0001SpringBoot整合Mybatis

SpringBoot整合Mybatis主要分为以下几个步骤：

1、添加Mybatis的起步依赖(pom.xml)

2、添加数据库驱动坐标(pom.xml)

3.添加数据库连接信息（application.properties）

4、创建user表

5、创建实体Bean

6、编写Mapper接口，可理解为dao

7、配置Mapper接口对应的Mapper映射文件，可理解为dao的方法要执行的sql语句

8、在application.properties中添加Mybatis的相关信息

9、编写Controller

10、启动SpringBoot的引导类尽心测试

具体代码如下：

pom.xml中与整合Mybatis相关的配置如下：

<!--mybatis起步依赖-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.2.0</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <!--不需要填写版本号，因为在父依赖里已经给了判断-->
    <!--<version>5.1.39</version>-->
</dependency>

application.properties中的配置信息如下：

#数据库连接信息
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root@123
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#springboot集成mybatis
#pojo扫描
mybatis.type-aliases-package=come.itheima.domain
mybatis.mapper-locations=classpath:mapper/*Mapper.xml

建表语句以及插入两条测试数据，如下：

CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(50) DEFAULT NULL,
`password` varchar(50) DEFAULT NULL,
`name` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

insert into user values(1,'zhangsan','123','张三');
insert into user values(2,'lisi','123','李四');

user实体的内容如下：

package com.itheima.domain;

public class User {
    private int id;
    private String username;
    private String password;
    private String name;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", name='" + name + '\'' +
                '}';
    }
}

Mapper接口内容如下：

package com.itheima.mapper;

import com.itheima.domain.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserMapper {
    public List<User> queryUserList();
}

UserMapper.xml接口与执行sql的映射文件内容如下：

<?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.itheima.mapper.UserMapper">
    <select id="queryUserList" resultType="com.itheima.domain.User">
        select * from user
    </select>

</mapper>

controller代码内容如下：

package com.itheima.controller;

import com.itheima.domain.User;
import com.itheima.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
public class MybatisController {
    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/query")
    @ResponseBody
    public List<User> queryUserList(){
        List<User> users = userMapper.queryUserList();
        return users;

    }

}

默认生成的引导类内容如下：

package com.itheima;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootMybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootMybatisApplication.class, args);
    }

}

整体目录结构如下图：