这篇文章主要为大家详细介绍了Ajax实现登录案例，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下
Ajax登录案例，供大家参考，具体内容如下Msgpackage com.lbl.msg;public class Msg {String msg;
int code; public Msg() {
} public Msg(String msg, int code) {
this.msg = msg;
this.code = code;
} public String getMsg() {
return msg;
} public void setMsg(String msg) {
this.msg = msg;
} public int getCode() {
return code;
} public void setCode(int code) {
this.code = code;
}
}RegisterServletpackage com.lbl.servlet;import com.fasterxml.jackson.databind.ObjectMapper;
import com.lbl.msg.Msg;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;@WebServlet("/register")
public class RegisterServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
} protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1:获取请求发送的数据
String username = request.getParameter("username");
response.setContentType("text/html;charset=UTF-8");
//2:判断用户名是否注册
if("abc123".equals(username)){
Msg msg = new Msg("用户名已经注册",0);
//用户名已经注册 {"flag":false,"info":"用户名已经注册"};
// String jsonStr = "{\"flag\":false,\"info\":\"用户名已经注册\"}";
//响应回浏览器
response.getWriter().write(new ObjectMapper().writeValueAsString(msg));
}else{
Msg msg = new Msg("可以注册",1);
//用户名没有注册
// String jsonStr = "{\"flag\":true,\"info\":\"可以注册\"}";
//响应回浏览器
response.getWriter().write(new ObjectMapper().writeValueAsString(msg));
} }
}json_register.html<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<ｓｃｒｉｐｔ src="js/jquery-3.3.1.js"></ｓｃｒｉｐｔ>
<ｓｃｒｉｐｔ type="application/javascript">
$(function () {
//1: 给用户名输入框绑定失去焦点事件(onfocus onblur)
$("#username").on("blur",function () {
//获取用户名输入框数据
var username = $("#username").val();
//2:向服务器发出异步请求，让服务器去查询用户名是否存在
$.post(
"register", //表示服务器的servlet路径
"username="+username, //表示向服务器发送的数据
function (data) { // msg:用户名已经注册 code:0
if(data.code==0){
// alert(data.info);
$("#spanId").html(data.msg).css("color","green");
}else {
$("#spanId").html(data.msg).css("color","red");
} },
"json"
);
});
}); </ｓｃｒｉｐｔ>
</head>
<body>
<p>
<font>会员注册</font>USER REGISTER
<formstyle="margin-top: 5px;">
<table>
<tr>
<td>用户名</td>
<td>
<input type="text"name="username" placeholder="请输入用户名">
<span ></span>
</td>
</tr>
<tr>
<td>密码</td>
<td>
<input type="password" placeholder="请输入密码">
</td>
</tr>
</table>
<input type="submit" value="注册"/>
</form>
</p></body>
</html>来源：本站链接：https://www.jb51.net/article/196051.htm
