Error 500--Internal Server Error

java.lang.NullPointerException
	at jsp_servlet._xh._common._jsp.__filedownload._jspService(__filedownload.java:126)
	at weblogic.servlet.jsp.JspBase.service(JspBase.java:33)
	at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
	at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
	at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:28)
	at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:27)
	at com.xinhua.web.common.servlet.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:96)
	at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:27)
	at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6316)
	at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
	at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
	at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
	at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
	at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
	at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)