json解析报错java.lang.IllegalStateException，求指点啊

0 0

json解析报错java.lang.IllegalStateException，求指点啊0

public String getJson(){
		HttpServletResponse response=ServletActionContext.getResponse();
		response.setCharacterEncoding("utf-8");
		JSONArray jsonArray =null;
		PrintWriter out=null;
		try {
			out=response.getWriter();
			List<Student> list=studentList();
			System.out.println("===");
			jsonArray = JSONArray.fromObject(list);
			System.out.println("jsonArray");
			out.print(jsonArray);
			out.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			out.close();
		}
		return null;
	}

总是报这个错误，什么情况啊

java.lang.IllegalStateException
	at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:407)
	at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:839)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:533)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
	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:230)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
	at java.lang.Thread.run(Thread.java:619)

问题补充：我用的是struts2.3.1和json包及相关的包，这个会影响这个东东吗？