemanager:
Add the following code in the <WLS_HOME>/server/bin/startNodeManger.sh (or .cmd).


ORACLE_HOME="/opt/products/oracle/WLS103/jdeveloper"
export ORACLE_HOME

ADF_CLASSPATH="${ORACLE_HOME}/modules/features/adf.share_11.1.1.jar"
export ADF_CLASSPATH

set -x
CLASSPATH="${WEBLOGIC_CLASSPATH}${CLASSPATHSEP}${CLASSPATH}${CLASSPATHSEP}${BEA_HOME}${CLASSPATHSEP}${ADF_CLASSPATH}"
export CLASSPATH

By doing so the start of a managed server is made ADF aware and therefor deployments will result in a deployment on a server that uses the nodemanager...

There is a second solution to this problem.
The nodemanager.properties can be adjusted.
The properties for start and stop scripts needs to be enabled.


StopScriptEnabled=true
StartScriptEnabled=true

By this the classpath is set through the scripts created when the domain is also created...

Open a file in a JDeveloper Extension.

2009-02-19T10:56:00.007+01:00

Since a few months I now run Linux.
And I am using the PMD plugin for JDeveloper.
After the upgrade of JDeveloper to the latest version 11.1.1.0.1 the preferences are always gone.
So I wanted to import my settings again, but the file selector did not come up!

So looking into the log I saw the following stacktrace:
Exception occurred during event dispatching:

java.lang.ClassCastException: sun.awt.NullComponentPeer cannot be cast to sun.awt.X11.XChoicePeer
    at sun.awt.X11.XFileDialogPeer.init(XFileDialogPeer.java:264)
    at sun.awt.X11.XFileDialogPeer.show(XFileDialogPeer.java:726)

with the following code to open the dialog

final FileDialog fdlg = new FileDialog(new Frame(), "Import", FileDialog.LOAD);
fdlg.setVisible(true);

Looking throug a lot of (blog) post I could not get a fix for this.
So the thing that intrigued by the fact that the JDeveloper File chooser was working.
But that was not the Java default file chooser.

Then the question arises how can I use the JDeveloper file chooser?

A quest was up to get through the knowledge where a description is on the JDeveloper File Chooser.

I finally found it in an extension I also did some work on, the search extension.

It is needed to use the following code:

    public String getPath(String windowText, String currPath)
    {
      String returnPath = "";
     
      URL url = URLFactory.newDirURL( Ide.getSystemDirectory() );
      URLChooser chooser = DialogUtil.newURLChooser( url );
      chooser.setSelectionMode( URLChooser.SINGLE_SELECTION );
      chooser.setSelectionMode( URLChooser.FILES_ONLY);
      int ret = chooser.showOpenDialog( Ide.getMainWindow(), windowText);
      if ( ret == URLChooser.APPROVE_OPTION )
      {
        URL selectedURL = chooser.getSelectedURL();
        returnPath = URLFileSystem.getPlatformPathName( selectedURL ) ;
      }
      return returnPath;
    }

With this also on Linux it will work to import or export files into the PMD plugin.