getWriter() exceptions when applet is loading

Question

I have a rather large applet (54,000 lines of code) that gives endless numbers of:

    java.lang.IllegalStateException: getWriter() has already been called for this response

-exceptions while the required applet libaries are being loaded. As best that I can tell, they are not being caused by my code directly. The page is JSF 2.2 xhtml running on Glassfish 4.1.

I am using the applet tag because the Object tag does not support percentage widths.

<applet code="org.appletinterface.CriteriaInterface.class" 
        archive="CriteriaInterfaceApplet.jar, lib/AbsoluteLayout.jar, lib/appframework-1.0.3.jar, lib/beansbinding-1.2.1.jar, lib/SearchCriteriaEditor.jar, lib/swing-worker-1.1.jar" 
        id="criteriaApplet"
        width="100%" 
        height="1600"
        centerimage="false"
        >
</applet>

The applet loads fine, but I would like to get rid of these errors before starting beta testing. Its spitting out 11,183 lines of these errors each time so its not something that can be easily ignored.

I am at the pointy end of launching a 4 year, 144,000 line project (I am the only programmer) and am running out of time before launch so any help would be greatly appreciated.

Update: by chance I was checking out another bug which was causing the applet to freeze momentarily. The problem was that setting the background on a jPanel was causing exactly the same two errors, in the second lot of errors listed below, to occur. There were that many errors being generated that it was causing the applet to freeze while they were being output to the Netbeans console. This jPanel had bindings to set the background colours of several other panels, so that I only had to set one panel's background colour.

Removing the bindings and manually changing the other panel's colours fixed the problem. Using a Try-Catch around setting the background colour did not trap any errors. I still have the errors when the applet loads however and am still investigating. Is there any other way of trapping an error, such as the background problem, which try catches are missing?

The initial errors generated when the applet begins loading is the following four times over:

        INFO:   Exception when handling error trying to reset the response.
    java.io.IOException: An existing connection was forcibly closed by the remote host
        at sun.nio.ch.SocketDispatcher.write0(Native Method)
        at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:51)
        at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93)
        at sun.nio.ch.IOUtil.write(IOUtil.java:51)
        at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:487)
        at org.glassfish.grizzly.nio.transport.TCPNIOUtils.flushByteBuffer(TCPNIOUtils.java:149)
        at org.glassfish.grizzly.nio.transport.TCPNIOUtils.writeCompositeBuffer(TCPNIOUtils.java:87)
        at org.glassfish.grizzly.nio.transport.TCPNIOAsyncQueueWriter.write0(TCPNIOAsyncQueueWriter.java:112)
        at org.glassfish.grizzly.nio.transport.TCPNIOAsyncQueueWriter.write0(TCPNIOAsyncQueueWriter.java:91)
        at org.glassfish.grizzly.nio.AbstractNIOAsyncQueueWriter.processAsync(AbstractNIOAsyncQueueWriter.java:333)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:108)
        at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
        at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
        at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.executeIoEvent(WorkerThreadIOStrategy.java:103)
        at org.glassfish.grizzly.strategies.AbstractIOStrategy.executeIoEvent(AbstractIOStrategy.java:89)
        at org.glassfish.grizzly.nio.SelectorRunner.iterateKeyEvents(SelectorRunner.java:414)
        at org.glassfish.grizzly.nio.SelectorRunner.iterateKeys(SelectorRunner.java:383)
        at org.glassfish.grizzly.nio.SelectorRunner.doSelect(SelectorRunner.java:347)
        at org.glassfish.grizzly.nio.SelectorRunner.run(SelectorRunner.java:278)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
        at java.lang.Thread.run(Thread.java:744)

The getWriter() errors then begin; these two can repeat up to 30 times over:

            WARNING:   Servlet.service() for servlet default threw exception
    java.lang.IllegalStateException: getWriter() has already been called for this response
        at org.apache.catalina.connector.Response.getOutputStream(Response.java:746)
        at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:206)
        at javax.servlet.ServletResponseWrapper.getOutputStream(ServletResponseWrapper.java:142)
        at org.apache.catalina.servlets.DefaultServlet.serveResource(DefaultServlet.java:1026)
        at org.apache.catalina.servlets.DefaultServlet.doGet(DefaultServlet.java:568)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at sun.reflect.GeneratedMethodAccessor1330.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:323)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:321)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAsPrivileged(Subject.java:536)
        at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:356)
        at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:214)
        at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1676)
        at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:875)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:739)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:695)
        at org.apache.catalina.core.ApplicationDispatcher.access$100(ApplicationDispatcher.java:98)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:201)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:190)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:618)
        at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:500)
        at org.apache.catalina.core.StandardHostValve.dispatchToErrorPage(StandardHostValve.java:699)
        at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:380)
        at org.apache.catalina.core.StandardHostValve.postInvoke(StandardHostValve.java:234)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:417)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
        at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
        at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
        at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
        at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
        at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
        at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
        at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
        at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
        at java.lang.Thread.run(Thread.java:744)

    WARNING:   org.apache.catalina.core.StandardHostValve@18bc551: Exception Processing ErrorPage[errorCode=404, location=/PageNotFoundRedirect.xhtml]
    java.lang.IllegalStateException: getWriter() has already been called for this response
        at org.apache.catalina.connector.Response.getOutputStream(Response.java:746)
        at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:206)
        at javax.servlet.ServletResponseWrapper.getOutputStream(ServletResponseWrapper.java:142)
        at org.apache.catalina.servlets.DefaultServlet.serveResource(DefaultServlet.java:1026)
        at org.apache.catalina.servlets.DefaultServlet.doGet(DefaultServlet.java:568)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at sun.reflect.GeneratedMethodAccessor1330.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:323)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:321)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAsPrivileged(Subject.java:536)
        at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:356)
        at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:214)
        at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1676)
        at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:875)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:739)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:695)
        at org.apache.catalina.core.ApplicationDispatcher.access$100(ApplicationDispatcher.java:98)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:201)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:190)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:618)
        at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:500)
        at org.apache.catalina.core.StandardHostValve.dispatchToErrorPage(StandardHostValve.java:699)
        at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:380)
        at org.apache.catalina.core.StandardHostValve.postInvoke(StandardHostValve.java:234)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:417)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
        at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
        at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
        at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
        at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
        at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
        at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
        at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
        at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
        at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
        at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
        at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
        at java.lang.Thread.run(Thread.java:744)

1st error says webbrowser has aborted the request (without a clear reason). 2nd error says server failed to show error page because it couldn't write the error page contents. 1st error seems unavoidable (this is simliar to Tomcat's dreaded [ClientAbortException](http://stackoverflow.com/q/9788891)), you could try suppressing it in a servlet filter. 2nd error could be avoided by suppressing the 1st error as explained, or by decent exception handling. — BalusC, Dec 19 '15 at 14:27
Many thanks BalusC, I am happy just to get rid of the errors for the moment; it makes finding more serious errors a pain, having to scroll through pages and pages of output all the time. — Robbie62, Dec 20 '15 at 12:34
Unfortunately the filter did not trap the error. The problem may be similar to a problem with setting the background color on a jPanel that had other panels bound to its background colour. I have updated the question — Robbie62, Dec 22 '15 at 05:50

getWriter() exceptions when applet is loading

0 Answers0