java PrintWriter 返回的打印值乱码的问题

HttpServletResponse response = ServletActionContext.getResponse();

HttpServletRequest request = ServletActionContext.getRequest();

response.setCharacterEncoding("GBK");

response.setContentType("text/html; charset=GBK");

PrintWriter out = response.getWriter();

String jsonString = "如果不加上面标蓝部分两行代码，就会输出乱码";

out.add(jsonString);

out.flush();

out.close();

如果不加入标蓝部分的两行代码输出会是乱码，当然是GBK还是UTF-8就要你自己去定义了！