Spring Boot 菜鸟教程 3 MyBatis

GitHub

MyBatis

MyBatis 本是apache的一个开源项目iBatis, 2010年这个项目由apache 迁移到了google code，并且改名为MyBatis 。2013年11月迁移到Github。

集成spring boot 的时候必须在mapper接口上面标注@Mapper注解

项目图片

pom.xml

-只需要在pom.xml引入需要的数据库配置，就会自动访问此数据库，如果需要配置其他数据库，可以在application.properties进行添加

-默认使用org.apache.tomcat.jdbc.pool.DataSource创建连接池

<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.jege.spring.boot</groupId>
<artifactId>spring-boot-mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>spring-boot-mybatis</name>
<url>http://maven.apache.org</url>

<!-- 公共spring-boot配置，下面依赖jar文件不用在写版本号 -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.1.RELEASE</version>
<relativePath />
</parent>

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

<dependencies>

<!-- 持久层 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>

<!-- h2内存数据库 -->
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>

</dependencies>

<build>
<finalName>spring-boot-mybatis</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

模型对象User

package com.jege.spring.boot.mybatis.entity;

/**
* @author JE哥
* @email 1272434821@qq.com
* @description:模型对象
*/
public class User {
private Long id;
private String name;
private Integer age;

public User() {
}

public User(String name, Integer age) {
this.name = name;
this.age = age;
}
}

持久层UserMapper

package com.jege.spring.boot.mybatis.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import com.jege.spring.boot.mybatis.entity.User;

/**
* @author JE哥
* @email 1272434821@qq.com
* @description:持久层接口，由spring自动生成其实现
*/
@Mapper
public interface UserMapper {
@Delete("drop table t_user if exists")
void dropTable();

@Insert("create table t_user (id bigint generated by default as identity, age integer, name varchar(255), primary key (id))")
void createTable();

@Insert("insert into t_user(name,age) values(#{name},#{age})")
void insert(User user);

@Select("select id,name,age from t_user")
List<User> findAll();

@Select("select id,name,age from t_user where name like #{name}")
List<User> findByNameLike(String name);

@Delete("delete from t_user")
void deleteAll();

}

不需要application.properties

测试类UserMapperTest

package com.jege.spring.boot.mybatis;

import static org.assertj.core.api.Assertions.assertThat;

import org.junit.After;
import org.junit.Before;
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.context.junit4.SpringJUnit4ClassRunner;

import com.jege.spring.boot.mybatis.entity.User;
import com.jege.spring.boot.mybatis.mapper.UserMapper;

/**
* @author JE哥
* @email 1272434821@qq.com
* @description:
*/
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest()
public class UserMapperTest {
@Autowired
UserMapper userMapper;

// 每次执行Test之前先删除表，创建表
@Before
public void before() throws Exception {
userMapper.dropTable();
userMapper.createTable();
}

// 打印出class com.sun.proxy.$Proxy66表示spring注入通过jdk动态代理获取接口的子类
@Test
public void proxy() throws Exception {
System.out.println(userMapper.getClass());
}

@Test
public void save() throws Exception {
for (int i = 0; i < 10; i++) {
User user = new User("jege" + i, 25 + i);
userMapper.insert(user);
}
}

@Test
public void all() throws Exception {
save();
assertThat(userMapper.findAll()).hasSize(10);
}

@Test
public void findByName() throws Exception {
save();
assertThat(userMapper.findByNameLike("jege%")).hasSize(10);
}

// 每次执行Test之后清空数据
@After
public void destroy() throws Exception {
userMapper.deleteAll();
}

}

源码地址

https://github.com/je-ge/spring-boot

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