Spring Boot学习(九)之Spring Boot整合MyBatis

前言

现在业界比较流行的数据操作层框架 MyBatis，下面就讲解下 Springboot 如何整合 MyBatis，这里使用的是注解配置SQL.

Spring中整合MyBatis就不多说了，最近大量使用Spring Boot，因此整理一下Spring Boot中整合MyBatis的步骤。搜了一下Spring Boot整合MyBatis的文章，方法都比较老，比较繁琐。查了一下文档，实际已经支持较为简单的整合与使用。下面就来详细介绍如何在Spring Boot中整合MyBatis，并通过注解方式实现映射。

整合MyBatis

新建Spring Boot项目

pom.xml中引入依赖
这里用到spring-boot-starter基础和spring-boot-starter-test用来做单元测试验证数据访问
引入连接mysql的必要依赖mysql-connector-java
引入整合MyBatis的核心依赖mybatis-spring-boot-starter
这里不引入spring-boot-starter-jdbc依赖，是由于mybatis-spring-boot-starter中已经包含了此依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>

<groupId>com.xiaojingg</groupId>
<artifactId>springbootstudy-demo9-mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>springbootstudy-demo9-mybatis</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>

<dependencies>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</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>1.1.1</version>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.21</version>
</dependency>

</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

同之前介绍的使用jdbc和spring-data连接数据库一样，在application.properties中配置mysql的连接配置

spring.datasource.url=jdbc:mysql://localhost:3306/test

spring.datasource.username=root

spring.datasource.password=root

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

同其他Spring Boot工程一样，简单且简洁的的完成了基本配置，下面看看如何在这个基础下轻松方便的使用MyBatis访问数据库。

使用MyBatis
在Mysql中创建User表，包含id(BIGINT)、name(INT)、age(VARCHAR)字段。同时，创建映射对象User

package com.xiaojingg.domain;

public class User {

private Long id;
private String name;
private Integer age;

public Long getId() {
return id;
}

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

public String getName() {
return name;
}

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

public Integer getAge() {
return age;
}

public void setAge(Integer age) {
this.age = age;
}

}

创建User映射的操作UserMapper，为了后续单元测试验证，实现插入和查询操作

package com.xiaojingg.domain;

import org.apache.ibatis.annotations.*;

@Mapper
public interface UserMapper {

@Select("SELECT * FROM USER WHERE NAME = #{name}")
User findByName(@Param("name") String name);

@Insert("INSERT INTO USER(NAME, AGE) VALUES(#{name}, #{age})")
int insert(@Param("name") String name, @Param("age") Integer age);

}
主类如下:
package com.xiaojingg;

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

@SpringBootApplication
public class SpringbootstudyDemo9MybatisApplication {

public static void main(String[] args) {
SpringApplication.run(SpringbootstudyDemo9MybatisApplication.class, args);
}
}
创建单元测试
测试逻辑：插入一条name=AAA，age=20的记录，然后根据name=AAA查询，打印数据
测试结束回滚数据，保证测试单元每次运行的数据环境独立,这里可以屏蔽这里注解!
package com.xiaojingg;

import com.xiaojingg.domain.User;
import com.xiaojingg.domain.UserMapper;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringRunner.class)
@SpringBootTest
//@Transactional
public class SpringbootstudyDemo9MybatisApplicationTests {
@Autowired
private UserMapper userMapper;
@Test
@Rollback
public void findByName() throws Exception {
userMapper.insert("AAA", 20);
User u = userMapper.findByName("AAA");
System.out.print("========================="+u.getAge().intValue());
}
}

运行截图如下: