JSONArray和JSONObject的详细使用：http://blog.csdn.net/yangbobo1992/article/details/8350765
　　/**     * ajax调用返回json数组     * @param list     */    public void printList(List<?> list){        HttpServletResponse response = ServletActionContext.getResponse();  //获取response实例        response.setContentType("text/html");　　　　　　//设置输出类型        response.setCharacterEncoding("UTF-8"); //设置输出编码                /*JsonConfigFactory.getInstance();        JSONArray jsonArray = new JSONArray();        jsonArray.addAll(list, JsonConfigFactory.getInstance());        */        try {            response.getWriter().print(JSONArray.fromObject(list, JsonConfigFactory.getInstance()));        } catch (IOException e) {            e.printStackTrace();        }    }        /**     * ajax调用返回json对象     * @param obj     */    public void printObject(Object obj){        HttpServletResponse response = ServletActionContext.getResponse();        response.setContentType("text/html");        response.setCharacterEncoding("UTF-8");        try {            response.getWriter().print(JSONObject.fromObject(obj,JsonConfigFactory.getInstance()));        } catch (IOException e) {            e.printStackTrace();        }    }        /**     * ajax调用返回json对象     * @param obj     */    public void printSting(String str){        HttpServletResponse response = ServletActionContext.getResponse();        response.setContentType("text/html");        response.setCharacterEncoding("UTF-8");        try {            response.getWriter().print(str);        } catch (IOException e) {            e.printStackTrace();        }