JQ實現ajax簡單代碼

這裏是 html頁面jq代碼

		$("#btn").click(function() {
		$.ajax({
			url: "http://localhost:8080/FirstServlet/Register", 
			method: "get",
			data:{
				"username":$("#name").val(),
				"pwd":$("#password").val()
			},
			success: function(data) {
			    console.log(data)
			    var resultObj = JSON.parse(data)
			    console.log(resultObj)
			    console.log("resultObj.msg:" + resultObj.msg)
			    console.log("resultObj.code:" + resultObj.errcode)
			    if (resultObj.code == 0) {
			    	alert(resultObj.msg)
			    } else {
			    	var spanItem = $("<span style='color:red'>error</span>");
			    	$("#name-group").append(spanItem)
			    }
			}
		});
	});

下面是servlet中的簡單實現

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	    response.setContentType("text/html;charset=UTF-8");
	    String username = request.getParameter("username");
        String pwd = request.getParameter("pwd");
        UserDao userDao = new UserDao();
        List<User> findByName = new ArrayList<>();
        try {
            Map map = new HashMap<>();
            findByName = userDao.findByName(username);
            if (findByName.size() != 0) {
                map.put("code", 1);
                map.put("msg", "用戶名已存在");
                map.put("data", null);
                
            } else {
                userDao.regsiter(username, pwd);
                map.put("code", 0);
                map.put("msg", "success");
                map.put("data", null);
            }
            String jsonString = JSON.toJSONString(map);
            response.getWriter().append(jsonString);
            response.getWriter().close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
	}