SpringBoot 集成 mybatis的四种方式

约定不等于承诺〃 2021-11-17 03:26 272阅读 0赞

关于springBoot集成mybatis的方式，其实有很多，网上也有很多的案例，经过一系列参考和实践，大致有以下几种方式。

## 方式一 ##

（使用注解形式，全程无MyBatis与Spring的配置文件）

**1、添加依赖**

<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>
    </dependency>

**2、配置文件 application.yml**

**3、Controller**

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    import com.chenqi.springboot.service.TestService;
    @RestController
    public class SpringBootController {
        
        @Autowired
        TestService testService;
        @GetMapping("/hello")
        public String hello(){
            return testService.test();
        }
    }

**4、service**

public interface TestService {
        
        public String test();
    }

**5、serviceImpl**

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import com.chenqi.springboot.dao.TestMapper;
    import com.chenqi.springboot.service.TestService;
    @Service
    public class TestServiceImpl implements TestService {
        
        @Autowired
        TestMapper testMapper;
        @Override
        public String test() {
            return testMapper.test();
        }
    }

**6、dao**

import org.apache.ibatis.annotations.Mapper;
    import org.apache.ibatis.annotations.Select;
    @Mapper
    public interface TestMapper {
        
        @Select("select * from test")
        String test();
    }

**7、数据库**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70]

这里就简单建一张表 一个字段

启动项目后，浏览器输入：  
[http://localhost:8080/hello][http_localhost_8080_hello]  
返回：  
![在这里插入图片描述][20190729202842406.]

**方式二（使用注解+xml）**  
在上面的基础上修改

**1、配置文件 application.yml**

#配置数据源
    spring:
      datasource:
         url: jdbc:mysql://127.0.0.1:3306/test1?useUnicode=true&characterEncoding=utf8&useSSL=false
         username: root
         password: 123456
         driver-class-name: com.mysql.jdbc.Driver
         
    #指定mybatis映射文件的地址
    mybatis:
      mapper-locations: classpath:mapper/*.xml

**2、dao**

import org.apache.ibatis.annotations.Mapper;
    
    @Mapper
    public interface TestMapper {
    String test();
    }

**3、mapper.xml (注意文件名需与dao中的mapper相同)**

<?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.chenqi.springboot.dao.TestMapper" >
          <select id="test" resultType="java.lang.String">
            select * from test
        </select>
    </mapper>

启动项目后，浏览器输入：  
[http://localhost:8080/hello][http_localhost_8080_hello]  
返回：  
![在这里插入图片描述][20190729202949409.]

## 方式三（自定义dataSource，适合集成springcloud-config） ##

**1、添加依赖**

<dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>

**2、配置文件application.properties**

#jdbc
    jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://127.0.0.1:3306/test1?useSSL=false&useUnicode=true&characterEncoding=utf8
    jdbc.username=root
    jdbc.password=123456
    jdbc.maxActive=50
    jdbc.maxWait=30000

**3、自定义配置类**

**DataSourceConfiguration.java**

import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.PropertySource;
    import com.alibaba.druid.pool.DruidDataSource;
    @Configuration
    @PropertySource("classpath:application.properties")
    public class DataSourceConfiguration {
      @Value("${jdbc.driver}")
      private String driver;
      @Value("${jdbc.url}")
      private String url;
      @Value("${jdbc.username}")
      private String username;
      @Value("${jdbc.password}")
      private String password;
      @Value("${jdbc.maxActive}")
      private int maxActive;
      @Value("${jdbc.maxWait}")
      private long maxWait;
      
      @Bean
      public DruidDataSource dataSource(){
          DruidDataSource dataSource = new DruidDataSource();
          dataSource.setDriverClassName(driver);
          dataSource.setUrl(url);
          dataSource.setUsername(username);
          dataSource.setPassword(password);
          dataSource.setMaxActive(maxActive);
          dataSource.setMaxWait(maxWait);
          return dataSource;
      }
    }

**MyBatisConfig.java**

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;
    @Configuration
    @EnableTransactionManagement
    public class MyBatisConfig implements TransactionManagementConfigurer {
        @Autowired
        private DataSource dataSource;
        @Override
        public PlatformTransactionManager annotationDrivenTransactionManager() {
             return new DataSourceTransactionManager(dataSource);
        }
        @Bean(name = "sqlSessionFactory")
        public SqlSessionFactory sqlSessionFactoryBean() {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dataSource);
            //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);
        }
    }

