SpringBoot - MyBatis 连接数据库

我就是我 2022-05-29 01:39 255阅读 0赞

> Spring Boot中集成MyBatis，可以选用基于注解的方式（下篇会介绍简单的使用），也可以选择xml文件配置的方式。通过对两者进行实际的使用，还是建议使用XML的方式（官方也建议使用XML）。下面将介绍通过xml的方式来实现查询；

# 1、添加 Maven 依赖 #

下面是所有需要的依赖，如果有依赖的话可以不加

<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>1.3.0</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
    
    mybatis.mapper-locations=classpath*:mapping/*Mapper.xml
    mybatis.type-aliases-package=com.hsq.test2.bean

# 3、代码范例 #

User.class 实体类

package com.hsq.test2.bean;
    
    public class User { 
        private int id;
        private String name;
        private int age;
        private int sex;
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", age=" + age +
                    ", sex=" + sex +
                    '}';
        }
    
        public User(int id, String name, int age, int sex) {
            this.id = id;
            this.name = name;
            this.age = age;
            this.sex = sex;
        }
    
        public User() {
        }
    
        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;
        }
    }

UserMapper.class

package com.hsq.test2.mapper;
    
    import com.hsq.test2.bean.User;
    import java.util.List;
    
    @Component
    public interface UserMapper { 
        List<User> findUser();
    }

UserMapper.xml（路径：src/main/resources/mapping/UserMapper.xml）

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.hsq.test2.mapper.UserMapper">
    
        <resultMap id="BaseResultMap" type="com.hsq.test2.bean.User">
            <id property="id" column="id" />
            <result property="name" column="name" />
            <result property="age" column="age" />
            <result property="sex" column="sex" />
        </resultMap>
    
        <select id="findUser" resultMap="BaseResultMap" resultType="com.hsq.test2.bean.User">
            SELECT id,name,age,sex FROM users
        </select>
    
    </mapper>

UserService.java

package com.hsq.test2.service;
    
    import com.hsq.test2.bean.User;
    import com.hsq.test2.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.class

package com.hsq.test2;
    
    import com.hsq.test2.bean.User;
    import com.hsq.test2.service.UserService;
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    import java.util.List;
    
    @RestController
    @MapperScan("com.hsq.test2.mapper")
    public class UserController { 
    
        @Autowired
        private UserService userService;
        @GetMapping("/getUser")
        public List<User> getUser(){
            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}]

## [demo下载][demo] ##

[http_localhost_8080_getUser]: http://localhost:8080/getUser
[demo]: https://download.csdn.net/download/qq_34158598/10286754