6、Spring Boot 與MyBatis整合

摘要： 1.6 Spring Boot 與MyBatis整合 簡介 詳細介紹如何在Spring Boot中整合MyBatis，並通過註解方式實現對映。 完整原始碼： 1.6.1 建立 spring-boot-mybatis 專案 pom檔案如下 ...

1.6 Spring Boot 與MyBatis整合

簡介

• 詳細介紹如何在Spring Boot中整合MyBatis，並通過註解方式實現對映。
• 完整原始碼：

1.6.1 建立 spring-boot-mybatis 專案

• pom檔案如下

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

<name>spring-boot-mybatis</name>
<description>Demo project for Spring Boot MyBatis</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.0.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.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

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


</project>

這裡不引入spring-boot-starter-jdbc依賴，是由於mybatis-spring-boot-starter中已經包含了此依賴

• application.yml 配置資料庫連線

spring:
datasource:
username: root
url: jdbc:mysql://localhost:3306/test
password: root
driver-class-name: com.mysql.cj.jdbc.Driver

• 建立user表

CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

1.6.2 使用MyBatis註解方式

因為最初設計時，MyBatis 是一個 XML 驅動的框架。配置資訊是基於 XML 的，而且對映語句也是定義在 XML 中的。而到了 MyBatis 3，就有新選擇了。MyBatis 3 構建在全面且強大的基於 Java 語言的配置 API 之上。這個配置 API 是基於 XML 的 MyBatis 配置的基礎，也是新的基於註解配置的基礎。註解提供了一種簡單的方式來實現簡單對映語句，而不會引入大量的開銷。

1.6.2.1 User實體類

package com.hw.springbootmybatis.entity;

/**
 * @Description TODO
 * @Author hw
 * @Date 2018/11/19 1:10
 * @Version 1.0
 */
public class User {

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

// get set 方法
}

1.6.2.2 建立User對映的操作UserMapper

package com.hw.springbootmybatis.mapper;

import com.hw.springbootmybatis.entity.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

/**
 * @Description TODO
 * @Author hw
 * @Date 2018/11/19 1:14
 * @Version 1.0
 */
@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);

}

1.6.2.3 建立單元測試

package com.hw.springbootmybatis;

import com.hw.springbootmybatis.entity.User;
import com.hw.springbootmybatis.mapper.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;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootMybatisApplicationTests {

@Autowired
private UserMapper userMapper;

@Test
public void contextLoads() {
}


@Test
@Rollback
public void findByName() throws Exception {
userMapper.insert("AAA", 20);
User u = userMapper.findByName("AAA");
Assert.assertEquals(20, u.getAge().intValue());
}

}

1.6.2.4 原始碼地址

ofollow,noindex" target="_blank">註解方式原始碼

不幸的是，Java 註解的的表達力和靈活性十分有限。儘管很多時間都花在調查、設計和試驗上，最強大的 MyBatis 對映並不能用註解來構建——並不是在開玩笑，的確是這樣。比方說，C#屬性就沒有這些限制，因此 MyBatis.NET 將會比 XML 有更豐富的選擇。也就是說，基於 Java 註解的配置離不開它的特性。

1.6.3 使用MyBatis XML方式

1.6.3.1 yml檔案：

spring:
datasource:
username: root
url: jdbc:mysql://localhost:3306/test?characterEncoding=utf-8&serverTimezone=GMT%2B8
password: root
driver-class-name: com.mysql.cj.jdbc.Driver


mybatis:
config-location: classpath:mybatis-config.xml
mapper-locations: classpath:mapper/*.xml
type-aliases-package: com.hw.springbootmybatisxml.entity

1.6.3.2 建立配置檔案mybatis-config.xml

在resource目錄下建立config目錄並建立mybatis-config.xml檔案

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<setting name="callSettersOnNulls" value="true"/>
<setting name="cacheEnabled" value="true"/>
<setting name="lazyLoadingEnabled" value="true"/>
<setting name="aggressiveLazyLoading" value="true"/>
<setting name="multipleResultSetsEnabled" value="true"/>
<setting name="useColumnLabel" value="true"/>
<setting name="useGeneratedKeys" value="false"/>
<setting name="autoMappingBehavior" value="PARTIAL"/>
<setting name="defaultExecutorType" value="SIMPLE"/>
<setting name="mapUnderscoreToCamelCase" value="true"/>
<setting name="localCacheScope" value="SESSION"/>
<setting name="jdbcTypeForNull" value="NULL"/>
</settings>

<typeAliases>
<typeAlias alias="Integer" type="java.lang.Integer" />
<typeAlias alias="Long" type="java.lang.Long" />
<typeAlias alias="HashMap" type="java.util.HashMap" />
<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
<typeAlias alias="ArrayList" type="java.util.ArrayList" />
<typeAlias alias="LinkedList" type="java.util.LinkedList" />
</typeAliases>
</configuration>

1.6.3.3 在resource建立 mapper/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.hw.springbootmybatisxml.mapper.UserMapper">
<resultMap id="BaseResultMap" type="com.hw.springbootmybatisxml.entity.User">
<id column="id" property="id" jdbcType="NUMERIC"/>
<result column="name" property="name" jdbcType="VARCHAR"/>
<result column="age" property="age" jdbcType="NUMERIC"/>
</resultMap>

<sql id="Base_Column_List">
id, name, age
</sql>

<select id="findByName" parameterType="java.lang.String" resultMap="BaseResultMap">
SELECT
<include refid="Base_Column_List"/>
FROM user
WHERE name = #{name}
</select>

<!--如果涉及多個型別那就必須去掉parameterType；
第二個是#{id}...及後面的引數寫法也是錯誤的，
因為在MyBatis3中不會識別這樣的引數，所以應該改成#{arg0}，{arg1}這樣的形式。-->
<insert id="insert">
INSERT INTO
user
(name,age)
VALUES
(#{arg0}, #{arg1})
</insert>


</mapper>

1.6.3.4 User實體類

package com.hw.springbootmybatisxml.entity;

/**
 * @Description TODO
 * @Author hw
 * @Date 2018/11/19 1:10
 * @Version 1.0
 */
public class User {

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

// get set 方法
}

1.6.3.5 建立User對映的操作UserMapper

package com.hw.springbootmybatisxml.mapper;

import com.hw.springbootmybatisxml.entity.User;
import org.apache.ibatis.annotations.Mapper;

/**
 * @Description TODO
 * @Author hw
 * @Date 2018/11/19 1:36
 * @Version 1.0
 */
@Mapper
public interface UserMapper {

User findByName(String name);

void insert(String name,int age);

}

1.6.3.6 建立測試類

package com.hw.springbootmybatisxml;

import com.hw.springbootmybatisxml.entity.User;
import com.hw.springbootmybatisxml.mapper.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;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootMybatisXmlApplicationTests {

@Autowired
private UserMapper userMapper;

@Test
public void contextLoads() {
}


@Test
@Rollback
public void findByName() throws Exception {
userMapper.insert("ccc", 20);
User u = userMapper.findByName("ccc");
Assert.assertEquals(20, u.getAge().intValue());
}

}

1.6.3.7 原始碼

xml方式原始碼