Remote debugging wiht Eclipse

The Java Debugger


The Java Debugger (jdb) is a dynamic, controlled, assignment-based debugging tool. It helps find and fix bugs in the Java language programs both locally and on the server. To use jdb in a J2EE application server you must first launch it with debugging enabled and attach to the server from the debugger through a JPDA port (Default port is 1044).

The default JPDA options for J2EE servers are as follows:

-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=1044



The jdb parameters specify the way debugger will operate. For instance transport=dt_socket instructs the JVM that the debugger connections will be made through a socket while the address=1044 parameter informs it that the port number will be 1044. Similarly, if you substitute suspend=y , the JVM starts in suspended mode and stays suspended until a debugger is attached to it. This may be helpful if you want to start debugging as soon as the JVM starts.


Debugging WebLogic

Debugging WebLogic is no different than debugging any other Java remote application. You need to make sure to launch it with the required debugging arguments and attach a debugger. In the case of WebLogic 8.1, you need to add these arguments to the startup script. WebLogic comes with several launch scripts (*.sh and *.cmd) under BEA_HOME/weblogic81/server/bin.

Locate startWSL.cmd and add the following variable DEBUG_OPTS:

set DEBUG_OPTS = -Xdebug -Xrunjdwp:transport= dt_socket,address=1044,server=y,suspend=n

Next, insert the new variable to the WebLogic startup command, after "%JAVA_HOME%\bin\java" and preferably before the other options.

Your startup script should look like:

"%JAVA_HOME%\bin\java" %DEBUG_OPTS% %JAVA_VM% %MEM_ARGS% %JAVA_OPTIONS%-Dweblogic.Name=%SERVER_NAME% -Dweblogic.management.username= %WLS_USER%-Dweblogic.management.password= %WLS_PW% -Dweblogic.management.server= %ADMIN_URL%-Dweblogic.ProductionModeEnabled= %PRODUCTION_MODE%-Djava.security.policy= "%WL_HOME%\server\lib\weblogic.policy" weblogic.Server

Debugging JBoss

Same as WebLogic, except that you need to change run.bat/run.sh located under JBOSS_HOME/bin.
Linux users should see something similar to this:
$ cd /var/jboss4/bin
$ sh ./run.sh

=========================================================================
JBoss Bootstrap Environment

JBOSS_HOME: /var/jboss4

JAVA: /usr/java/j2sdk1.4.2_06/bin/java

JAVA_OPTS: -server -Xms128m -Xmx128m -Dprogram.name=run.sh

DEBUG_OPTS = -Xdebug -Xrunjdwp:transport= dt_socket,address=1044,server=y,suspend=n

CLASSPATH: /var/jboss4/bin/run.jar:/usr/java/j2sdk1.4.2_06/lib/tools.jar
=========================================================================