java.lang.IllegalStateException: getWriter， has already been called for this response问题解决

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

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

在执行下述代码时报错，

OutputStream out = getResponse().getOutputStream();

原因为代码中有打开的Response.getWriter()，未关闭，因调用点较多，不好一一排查。

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

response.reset(); 即可，注意reset后缓存消失，设置消失。

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