问题
While clicking on the Preview button or running the report in the web viewer Following ERROR is arising.
org.eclipse.birt.report.presentation.aggregation.layout.RunFragment cannot be cast to org.eclipse.birt.report.presentation.aggregation.IFragment
Caused by:
java.lang.ClassCastException: org.eclipse.birt.report.presentation.aggregation.layout.RunFragment cannot be cast to org.eclipse.birt.report.presentation.aggregation.IFragment at org.apache.jsp.webcontent.birt.pages.layout.RunFragment_jsp._jspService(RunFragment_jsp.java:63) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.equinox.jsp.jasper.JspServlet.service(JspServlet.java:112) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180) at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90) at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111) at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:75) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.equinox.http.jetty.internal.HttpServerManager$InternalHttpServiceServlet.service(HttpServerManager.java:318) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:380) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.servlet.Dispatcher.include(Dispatcher.java:192) at org.eclipse.equinox.http.servlet.internal.RequestDispatcherAdaptor.include(RequestDispatcherAdaptor.java:37) at org.eclipse.birt.report.presentation.aggregation.layout.FramesetFragment.service(FramesetFragment.java:98) at org.eclipse.birt.report.servlet.ViewerServlet.__doGet(ViewerServlet.java:181) at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.doGet(BirtSoapMessageDispatcherServlet.java:160) at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.service(BirtSoapMessageDispatcherServlet.java:122) at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180) at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90) at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111) at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:59) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.equinox.http.jetty.internal.HttpServerManager$InternalHttpServiceServlet.service(HttpServerManager.java:318) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:380) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:324) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:535) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:865) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:540) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:213) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:520)
What are the reasons behind it and its solutions
回答1:
The two classes come from different classloaders. One is probably from OSGi, the other from the classloader of your app or your app container.
Try to print the values of IFragment.class.getClassLoader() and RunFragment.class.getClassLoader() to see if they are the same. If not, clean up your classloaders :-)
Check out the FAQ and this (seemingly unrelated) FAQ item.
来源：https://stackoverflow.com/questions/3132186/eclipse-galileo-birt