has already been called for this response

getWriter() has already been called for this response
 
PrintWriter out = response.getWriter();

OutputStream outputStream = response.getOutputStream();  

 

response重复调用！删除一个即可
如果想继续调用，下面再重设

response.reset();

 

PrintWriter out = response.getWriter();

 

response.setContentType(String);