I have a web app consisting of some JSPs that were previously running on a Linux box. I need to get this running on a Windows XP SP3 machine running Tomcat 5.5.29. Most everything is working now but this one item: The app has a capability to write a configuration file to its Windows directory (i.e. C:\Program Files\Apache\Tomcat\webapps\myapp). But when it tries to do this, the app cannot open the FileOutputStream (returns null). If I drop off the path specifier, and just let it open the file, it successfully opens it in the Tomcat directory.
The first line fails, but the second one succeeds:
// outputFile2 = new PrintWriter(new FileOutputStream(basePathName + "programAll.txt", false));
outputFile2 = new PrintWriter(new FileOutputStream("programAll.txt", false));
Here is the code that creates the basePathName:
String basePathName = getBaseFilePath();
...
public String getBaseFilePath()
{
String curDir = System.getProperty("catalina.home");
curDir = curDir + "/webapps/pubmed/";
curDir = "file:///" + formatPathNameForOS(curDir);
return curDir;
}
public String formatPathNameForOS(String pathName)
{
if (codeIsOnWindows())
{
pathName = pathName.replace('/','\\');
}
else
{
pathName = pathName.replace('\\','/');
}
return pathName;
}
Here’s the exception message:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause
java.lang.NullPointerException
org.apache.jsp.updateMemberLists_jsp._jspService(updateMemberLists_jsp.java:1492)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
Here’s the stack trace:
Aug 6, 2010 1:20:39 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.updateMemberLists_jsp._jspService(updateMemberLists_jsp.java:1492)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.globus.tomcat.coyote.valves.HTTPSValve55.invoke(HTTPSValve55.java:45)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:873)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:595)
I’ve looked at the updateMembersLists_jsp.java, and here is the section where the null pointer is occurring:
//create a file to write to the output
PrintWriter outputFile2 = null;
try
{
outputFile2 = new PrintWriter(new FileOutputStream(basePathName + "programAll.txt", false));
// outputFile2 = new PrintWriter(new FileOutputStream("programAll.txt", false));
}
catch (FileNotFoundException e)
{
out.write("<p><font color='red'>Error Saving</font></p>");
}
outputFile2.print(output); // THIS IS LINE 1492 -- NULL POINTER
outputFile2.close();
Also: We are now running Tomcat off of the root directory instead of Program Files. I have checked the basePathName and it is being calculated correctly.
Now I figured out that Tomcat’s policy settings might need to be adjusted. I added the following lines to catalina.policy hoping it would set things right:
// The permissions granted to the pubmed webapp
grant codeBase "file:${catalina.home}/webapps/pubmed/-" {
permission java.io.FilePermission "${catalina.home}/webapps/pubmed/-", "read, write";
permission java.io.FilePermission "${catalina.home}/webapps/pubmed/*", "read, write";
};
This didn’t seem to have any effect. The Windows user that tomcat is running under has read/write permissions on the pubmed directory. Aside from the fact that it seems questionable for this webapp to be writing files to its own directory, what am I missing?
Sean
Try obtaining the path in the following way:
This will convert your path (to your webapp) to the actual path on your disk.