java.lang.IllegalStateException: getWriter() has already been called for this response

出现原因：

1.代码中有打开的Response.getWriter()，未关闭

2.再次使用了ServletOutputStream out = response.getOutputStream();

通过查看代码，response中的usingWriter=true，想办法将该标志位设置为false。

response.reset(); 即可

扩展：OutputStream和Writer在一个response中不能同时获得。

本文出自 “javaruler” 博客，请务必保留此出处http://tengjs.blog.51cto.com/5641106/1582109

java.lang.IllegalStateException: getWriter() has already been called for this response