将请求的数据以json（plain）输出有乱码

由于发送一个请求路径返回到浏览器是一串json字符串，虽然写了过滤器但是实际上过滤器没有拦截到。因此它是一段纯文本格式，所有要设置它的编码类型和字符编码，

也就是response.setContentType("text/plain;charset=UTF-8")，但是它的设定一定要在pw.write(json)之前。否则还是会出现乱码。

public class BaseAction extends ActionSupport implements ServletRequestAware, ServletResponseAware{

 /**
  * @Fields serialVersionUID : 序列化
  */
 private static final long serialVersionUID = 2823334602737926536L;
 
 public static final String JSON_ERROR = "{\"success\":\"false\"}";
 public static final String JSON_SUCCESS = "{\"success\":\"true\"}";
 protected HttpServletRequest _request;
 protected HttpServletResponse _response;
 
 @Override
 public void setServletResponse(HttpServletResponse response) {
  this._response=response;
  this._response.setContentType("text/plain;charset=UTF-8");
 }

 @Override
 public void setServletRequest(HttpServletRequest request) {
  this._request=request;
 }
 @JSON(serialize=false)
 public void returnJson(String json){
  PrintWriter pw=null;
  try {
   pw=this._response.getWriter();
   pw.write(json);
   pw.flush();
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   if (pw!=null) {
    pw.close();
   }
  }
 } 
}