Hi,
With Tomcat 8.5.12 I hit a NPE when I use RequestDispatcher to redirect
from a servlet to another one in the case of the mapping of this second
servlet ends with /*. An error 500 is returned because of a
NullPointerException :
java.lang.NullPointerException
at
org.apache.catalina.core.ApplicationMapping.getServletMapping(ApplicationMapping.java:62)
at
org.apache.catalina.core.ApplicationContext.getRequestDispatcher(ApplicationContext.java:486)
at
org.apache.catalina.core.ApplicationContextFacade.getRequestDispatcher(ApplicationContextFacade.java:222)
at org.exoplatform.RedirectServlet.doGet(RedirectServlet.java:19)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
at
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1441)
at
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1161)
at
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:844)
To reproduce this issue I created a simple war with the following web.xml :
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd";
version="3.1"
metadata-complete="true">
<description>
Servlet and JSP Examples.
</description>
<display-name>Servlet and JSP Examples</display-name>
<servlet>
<servlet-name>HelloWorldExample</servlet-name>
<servlet-class>org.sample.HelloWorldServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>RedirectServlet</servlet-name>
<servlet-class>org.sample.RedirectServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldExample</servlet-name>
<url-pattern>/HelloWorldExample/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>RedirectServlet</servlet-name>
<url-pattern>/RedirectServlet</url-pattern>
</servlet-mapping>
</web-app>
The class RedirectServlet is :
package org.sample;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class RedirectServlet extends HttpServlet {
@Override
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
RequestDispatcher requestDispatcher =
request.getServletContext().getRequestDispatcher("/HelloWorldExample");
requestDispatcher.forward(request, response);
}
}
And the class HelloWorldServlet is :
package org.sample;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
public class HelloWorldServlet extends HttpServlet {
@Override
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE html><html>");
out.println("<head>");
out.println("<meta charset=\"UTF-8\" />");
out.println("<title>Hello World</title>");
out.println("</head>");
out.println("<body bgcolor=\"white\">");
out.println("<a href=\"../helloworld.html\">");
out.println("<img src=\"../images/code.gif\" height=24 " +
"width=24 align=right border=0 alt=\"view code\"></a>");
out.println("<a href=\"../index.html\">");
out.println("<img src=\"../images/return.gif\" height=24 " +
"width=24 align=right border=0 alt=\"return\"></a>");
out.println("<h1>Hello World !</h1>");
out.println("</body>");
out.println("</html>");
}
}
I do not have this issue with Tomcat 8.5.11.
I also do not have this issue if I change the mapping of the servlet
HelloWorldExample to "/HelloWorldExample" instead of "/HelloWorldExample/*".
It looks like a bug but I wanted to be sure of that before opening an issue
in the bugtracker. Should I open one ?
Thanks