**MyBatisMapperScannerConfig.java**

import org.mybatis.spring.mapper.MapperScannerConfigurer;
    import org.springframework.boot.autoconfigure.AutoConfigureAfter;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    @Configuration
    //因为这个对象的扫描，需要在MyBatisConfig的后面注入，所以加上下面的注解
    @AutoConfigureAfter(MyBatisConfig.class)
    public class MyBatisMapperScannerConfig {
        
        
     @Bean
     public MapperScannerConfigurer mapperScannerConfigurer() {
         MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
         //获取之前注入的beanName为sqlSessionFactory的对象
         mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
         //指定dao的路径
         mapperScannerConfigurer.setBasePackage("com.chenqi.springboot.dao");
         return mapperScannerConfigurer;
     }
    }

启动项目后，浏览器输入：  
[http://localhost:8080/hello][http_localhost_8080_hello]  
返回：

![在这里插入图片描述][20190729203213134.]

## 方式四（多数据源的mybatis） ##

**1、配置文件 application.yml**

mysql:
      server:
        test1:
          url: jdbc:mysql://127.0.0.1:3306/test1?useSSL=false&useUnicode=true&characterEncoding=utf8
          username: root
          password: 123456
          driverClassName: com.mysql.jdbc.Driver
          initialSize: 1
          minIdle: 5
          maxActive: 50
        test2:
          url: jdbc:mysql://127.0.0.1:3306/test2?useSSL=false&useUnicode=true&characterEncoding=utf8
          username: root
          password: 123456
          driverClassName: com.mysql.jdbc.Driver
          initialSize: 1
          minIdle: 5
          maxActive: 50

**2、数据库创建**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 1]

**3、dao 和 xml**

**Test1Mapper.java**

package com.chenqi.springboot.dao.test1;
    public interface Test1Mapper {
        
        String test();
    }

**Test2Mapper.java**

package com.chenqi.springboot.dao.test2;
    public interface Test2Mapper {
        
        String test();
    }

**Test1Mapper.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.chenqi.springboot.dao.test1.Test1Mapper" >
          <select id="test" resultType="java.lang.String">
            select * from test
        </select>
    </mapper>

**Test2Mapper.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.chenqi.springboot.dao.test2.Test2Mapper" >
          <select id="test" resultType="java.lang.String">
            select * from test
        </select>
    </mapper>

**3、serviceImpl**

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import com.chenqi.springboot.dao.test1.Test1Mapper;
    import com.chenqi.springboot.dao.test2.Test2Mapper;
    import com.chenqi.springboot.service.TestService;
    @Service
    public class TestServiceImpl implements TestService {
        
        @Autowired
        Test1Mapper test1Mapper;
        @Autowired
        Test2Mapper test2Mapper;
        @Override
        public String test() {
            return test1Mapper.test() + "---" + test2Mapper.test();
        }
    }

**4、 启动类**

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
    import com.chenqi.springboot.config.MyBadisLoader;
    @MyBadisLoader({"test1 = com.chenqi.springboot.dao.test1 = classpath:mapper/test1/*xml" , 
    "test2 = com.chenqi.springboot.dao.test2 = classpath:mapper/test2/*.xml"})
    @SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
    public class SpringbootApplication {
        public static void main(String[] args) {
            SpringApplication.run(SpringbootApplication.class, args);
        }
    }

启动项目后，浏览器输入：  
[http://localhost:8080/hello][http_localhost_8080_hello]  
返回：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 2]

好了，暂时就写这么多了，这四种足够应付大部分使用场景了

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70]: /images/20211116/d9776a48ee704c14ae6825b5b10c77cb.png
[http_localhost_8080_hello]: http://localhost:8080/hello
[20190729202842406.]: /images/20211116/729b5bbc245a45f2b3cf226744760d64.png
[20190729202949409.]: /images/20211116/4e002361215043778f179c2dc455afca.png
[20190729203213134.]: /images/20211116/06e682d0d0694880a475844b1e3e67ce.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 1]: /images/20211116/61473995e93243c487112764e96aa1d3.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MDYyMzczNg_size_16_color_FFFFFF_t_70 2]: /images/20211116/58f0f06fe52e4abd8b50e86868e1f339.png