java.lang.OutOfMemoryError: Java heap space

[irs_bandari]

Hi
I am writing an application in struts for file downloading from the database. I am using struts 1.1 with tomcat5.0 server. File downloading is working fine for images of smaller sizes( i checked utpo 3mb of size). my application should download the files with a maximum 1gb size. But when I tried to download the image of 85mb, "out of memory" exception is thrown" and this is the complete trace of that exception...

Oct 19, 2006 4:11:35 PM org.apache.struts.actions.DispatchAction dispatchMethod
SEVERE: Dispatch[/pages/DoctorModule/medicalrecord/frame/referencedoc] to method getReportFormat returned an exception
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:280)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:216)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:480)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process (ActionServlet.java:1420)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:520)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service (HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java :157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke (StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke (StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke (StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java :799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.jav a:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run (ThreadPool.java:683)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.OutOfMemoryError: Java heap space
Oct 19, 2006 4:11:35 PM org.apache.struts.action.RequestProcessor processException
WARNING: Unhandled Exception thrown: class java.lang.IllegalStateException

I checked using downloading action example from struts1.2.6, even thats giving the same out of memory exception. Any how my application uses only 1.1. so Please give me some solution for this exception..