Get the generated source code for JSPs in WebLogic

Keywords:
generated JSP java class source Oracle WebLogic line numbers

Problem:
Given a stack trace such as the following:

java.lang.NullPointerException
 at jsp_servlet._web_45_inf._jsp._demo.__example._jspService(__example.java:117)
 at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)
 at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
 at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
 at weblogic.servlet.internal.ServletStubImpl.onAddToMapException(ServletStubImpl.java:416)
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:326)
 at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
 at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:526)
 at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)

It won't always be obvious what the issue in example.jsp corresponds to in the generated __example.java. How do you get at the generated source code for the JSPs?

Solution:
The solution involves configuring a [app_name]/WEB-INF/weblogic.xml file in your web-app. The documentation is in the WebLogic 10.3 docs - see weblogic.xml Deployment Descriptor Elements but keep in mind the file will be validated against the schema so the elements must be in the correct spot.

Below is an example - defining the jsp-descriptor with keepgenerated and working-dir elements:

<?xml version="1.0" encoding="UTF-8"?>
<weblogic-web-app
    xmlns="http://www.bea.com/ns/weblogic/90"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.bea.com/ns/weblogic/90 http://www.bea.com/ns/weblogic/90/weblogic-web-app.xsd">
    <jsp-descriptor>
        <keepgenerated>true</keepgenerated>
        <working-dir>c:/my_folder/temp</working-dir>
    </jsp-descriptor>
    <container-descriptor>
        <prefer-web-inf-classes>true</prefer-web-inf-classes>
    </container-descriptor>
</weblogic-web-app>