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what is causing this java error?

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6 replies

by shimshai

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I have imported several tables of data into an sql server db with an html interface from another DB using odbc.
All the tables seem to work fine except when i try to view locations.
I then get the following error page:

Unexpected Exception
------------------
The exception is :- java.lang.NullPointerException
at psdi.app.location.Location.isStore(Location.java:604)
at psdi.app.location.Location.init(Location.java:161)
at psdi.mbo.MboSet.generateMboInstance(MboSet.java:1363)
at psdi.mbo.MboSet.fetchMbos(MboSet.java:1560)
at psdi.mbo.MboSet.getMbo(MboSet.java:1289)
at psdi.mbo.MboSet.isEmpty(MboSet.java:2726)
at psdi.jsp.beans.MboSetBean.isEmpty(MboSetBean.java:2843)
at psdi.jsptags.InputTagSupport.gridTagSupportWriter(InputTagSupport.java:403)
at psdi.jsptags.GridTagSupport.doEndTag(GridTagSupport.java:295)
at jsp_servlet._jsp._app._location.__main._jspService(__main.java:1392)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:2546)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2260)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)

6 replies

by josef.scherer

Hi

Could you submit some code, s.t. someone can judge, whether one of the Location objects is null?

Josef

by sbockelman

The error is caused by an attempt to access a property or call a method on an object reference that does not currently point to any valid object instance. This error is in the source code on line 604 of the file, Location.java.

How do I know this?
And why can't I tell you more?

1. That's exactly what the stack-trace/error message you included says.

2. You didn't include enough information to solve the problem.

I suggest asking a Java developer at your location to help you debug the JSP page that is failing.

by georgehsnyder

if you go to line 604 of Location.java you will probably find a loop (for or while). You appear to be trying to process beyond the end of your data array. Maybe you did not initialize it to a large enough size or you are up against the old 'off by one' problem. Create a DEBUG class that opens a file and writes your data into it. Pass each element of your data into the debug class then look at the file to see where things are going bad.

by debuggist

Obviously, you're trying to access something that is null. Could you supply the source code that is throwing the exception?

Do you have the source code for psdi.app.location.Location?

by ms_anand_babu

Probably u might've used a select query and tried to display the query results. U would've accessed the recordset when there is nothing returned to it out of execution of the query. Query result may be nothing.

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