The request associated with the AsyncContext has already completed processing.处理

前段时间在用servlet3.0时出现了一个问题，就是在servlet在异步处理数据时，由于时间超时，索然方法执行结束，但是后台抛出了异常，异常如下：

java.lang.IllegalStateException: The request associated with the AsyncContext has already completed processing.  
     at org.apache.catalina.core.AsyncContextImpl.check(AsyncContextImpl.java:521)  
     at org.apache.catalina.core.AsyncContextImpl.getResponse(AsyncContextImpl.java:245)  

 出现这个的原因是因为servlet默认的异步处理时间为10秒，显然由于数据量过大，导致时间超时。

解决办法也很简单只需要在servlet的doPost方法中加入一下一句

 asyncContext.setTimeout(900000000);

 为异步加载手动的设置超时时间即可，全部代码如下：

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");
        response.setContentType(getServletContext().getInitParameter("content"));	
		//进入异步模式,调用业务处理线程进行业务处理
        //Servlet不会被阻塞,而是直接往下执行
        //业务处理完成后的回应由AsyncContext管理
        AsyncContext asyncContext = request.startAsync();
        asyncContext.setTimeout(900000000);
        ProductHandleThread productHandleThread = new ProductHandleThread(asyncContext,request.getSession());
        asyncContext.start(productHandleThread);
	}