Changing LogManager configuration in WebStart

Question

I have an application that I intend to deploy with WebStart. The application uses the java.util.logging features to display log messages to a Swing control on the screen. I've implemented a class that extends Handler to receive the messages logged to the LogManager. I added this handler to the logging.properties file to load at start time. This all works fine when I run as a standalone application from a jar file.
I've run into several problems when I try to deploy with WebStart:
First, webstart does not seem to honor the System properties "java.util.logging.config.class" and "java.util.logging.config.file." I've set these in my .jnlp file and can see that they are properly set in my main routine, but they appear to be ignored by javaws.exe at startup. It appears that webstart sets the LogManager with a predefined configuration.
Second, if I do force the LogManager to read a new configuration using the readConfiguration(InputStream) method, any classes (Handlers) that are not on the system classpath at startup time cannot be found when it comes time to log messages to them. I'm guessing that this is caused by the fact that a different class loader is assigned to the logging thread than the loader for the application (Bug 4665132).
Does anyone have any clues as to how I might get a new handler into the LogManager?
Thanks in advance.

Answer 1

I m using the extension tag in jnlp file but unable to load my custom handlers
both JNLP file:
// main - file
<?xml version="1.0" encoding="utf-8" ?>
<jnlp spec="1.5+" codebase="http://192.168.0.147/main/" href="main.jnlp">
<information>
     <homepage href="." />
     <title>FTKHI</title>
     <vendor>Test</vendor>
     <description>Test</description>
     <description kind="short">test</description>
     <icon href="images/logo.jpg" />
     <icon kind="splash" href="images/logo.jpg"/>
     <offline-allowed />
</information>
<security>
     <all-permissions />
</security>
<resources>
     <j2se version="1.4.2+" />
          <jar href="lib/com.jar" main="true"/>
     <extension name="support" href="install/support.jnlp"/>
<property name="sun.awt.exception.handler" value="com.support.packages.swing.java.SwingAssertionExceptionHandler" />
<property name="java.net.preferIPv4Stack" value="true" />
<property name="com.support.packages.registry.URL" value="http://192.168.0.147/iil/Registry.conf"/>
</resources>
<application-desc main-class="com.iil.components.iil.java.Main" />
</jnlp>
// support - file
<?xml version="1.0" encoding="utf-8" ?>
<jnlp spec="1.5+" codebase="http://192.168.0.147/iil/install/" href="support.jnlp">
<information>
     <homepage href="." />
     <title>supportLib</title>
     <vendor>Lib</vendor>
     <description>Library</description>
     <description kind="short">ABCD</description>
     <icon href="images/logo.jpg" />
     <icon kind="splash" href="images/logo.jpg"/>
     <offline-allowed />
</information>
<security>
     <all-permissions />
</security>
<resources>
          <jar href="../lib/support.jar" />
          <jar href="../lib/activation-1.0.2.jar" />
          <jar href="../lib/CalendarBean.jar" />
          <jar href="../lib/commons-beanutils-bean-collections.jar" />
          <jar href="../lib/commons-beanutils-core.jar" />
          <jar href="../lib/commons-beanutils.jar" />
          <jar href="../lib/commons-chain-1.0.jar" />
          <jar href="../lib/commons-collections-3.1.jar" />
          <jar href="../lib/commons-digester-1.7.jar"/>
          <jar href="../lib/commons-collections-testframework-3.1.jar" />
          <jar href="../lib/commons-lang-2.0.jar" />
          <jar href="../lib/commons-logging-api.jar" />
          <jar href="../lib/commons-logging.jar" />
          <jar href="../lib/gnu.jar" />
          <jar href="../lib/itext-1.3.1.jar" />
          <jar href="../lib/jasperreports-1.2.0.jar" />
          <jar href="../lib/jbcl.jar" />
          <jar href="../lib/junit-3.8.2.jar" />
          <jar href="../lib/mail-1.3.3.jar" />
          <jar href="../lib/msbase.jar" />
          <jar href="../lib/mssqlserver.jar" />
          <jar href="../lib/msutil.jar" />
          <jar href="../lib/mysql-connector-java-3.1.11-bin.jar" />
          <jar href="../lib/poi-2.5.jar" />
          <jar href="../lib/velocity-1.4.jar" />
          <jar href="../lib/velocity-dep-1.4.jar" />
          <jar href="../lib/velocity-tools-generic-1.1.jar" />
</resources>
<resources os="Windows">
          <nativelib href="../lib/win32/support.nativewin32.jar"/>
</resources>
<component-desc/>
</jnlp>
the support.jar contains the CustomHandlers for logging.
yet i m getting the same
Can't load log handler "com.support.packages.logger.java.ExceptionHandler"
java.lang.ClassNotFoundException: com.support.packages.logger.java.ExceptionHandler
java.lang.ClassNotFoundException: com.support.packages.logger.java.ExceptionHandler
     at java.net.URLClassLoader$1.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at java.util.logging.LogManager$7.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.util.logging.LogManager.initializeGlobalHandlers(Unknown Source)
     at java.util.logging.LogManager.access$900(Unknown Source)
     at java.util.logging.LogManager$RootLogger.getHandlers(Unknown Source)
     at java.util.logging.Logger.log(Unknown Source)
     at java.util.logging.Logger.doLog(Unknown Source)
     at java.util.logging.Logger.log(Unknown Source)
     at com.support.packages.logger.java.Logger.log(Logger.java:34)
     at com.support.packages.event.java.EventThread.run(EventThread.java:173)
     at java.lang.Thread.run(Unknown Source)
and if i copy all these files to jre/lib/ext dir manually then its works fine but dont want this solution. Please solve my prob