repeated doGet call

Question

My snippet of HttpServlet:

   protected void doGet(HttpServletRequest httpServletRequest,
                         HttpServletResponse httpServletResponse) throws ServletException,
                                                                         IOException {
        final String[] values = httpServletRequest.getParameterValues("p");
        final int p;
        if (values != null && values.length > 0) {
            p = Integer.parseInt(values[0]);
        } else {
            p = 0;
        }
        final ServletContext context = super.getServletContext();
        switch (p) {
        case 0:
            {

                final CityRepresentationBean bean =
                    new CityRepresentationBean(ds);
                final RequestDispatcher rqDsp;
                try {
                    rqDsp =
                            context.getRequestDispatcher(bean.act(httpServletRequest));
                    rqDsp.forward(httpServletRequest, httpServletResponse);
                } catch (ConnectionException e) {
                    throw new ServletException(e);
                }
 ......
}

The main problem is that I get StackOverFlow Exception. From Debug I have found that I get ConnectionException then method doGet is called again (I even don't have a clue who can call it) after throw new ServletException(e).

The question is How the servlet can be called several time if browser invokes URL only once?

java.lang.StackOverflowError
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:303)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
    at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:523)
    at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
    at project2.FrontController.doGet(FrontController.java:64)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
    at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:523)
    at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
    at project2.FrontController.doGet(FrontController.java:64)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
    at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:523)
    at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
    at project2.FrontController.doGet(FrontController.java:64)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
    at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:523)
    at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
    at project2.FrontController.doGet(FrontController.java:64)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:183)
    at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:523)
    at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:253)
    at project2.FrontController.doGet(FrontController.java:64)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)

Most likely one of the conditions maps back to the same servlet. — Dave Newton, Nov 11 '11 at 20:45

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

The URL pattern of that servlet is also been matched on the URL which is returned by bean.act(httpServletRequest) in your RequestDispatcher#forward().

So, you have 2 options:

Map the servlet on a more specific URL pattern. At least not on /* or something. For example, /pages/* or *.do.
Make sure that the URL returned by act() doesn't match the servlet's URL pattern.

repeated doGet call

1 Answers1

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