ajax获取json怎么写,ajax小白

将resultset转为json,html用ajax获取json数据并显示
完全没有思路 求解答

@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

    Connection conn = DBConnectUtils.getConnection();
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    // json数组
    JSONArray array = new JSONArray();
    try {
        String sql = "select id,username from User";
        System.out.println(sql);
        pstmt = conn.prepareStatement(sql);
        rs = pstmt.executeQuery();
        // 获取列数
        ResultSetMetaData metaData = rs.getMetaData();
        int columnCount = metaData.getColumnCount();
        // 遍历ResultSet中的每条数据
        while (rs.next()) {
            JSONObject jsonObj = new JSONObject();
            // 遍历每一列
            for (int i = 1; i <= columnCount; i++) {
                String columnName = metaData.getColumnLabel(i);
                String value = rs.getString(columnName);
                jsonObj.put(columnName, value);
                System.out.println(jsonObj);
                System.out.println("----------------------------");
            }
            array.add(jsonObj);
        }

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        DBCloseUtils.closeCSR(conn, pstmt, rs);
    }
}

我项目里的一个例子,可以参考一下
后台部分:

   @RequestMapping("counselorList")
    public void counselorList(HttpServletResponse response) throws Exception {

        List<EcCustomer> counselorList = new ArrayList<EcCustomer>();
        List<String> list = new ArrayList<>();
        counselorList = ecCustomerSV.counselorList();
        for (int i = 0; i < counselorList.size(); i++) {
            list.add(i, counselorList.get(i).getPerson_in_charge_name());
        }
        String jsonText = JSON.toJSONString(list, true);
        response.getWriter().write(jsonText);
        System.out.println(jsonText);
    }

js部分:

  $(function () {
                $.ajax({
                    type: "POST",
                    async: false,
                    url: _CTX + '/ecCustomer/counselorList',
                    contentType: "application/json; charset=utf-8",
                    data: "{}",//没有参数的初始化
                    dataType: "json",
                    success: function (counselorList) {
                        list = counselorList;
                    },
                    error: function (err) {
                        alert("error:" + err);
                    }
                })
            })
 $.ajax({
                    url:'url',
                    type:'post',
                    success:function(data){
                        data = eval("("+data+")");
                        console.log(data.**result**);//result就是你的json属性名字
                    }

                });

http://blog.csdn.net/thl331860203/article/details/7288579

                    url:"/demo4/userdata/login/save",
                    type:"post",
                    data:sendData,
                    dataType:"json",
                    success:function(msg){
                        if (msg.error_num==0) {
                            location.href="/demo4/user/checked"
                        } else {
                            alert("登录失败,"+msg.error_msg);
                        }
                    },
                    error:function(a,b,c){
                        alert(c);
                    }
                })

$.ajax({
url:'地址',
type:'方式',
success:function(data){
data(这里的data就是你获取到的数据,可以根据你JSON文件里的属性来分别获取具体的值如:data.name[1]name属性的第二个值)
(然后将值赋值给你的变量就可以了,也可以直接运用。如:$("#content").html(data.content)

                }
                                    error:function(){
                                    连接失败返回的。
                                    }

}