目录

• 一、 Ajax
• 1.1 Ajax介绍
•  1.2 异步的作用
•  二、SpringBoot应用Ajax
• 2.1 开发配置
•  2.2 创建user表 
• 2.3 MVC三层架构
• 2.4 前端测试页面
• 2.5 测试结果
• 总结

一、 Ajax

1.1 Ajax介绍

AJAX 是一种在无需重新加载整个网页的情况下，能够更新部分网页的技术。

AJAX = 异步 JavaScript 和 XML

AJAX 是一种用于创建快速动态网页的技术。通过在后台与服务器进行少量数据交换，可以使网页实现异步更新。这意味着可以在不重新加载整个网页的情况下，对网页的某部分进行更新。传统的网页（不使用 AJAX）如果需要更新内容，必需重载整个网页面。

AJAX即Asynchronous JavaScript and XML（异步JavaScript和XML），是实现客户端和服务器异步通信的方法；同步：请求和页面的跳转同时发生；异步：请求和页面的跳转不同时发生；异步的请求可以实现页面的局部刷新；

 1.2 异步的作用

节省流量；无需刷新整个页面,服务器压力也降低；用户体验好；

 二、SpringBoot应用Ajax

2.1 开发配置

IDEA项目目录

pom.xml配置 

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>
 
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.8</version>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

application.yml

# 应用名称
spring:
  application:
    name: springboot-ajax
  # thymeleaf模板
  thymeleaf:
    cache: true
    check-template: true
    check-template-location: true
    enabled: true
    encoding: UTF-8
    mode: HTML5
    prefix: classpath:/templates/
    suffix: .html
 
# 数据源
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ajax?serverTimezone=UTC
    username: root
    password: 1234
    type: com.alibaba.druid.pool.DruidDataSource
 
# 应用服务 WEB 访问端口
server:
  port: 8080
 
mybatis:
  configuration:
    map-underscore-to-camel-case: true
 
 

 2.2 创建user表 

SQL实现

drop table if exists user;
create table user(
id int(8) NOT NULL AUTO_INCREMENT,
loginName varchar(30) NULL DEFAULT NULL,
loginPwd varchar(20) NULL DEFAULT NULL,
realName varchar(30) NULL DEFAULT NULL,
PRIMARY KEY(id) USING BTREE
)ENGINE=INNODB AUTO_INCREMENT=3 ROW_FORMAT=Dynamic;
 
insert into user values(1,'XiaoChen,'123456','小陈');
insert into user values(2,'XiaoWang','123456','小王');
insert into user values(3,'XiaoHua','123456','小花');

2.3 MVC三层架构

1）Entity实体类

user对象

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class User {
    private int id;
    private String loginName;
    private String loginPwd;
    private String realName;
}

mapper接口

@Mapper
@Repository
public interface UserMapper {
    @Select("select * from user")
    public List<User> queryUsers();
}

2) Service业务层

service层

public interface UserService {
    public List<User> queryAllUsers();
}

serviceImpl层

@Service
public class UserServiceImpl implements UserService {
    @Resource
    private UserMapper userMapper;
 
    @Override
    public List<User> queryAllUsers() {
        return userMapper.queryUsers();
    }
}

3）Controller层

@RestController
@CrossOrigin //解决跨域问题
public class UserController {
    @Resource
    private UserServiceImpl userServiceImpl;
 
    @RequestMapping("/xiaoChen")
    public String index(String name,String pwd){
        String msg="";
        List<User> users=userServiceImpl.queryAllUsers();
        User myUser=null;
        for(User user:users){
            if(user.getLoginName().equals(name)){
                myUser=user;
                msg="OK";
                break;
            }else{
                msg="账号错误";
            }
        }
        if(pwd!=null){
            if(myUser!=null&&myUser.getLoginPwd().equals(pwd)){
                msg="OK";
            }else{
                msg="密码错误";
            }
        }
        return msg;
    }
}

2.4 前端测试页面

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Ajax登录页面</title>
    <script src="/js/jquery-3.6.0.min.js"></script>
</head>
<body>
    <p>
        账号：<input type="text" id="name" onblur="test1()"/>
        <span id="username"></span>
    </p>
    <p>
        密码：<input type="text" id="pwd" onblur="test2()"/>
        <span id="userpwd"></span>
    </p>
    <script type="text/javascript">
        function test1(){
            $.post({
                url:"http://localhost:8080/xiaoChen",
                data:{'name':$("#name").val()},
                success:function(data){
                    if(data.toString()=='OK'){
                        $("#username").css("color","green");
                    }else{
                        $("#username").css("color","red");
                    }
                    $("#username").html(data);
                }
            });
        }
        function test2(){
            $.post({
                url: "http://localhost:8080/xiaoChen",
                data: {'pwd': $("#pwd").val()},
                success: function (data) {
                    if (data.toString()=='OK') {
                        $("#userpwd").css("color", "green");
                    } else {
                        $("#userpwd").css("color", "red");
                    }
                    $("#userpwd").html(data);
                }
            });
        }
    </script>
</body>
</html>

2.5 测试结果

总结