SpringBoot - MyBatis(注解) 连接MySql

叁歲伎倆 2022-05-29 02:46 146阅读 0赞

> 注解只是把mapper.xml 文件注到 mapper.calss 中，这个只是我自己的理解；

# 1、添加 Maven 依赖 #

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.2</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
        </dependencies>

# 2、配置属性文件（application.properties） #

spring.datasource.url=jdbc:mysql://localhost:3306/test
    spring.datasource.username=root
    spring.datasource.password=123456
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver

# 3、代码范例 #

User.java

package com.hsq.test3.bean;
    
    public class User { 
        private int id;
        private String name;
        private int age;
        private int sex;
    
        public User() {
        }
    
        public User(int id, String name, int age, int sex) {
            this.id = id;
            this.name = name;
            this.age = age;
            this.sex = sex;
        }
    
        public int getId() {
            return id;
        }
    
        public void setId(int id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public int getSex() {
            return sex;
        }
    
        public void setSex(int sex) {
            this.sex = sex;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", age=" + age +
                    ", sex=" + sex +
                    '}';
        }
    }

UserMapper.java

package com.hsq.test3.mapper;
    
    import com.hsq.test3.bean.User;
    import org.apache.ibatis.annotations.Mapper;
    import org.apache.ibatis.annotations.Select;
    import org.springframework.stereotype.Component;
    import java.util.List;
    
    @Mapper
    @Component
    public interface UserMapper { 
        @Select("select id,name,age,sex from users")
        List<User> findUser();
    // @Insert("insert into account(name, money) values(#{name}, #{money})")
    // int add(@Param("name") String name, @Param("money") double money);
    }

UserService.java

package com.hsq.test3.service;
    
    import com.hsq.test3.bean.User;
    import com.hsq.test3.mapper.UserMapper;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import java.util.List;
    
    @Service
    public class UserService { 
        @Autowired
        private UserMapper userMapper;
    
        public List<User> findUser(){
            return userMapper.findUser();
        }
    
    }

UserController.java

package com.hsq.test3.controller;
    
    import com.hsq.test3.bean.User;
    import com.hsq.test3.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import java.util.List;
    
    @RestController
    @RequestMapping()
    public class UserController { 
        @Autowired
        UserService userService;
        @GetMapping("/")
        public List<User> findUser(){
            return userService.findUser();
        }
    }

# 运行 #

启动项目，访问地址： [http://localhost:8080/getUser][http_localhost_8080_getUser]

结果如下：

[{
       "id":1,"name":"asdf","age":1,"sex":1},{
       "id":2,"name":"aswer","age":2,"sex":0},{
       "id":3,"name":"hty","age":3,"sex":1}]

[http_localhost_8080_getUser]: http://localhost:8080/getUser