用java實現文件下載，提示java.lang.IllegalStateException: getOutputStream() has already been called for this re

1、 用java實現文件下載，提示java.lang.IllegalStateException: getOutputStream() has already been called for this ...

java.lang.IllegalStateException: getOutputStream() has already been called for this respons 簡單解決辦法

今天在使用struts2 進行文件下載是，總報錯： java.lang.IllegalStateException: getOutputStream() has already been calle ...