Mybatis集成

Spring Boot中的JPA部分默认是使用的hibernate，而如果想使用Mybatis的话就需要自己做一些配置。使用方式有两种，第一种是Mybatis官方提供的 mybatis-spring-boot-starter ，第二种是类似 mybatis-spring的方式，需要自己写一些代码。但是可以更方便地控制Mybatis的各项配置。

mybatis-spring-boot-starter

这种方式只需要在application.properties中配置相关的Mybatis属性就可以了。数据源使用的是Spring Boot默认的数据源

mybatis.mapperLocations: mapper配置文件的路径，支持通配符方式
mybatis.typeAliasesPackage: 用来扫描Entity的包
mybatis.config：mybatis-config.xml配置文件的路径
mybatis.typeHandlersPackage：扫描typeHandlers的包
mybatis.checkConfigLocation：检查配置文件是否存在
mybatis.executorType：设置执行模式（SIMPLE, REUSE, BATCH），默认为SIMPLE

mybatis-spring方式

这种方式和平常的用法比较接近。需要添加mybatis依赖和mybatis-spring依赖。然后创建一个MyBatisConfig配置类：

package com.freud.test.springboot; import javax.sql.DataSource; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.SqlSessionTemplate; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import org.springframework.core.io.support.ResourcePatternResolver; import org.springframework.jdbc.datasource.DataSourceTransactionManager; import org.springframework.transaction.PlatformTransactionManager; import org.springframework.transaction.annotation.EnableTransactionManagement; import org.springframework.transaction.annotation.TransactionManagementConfigurer; /** * MyBatis基础配置 * * @author Freud */ @Configuration @EnableTransactionManagement public class MybatisConfig implements TransactionManagementConfigurer { @Autowired private DataSource dataSource; @Bean(name = "sqlSessionFactory") public SqlSessionFactory sqlSessionFactoryBean() { SqlSessionFactoryBean bean = new SqlSessionFactoryBean(); bean.setDataSource(dataSource); bean.setTypeAliasesPackage("com.freud.test.springboot"); // 添加XML目录 ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); try { bean.setMapperLocations(resolver.getResources("classpath:mapper/*.xml")); return bean.getObject(); } catch (Exception e) { e.printStackTrace(); throw new RuntimeException(e); } } @Bean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) { return new SqlSessionTemplate(sqlSessionFactory); } //

  * 因为添加了spring-boot-starter-
     * jdbc依赖，会触发DataSourceTransactionManagerAutoConfiguration这个自动化配置类
     * ，自动构造事务管理器，所以若只有一个数据源可以不必进行下面的配置

@Bean public PlatformTransactionManager annotationDrivenTransactionManager() { return new DataSourceTransactionManager(dataSource); } }

上面代码创建了一个SqlSessionFactory和一个SqlSessionTemplate，为了支持注解事务，增加了@EnableTransactionManagement注解，并且反回了一个PlatformTransactionManagerBean。

添加一个MyBatisMapperScannerConfig.java类，把mapper扫描单独放在这里配置（或者在Application 添加@MapperScan注解）

如果想要扫描MyBatis的Mapper接口, 就需要配置MapperScannerConfigurer。

package com.freud.test.springboot; import org.mybatis.spring.mapper.MapperScannerConfigurer; import org.springframework.boot.autoconfigure.AutoConfigureAfter; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * MyBatis扫描接口 * * @author Freud */ @Configuration // 注意，由于MapperScannerConfigurer执行的比较早，所以必须有下面的注解 @AutoConfigureAfter(MybatisConfig.class) public class MyBatisMapperScannerConfig { @Bean public MapperScannerConfigurer mapperScannerConfigurer() { MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer(); mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory"); mapperScannerConfigurer.setBasePackage("com.freud.test.springboot.mapper"); return mapperScannerConfigurer; } }

实验

本实验使用mybatis-spring-boot-starter方式。

创建一个Maven项目

/images/blog/spring-boot/22-integrate-with-mybatis/01-new-maven-project.png

pom.xml

<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.freud.test</groupId> <artifactId>spring-boot-22</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>spring-boot-22</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.0.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>1.5.4.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> </project>

application.yml

spring:
  application:
    name: test-22 jpa: generate-ddl: false show-sql: true hibernate: ddl-auto: none datasource: platform: MYSQL continue-on-error: false driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/test?useSSL=false username: root password: root schema: classpath:schema.sql data: classpath:data.sql server: port: 9090 mybatis: mapper-locations: classpath:mapper/*.xml type-aliases-package: com.freud.test.springboot

schema.sql

DROP TABLE IF EXISTS `user`; CREATE TABLE `user` ( `id` int(20) NOT NULL AUTO_INCREMENT, `name` varchar(50) NOT NULL, `age` int(10) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; DELETE FROM `user`;

data.sql

insert into user(id, name, age) values(1,'Freud1',29); insert into user(id, name, age) values(2,'Freud2',29); insert into user(id, name, age) values(3,'Freud3',29); insert into user(id, name, age) values(4,'Freud4',29); insert into user(id, name, age) values(5,'Freud5',29);

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN"
"http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">
<mapper namespace="com.freud.test.springboot.mapper.UserMapper"> <resultMap id="user" type="com.freud.test.springboot.bean.User"> <id property="id" jdbcType="INTEGER" column="ID"/> <result property="name" jdbcType="VARCHAR" column="NAME"/> <result property="age" jdbcType="INTEGER" column="AGE"/> </resultMap> <select id="getById" resultMap="user"> SELECT ID, NAME, AGE FROM USER WHERE ID = #{id} </select> <insert id="insert"> INSERT INTO USER ( NAME, AGE ) VALUES ( #{name}, #{age} ) </insert> <delete id="delete"> DELETE FROM USER WHERE ID = #{id} </delete> </mapper>

User.java

package com.freud.test.springboot.bean; /** * @author Freud */ public class User { private long id; private String name; private int 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 int getAge() { return age; } public void setAge(int age) { this.age = age; } }

UserController.java

package com.freud.test.springboot.controller; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import com.freud.test.springboot.bean.User; import com.freud.test.springboot.mapper.UserMapper; /** * @author Freud */ @RestController @RequestMapping("/user") public class UserController { public static final String RESULT_SUCCESS = "success"; public static final String RESULT_FAILED = "failed"; @Autowired private UserMapper userMapper; @GetMapping("/all") public List<User> all() { return userMapper.getAll(); } @GetMapping("/find") public User find(@RequestParam("id") long id) { return userMapper.getById(id); } @GetMapping("/save") public String save(User user) { try { userMapper.insert(user); return RESULT_SUCCESS; } catch (Exception e) { return RESULT_FAILED; } } @GetMapping("/delete") public String delete(@RequestParam("id") long id) { try { userMapper.delete(id); return RESULT_SUCCESS; } catch (Exception e) { return RESULT_FAILED; } } }

UserMapper.java

package com.freud.test.springboot.mapper; import java.util.List; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.Select; import com.freud.test.springboot.bean.User; /** * @author Freud */ public interface UserMapper { @Select("SELECT * FROM USER") public List<User> getAll(); public User getById(@Param("id") long id); public void insert(User user); public void delete(@Param("id") long id); }

App.java

package com.freud.test.springboot; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; /** * @author Freud */ @SpringBootApplication public class App { public static void main(String[] args) { SpringApplication.run(App.class, args); } }