ajax获取json怎么写，ajax小白

Question

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);
    }
}

Answer 1

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);
                    }
                })
            })