Errors starting an application

What kind of error do you see when you start an application?

HTTP server and Application Server are working separately, but requests are not passing from HTTP server to Application Server

If your HTTP server appears to be functioning correctly, and the Application Server also works on its own, but browser requests sent to the HTTP server for pages are not being served, a problem exists in the WebSphere Application Server plug-in.

In this case:

  1. Determine whether the HTTP server is attempting to serve the requested resource itself, rather than forwarding it to the WebSphere Application Server.
    1. Browse the HTTP server access log (IHS install root\logs\access.log for IBM HTTP Server). It might indicate that it could not find the file in its own document root directory.
    2. browse the plug-in log file as described below.
  2. Refresh the install_dir/config/plugin-cfg.xml file that determines which requests sent to the HTTP server are forwarded to the WebSphere Application Server, and to which Application Server. You might need to refresh this file:
    • In the WebSphere Application Server administrative console, expand the Environment tree control.
    • Click Update WebSphere Plugin.
    • Stop and restart the HTTP server and retry the Web request.
  3. Browse the install_dir/logs/http_plugin.log file for clues to the problem. Make sure the timestamps with the most recent plug-in information stanza, which is printed out when the plug-in is loaded, correspond to the time the Web server started.
  4. Turn on plug-in tracing by setting the LogLevel attribute in the install_dir/config/plugin-cfg.xml file to Trace and reloading the request. Browse the install_dir/logs/http_plugin.log file. You should be able to see the plug-in attempting to match the request URI with the various URI definitions for the routes in the plugin-cfg.xml. Check which rules the plug-in is not matching against and then figure out if you need to add additional ones. If you just recently installed the application you might need to manually regenerate the plug-in configuration to pick up the new URIs related to the new application.

File serving problems

If text output appears on your JSP- or servlet-supported Web page, but image files do not:

Graphics do not appear in the JSP file or servlet output

If text output appears on your JSP- or -servlet-supported Web page, but image files do not:

SRVE0026E: [Servlet Error]-[Unable to compile class for JSP file

If this error appears in a browser when trying to access a new or modified .jsp file for the first time, the most likely cause is that the JSP file Java source failed (was incorrect) during the javac compilation phase.

Check the log files for a compiler error message, such as:

Duplicate variable declaration: int myInt was int myInt
int myInt = 122; 
String myString = "number is 122"; 
static int myStaticInt=22; 
int myInt=121; 
      ^
Fix the problem in the JSP source file, save the source and request the JSP file again.

If this error occurs when trying to serve a JSP file that was copied from another system where it ran successfully, then there is something different about the new server environment that prevents the JSP file from running. Browse the text of the error for a statement like:

 Undefined variable or class name: MyClass
This error indicates that a supporting class or jar file is not copied to the target server, or is not on the class path. Find the MyClass.class file, and place it on the Web module WEB-INF/classes directory, or place its containing .jar file in the Web module WEB-INF/lib directory.

Verify that the URL used to access the resource is correct by completing the following steps:

Correct the URL in the "from" HTML file, servlet or JSP file. An HREF with no leading slash (/) inherits the calling resource context. For example:

Message like "Message: /jspname.jsp(9,0) Include: Mandatory attribute page missing" appears when attempting to browse JSP file

It is probable that the JSP file failed during the translation to Java phase. Specifically, a JSPdirective, in this case an Include statement, was incorrect or referred to a file that could not be found.

To correct this problem, fix the problem in the JSP source, save the source and request the JSP file again.

The JSP Batch Compiler fails with the message "Enterprise Application [application name you typed in] not found."

It is probable that the full enterprise application path and name, starting with the .ear subdirectory that resides in the install_root\config\cells\node_nameNetwork\applications directory is expected as an argument to the JspBatchCompiler tool, not just the display name. For example:

There is a translation problem with non-English browser input.

If non-English-character-set browser input cannot be translated after being read by a servlet or JSP file, ensure that the request parameters are encoded according to the expected chararacter set before reading. For example, if the site is Chinese, the target .jsp file should have a line:

 req.setCharacterEncoding("gb2312");
before any req.getParameter() calls.

This problem affects servlets and jsp files ported from earlier versions of WebSphere Application Server, which converted characters automatically based upon the locale of the WebSphere Application Server.

Scroll bars do not appear around items in the browser window

In some browsers, tree or list type items that extend beyond their allotted windows do not have scroll bars to permit viewing of the entire list.

To correct this problem, right-click on the browser window and click Reload from the menu.

Error "Page cannot be displayed... server not found or DNS error" appears when attempting to browse a Java Server Page (JSP) using Internet Explorer

This error can occur when an HTTP timeout causes the servant to be brought down and restarted. To correct this problem, increase the ConnectionIOTimeOut . value:

  1. From the adminstrative console select Servers > Application Servers > <server name> > Web Container > Custom Properties
  2. Select ConnectionIOTimeOut
  3. Increase the ConnectionIOTimeOut value
  4. Click OK.


Related tasks
Troubleshooting by task: What are you trying to do?
Related reference
A web resource does not display



Searchable topic ID:   rtrb_pagedisplayprob2
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
http://publib.boulder.ibm.com/infocenter/wasinfo/index.jsp?topic=/com.ibm.websphere.zseries.doc/info/zseries/ae/rtrb_pagedisplayprob2.html

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