Legacy upgrade from JBOSS 3.2.3 to 4.2.2 resulting in null pointer errors

Greenhorn

Posts: 2

posted 13 years ago

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Hey Folks-
I am pretty much a newb to JSP and have been tasked with upgrading one of our existing applications (8 years old) to our "latest" supported version of JBOSS (4.2.2). Please don't laugh. I work for the State. Anyway... The app runs fine under JBOSS 3.2.3. But when I try to run it under 4.2.2, I get the following error when I attempt to call a method on one of my value beans:

12:32:22,953 ERROR [[jsp]] Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at com.synsoltec.dwconsole.web.jspinputs.JSPInputs.getTitle(JSPInputs.java:111)
at org.apache.jsp.SST.JSP.Layouts.IncludeHeader_jsp._jspService(IncludeHeader_jsp.java:75)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.j
ava:290)

My (partial) JSP looks like this (note the scope of the useBean = request):

...and the relevant bean JSPInputs looks like this:

public class JSPInputs implements Serializable {  
  
  /**
	 * 
	 */
  private static final long serialVersionUID = 5860806058831923065L;
  public static String JSP_INPUTS="jspinputs";   
  private ServletRequest request;
  private String onLoadURL = null;
    
  //default no-arg constructor
  public JSPInputs()
  {
	  //init();
  }
   
  public JSPInputs(ServletRequest request){    
	//init();
    addTo(request);  
    this.request=request;
    if (request!=null && request.getAttribute(AbstractRequestHandler.USER_MESSAGE)!=null)
      userMessage=(UserMessage)request.getAttribute(AbstractRequestHandler.USER_MESSAGE);
  }

/** This is sort of a biggest title 
   *  gyows - modified from "null" to "" to test app behavior 
   *  under new version of JBOSS.
   * */
  //public String applicationTitle="";  
  public String applicationTitle=null;
  
  /** This is sort of a lesser title, usually displayed 
   *  gyows - modified from "null" to "" to test app behavior 
   *  under new version of JBOSS.
   * */  
  //public String pageTitle="";
  public String pageTitle=null;
  
  public ActionManager actionManager=null;
  public NavigationManager navManager=null;
  public TabManager tabManager=null;
  public ResourceMap resources=null;
  private UserMessage userMessage=null;

public Tab[] tabs = null;
  
[other methods here]

//////////////////
  // Title-o-rama //
  //////////////////
  private String[] titles=new String[4];
  public String getTitle(int level){
    level--;
    if (level==0 && titles[0]==null)
      return tabManager.getTabManagerTitle()+applicationTitle;
    else 
    if (level==1 && titles[1]==null)
      return applicationTitle;
    else
    if (level==2 && titles[2]==null)
      return pageTitle;
    else
      return titles[level];
  }
  public JSPInputs setTitle(int level, String s){
    level--;
    titles[level]=s;
    return this;
  }
...

I did make the upgrade changes to to my value classes (classes used/called by my JSP useBean properties) that I know about. Specifically, adding a no-arg constructor and implementing the Serializable interface. Running through the debugger, I can see that there is supposed to be a number of objects / properties that should be available to to JSPInputs, but these are not created/ instantiated under JBOSS 4.2.2. This is part of a navigation framework that is trying to build up a header for the next page (by the way...not sure if that is important).

Any suggestions would be greatly appreciated. Thanks!

Gregg Yows

Greenhorn

Posts: 2

posted 13 years ago

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Really? Nobody has a clue what is going on here? I'm currently diffing my jar files between each server to see if it is a class-loading issue. Please help. Thanks.

Jaikiran Pai

Sheriff

Posts: 10445

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posted 13 years ago

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at com.synsoltec.dwconsole.web.jspinputs.JSPInputs.getTitle(JSPInputs.java:111)

In the code you posted, which line is 111? Have you checked which object is null?

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