javaweb返回json對象

1.准備

　　json-lib-2.4-jdk15:這個第三方jar包(版本隨便,這里版本是2.4)

　　此外還需要額外json-lib所依賴的包json-lib-2.4-jdk15.jar所需全部JAR包.rar

2.設置頭部

    req.setCharacterEncoding("utf-8");
    resp.setCharacterEncoding("utf-8");
    resp.setHeader("content-type", "application/json;charset=utf-8");
    PrintWriter pw = resp.getWriter();
    JSONObject jo = new JSONObject();
    jo.put("status", 200);
    jo.put("msg", "訪問成功");
    pw.write(jo.toString());