高手请进jasperreport的异常问题在线等答案

2009-9-11 15:58:50 org.apache.catalina.core.StandardWrapperValve invoke 
严重: Servlet.service() for servlet action threw exception 
java.lang.NullPointerException 
at net.sf.jasperreports.engine.JRPropertiesMap.readObject(JRPropertiesMap.java:185) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) 
at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1667) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1323) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) 
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) 
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) 
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) 
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) 
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) 
at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:88) 
at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:64) 
at cn.com.infolink.rirm.report.actions.TrendsReport.trendsOrg(TrendsReport.java:112) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:269) 
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:170) 
at org.apache.struts.chain.commands.servlet.ExecuteAction.execute(ExecuteAction.java:58) 
at org.apache.struts.chain.commands.AbstractExecuteAction.execute(AbstractExecuteAction.java:67) 
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51) 
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191) 
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305) 
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191) 
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283) 
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913) 
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
at cn.com.infolink.rirm.encodingFilter.ActionEncodingFilter.doFilter(ActionEncodingFilter.java:24) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) 
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) 
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849) 
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) 
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454) 
at java.lang.Thread.run(Thread.java:619) JasperReport jasperReport = (JasperReport) JRLoader.loadObject(fileName); 
创建这个对象的时候就出错了！出了这个异常我看不懂 看了很久了！高手们帮个忙！