SpringBoot - MyBatis 连接数据库

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>
<!-- MyBatis -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
<!-- MySql -->
<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

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