Question

I’am working on a rather old web application that incorporates the following technologies.

• SUN JSF RI 1.1
• facelets-api 1.1.14
• JBOSS 4.0.2
• Quipukit 1.6 (An AJAX JSF
  component library)

The application was originally developed with JSP renderer. For a new feature that will be added soon, we would like to switch to facelets, but we cant’t rewrite the rest, so we’ll have to run facelets and JSP rendering in parallel. Generally this works, but on some occasion (not reproducable) we get the following exception on the JSP parts of the application.

    15:34:45,995 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/].[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
java.lang.IllegalStateException: getWriter() has already been called for this response
    at org.apache.catalina.connector.Response.getOutputStream(Response.java:565)
    at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:171)
    at teamdev.jsf.util.ResourceFilter.doFilter(SourceFile:87)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
    at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39)
    at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:153)
    at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
    at java.lang.Thread.run(Thread.java:619)

When the Exception occurs it causes some weird behaviour, like values aren’t correctly submitted on the next action (obviously JSF phase have not been processed properly)

Here are the relevant parts from my web.xml and faces.config

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    version="2.4"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee   http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">


        <context-param>
            <param-name>javax.faces.CONFIG_FILES</param-name>
            <param-value>/WEB-INF/faces-config.xml</param-value>
        </context-param>


        <context-param>
            <param-name>javax.faces.DEFAULT_SUFFIX</param-name>
            <param-value>.jsp</param-value>
        </context-param>

        <!-- Use Documents Saved as *.xhtml -->
        <context-param>
            <param-name>facelets.VIEW_MAPPINGS</param-name>
            <param-value>*.xhtml</param-value>
        </context-param>

        <servlet>
            <servlet-name>Faces Servlet</servlet-name>
            <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
            <init-param>
                <param-name>config</param-name>
                <param-value>/WEB-INF/faces-config.xml</param-value>
            </init-param>
            <init-param>
                <param-name>debug</param-name>
                <param-value>3</param-value>
            </init-param>
            <init-param>
                <param-name>detail</param-name>
                <param-value>3</param-value>
            </init-param>
            <load-on-startup>0</load-on-startup>
        </servlet>

        <servlet-mapping>
            <servlet-name>Faces Servlet</servlet-name>
            <url-pattern>/faces/*</url-pattern>
        </servlet-mapping>

        <session-config>
            <session-timeout>60</session-timeout>
        </session-config>

        <welcome-file-list>
            <welcome-file>index.jsp</welcome-file>
        </welcome-file-list>







<faces-config>
    <application>
        <message-bundle>validatormessages</message-bundle>
        <locale-config>
            <default-locale>de_DE</default-locale>
            <supported-locale>en_GB</supported-locale>
            <supported-locale>en_US</supported-locale>
            <supported-locale>fr_FR</supported-locale>
        </locale-config>
        <view-handler>com.sun.facelets.FaceletViewHandler</view-handler>
    </application>

...

</faces-config>

Any help ist appreciated.

Regards

Answer 1

JSP will call getWriter() when it’s using scriptlet expressions (<%= %>) or when you’re explicitly writing to output by out.print in a scriptlet (<% %>).

Verify if you don’t have any of such things in your JSP pages.