3 Replies Latest reply on Sep 12, 2007 3:29 AM by jamesjmp

servlet accessing seam components

jamesjmp Sep 11, 2007 12:32 PM

Hello,
I have problems trying to use a query from a servlet.
I´ve defined the following query in componentes.xml

 <framework:entity-query name="QueryJMP"
 ejbql="select jmp from Jmp jmp">
 </framework:entity-query>

On the other hand I´ve defined this servlet in my web.xml

 <servlet>
 <servlet-name>LogicServlet</servlet-name>
 <servlet-class>mypackage.LogicServlet</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>LogicServlet</servlet-name>
 <url-pattern>/download/*</url-pattern>
 </servlet-mapping>

I want to invoke a seam component (an entityquery or a java seam component) from LogicServlet. I´ve read in the seam reference that filter is needed to allow custom servlets to interact with the Seam contexts. So I´ve defined this filter in components.xml

<web:context-filter url-pattern="/download/*"/>

In the servlet I try to use the query this way:

public class LogicServlet extends HttpServlet {

 @In("#{QueryJMP.resultList}")
 List<Jmp> jmpList;

 ..

 public void doGet(HttpServletRequest req, HttpServletResponse res)
 throws ServletException, IOException {

 Iterator<Jmp> jmpIter = jmpList.iterator();

 if ((jmpIter != null) && (jmpIter.hasNext()) ) {
 ...
 }

Servlet invocation :

http://localhost:8080/JMP_ONLINE/download

But, when I try to use the query from the servlet it doesn´t work and generates this exceptions:

18:13:53,453 INFO [STDOUT] generando Iterator!!
18:13:53,906 ERROR [ExceptionFilter] uncaught exception
java.lang.NullPointerException
at es.rbcdexia.risk.servlet.FileViewer.doGet(FileViewer.java:84)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:63)
at org.jboss.seam.debug.hot.HotDeployFilter.doFilter(HotDeployFilter.java:60)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:57)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ContextFilter.doFilter(ContextFilter.java:56)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84)
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:96)
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.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
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:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
at java.lang.Thread.run(Thread.java:595)
18:13:53,937 ERROR [DebugPageHandler] redirecting to debug page
java.lang.NullPointerException
at es.rbcdexia.risk.servlet.FileViewer.doGet(FileViewer.java:84)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:63)
at org.jboss.seam.debug.hot.HotDeployFilter.doFilter(HotDeployFilter.java:60)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:57)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ContextFilter.doFilter(ContextFilter.java:56)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
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:595)
18:13:54,421 ERROR [ContextFilter] ended request due to exception
javax.servlet.ServletException: String index out of range: -1
at org.jboss.seam.web.ExceptionFilter.endWebRequestAfterException(ExceptionFilter.java:103)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:73)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ContextFilter.doFilter(ContextFilter.java:56)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
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:595)
18:13:54,921 ERROR [[LogicServlet]] Servlet.service() for servlet LogicServlet threw exception
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1762)
at java.lang.String.substring(String.java:1735)
at org.jboss.seam.mock.MockViewHandler.getActionURL(MockViewHandler.java:41)
at org.jboss.seam.core.Manager.redirect(Manager.java:1054)
at org.jboss.seam.core.Redirect.execute(Redirect.java:137)
at org.jboss.seam.exceptions.DebugPageHandler.handle(DebugPageHandler.java:29)
at org.jboss.seam.core.Exceptions.handle(Exceptions.java:79)
at org.jboss.seam.web.ExceptionFilter.endWebRequestAfterException(ExceptionFilter.java:91)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:73)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.ContextFilter.doFilter(ContextFilter.java:56)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:79)
at org.jboss.seam.web.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:49)
at org.jboss.seam.web.SeamFilter.doFilter(SeamFilter.java:84)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
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:595)

if I try to access to a POJO from the servlet there is the same problem.
In that case the code is

 @In(value="myPOJOName", create=true)
 POJOApp myPojo;

 ..
 myPojo.method(); //it fails here.....

I´ve used the same query and access to myPOJOName in other places of my application and they work ok.
I guess the problem is something related with configuration that prevents my servlet to interact with the seam context
thanks in advance!

1. Re: servlet accessing seam components

christian.bauer Sep 11, 2007 12:38 PM (in response to jamesjmp)

Servlets are not proxied, hence, no injection is happening. You need to do a lookup in the Seam contexts, see Component.getInstance().
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2. Re: servlet accessing seam components

trickyvail Sep 11, 2007 12:47 PM (in response to jamesjmp)

There is a servlet that does this in the seamspace example application. Take a look at ContentServlet.java.
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3. Re: servlet accessing seam components

jamesjmp Sep 12, 2007 3:29 AM (in response to jamesjmp)

thank you very much! getInstance was what I needed and that example is a really useful one for this!
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