Spring Boot整合Mybatis

Xuxx 2020-05-12 in 笔记

1.基本使用

1.依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.20</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
    <version>5.1.27</version>
</dependency>

2.配置数据源

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url=jdbc:mysql:///test?useSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=root

3.写代码

User

@Data
public class User {
    private Integer id;
    private String username;
    private String address;
}

UserMapper

//单个Mapper可以直接加@Mapper，也可以在启动类上加//@MapperScan(basePackages = "com.xuxx.mybatis.mapper")
@Mapper
public interface UserMapper {
//    @Select("select * from user ")
    List<User> getAllUsers();
}

Mapper.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.xuxx.mybatis.mapper.UserMapper">
    <select id="getAllUsers" resultType="com.xuxx.mybatis.bean.User">
        select * from user
    </select>
</mapper>

补充：

此时Mapper.xml会被Maven忽略，运行会报错org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.xuxx.mybatis.mapper.UserMapper.getAllUsers

解决方法：（三种方式任选其一即可）

在resources目录下创建与Mapper位置对应的多级目录com/xuxx/mybatis/mapper,并将Mapper.xml放到创建的目录下

在pom.xml文件中配置不忽略需要的xml文件

<build>
    ....
<!--让maven不忽略Mapper.xml-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
        </resources>

在resources目录下创建自定义目录，并在application.properties中配置

#将Mapper.xml文件放在resources目录的mapper下，再指定mapper.xml位置
mybatis.mapper-locations=classpath:mapper/*.xml

测试

@SpringBootTest
class MybatisApplicationTests {

    @Autowired
    UserMapper userMapper;

    @Test
    void contextLoads() {
        List<User> users = userMapper.getAllUsers();
        System.out.println(users);
    }
}

结果

[User(id=1, username=xu, address=四川), User(id=6, username=xu2, address=四川)]

2.配置多数据源

1.依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.20</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
    <version>5.1.27</version>
</dependency>

2.配置多数据源

#配置多数据源
spring.datasource.one.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.one.url=jdbc:mysql:///test?useSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.one.username=root
spring.datasource.one.password=root

spring.datasource.two.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.two.url=jdbc:mysql:///test2?useSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.two.username=root
spring.datasource.two.password=root

3.写代码

DataSourceConfig

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.one")
    DataSource dsOne() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.two")
    DataSource dsTwo() {
        return DruidDataSourceBuilder.create().build();
    }
}

MybatisConfigOne

@Configuration
@MapperScan(basePackages = "com.xuxx.mybatis2.mapper1", sqlSessionFactoryRef = "sqlSessionFactoryOne"
        , sqlSessionTemplateRef = "sqlSessionTemplateOne")
public class MybatisConfigOne {
    @Resource(name = "dsOne")
    DataSource dsOne;

    @Bean
    SqlSessionFactory sqlSessionFactoryOne() {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        try {
            bean.setDataSource(dsOne);
            return bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplateOne() {
        return new SqlSessionTemplate(sqlSessionFactoryOne());
    }
}

MybatisConfigTwo

@Configuration
@MapperScan(basePackages = "com.xuxx.mybatis2.mapper2", sqlSessionFactoryRef = "sqlSessionFactoryTwo"
        , sqlSessionTemplateRef = "sqlSessionTemplateTwo")
public class MybatisConfigTwo {
    @Resource(name = "dsTwo")
    DataSource dsTwo;

    @Bean
    SqlSessionFactory sqlSessionFactoryTwo() {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        try {
            bean.setDataSource(dsTwo);
            return bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplateTwo() {
        return new SqlSessionTemplate(sqlSessionFactoryTwo());
    }
}

到此，多数据源就配置好了，使用数据源1就在包mapper1下，使用数据源2就在包mapper2下。

测试一下

User

@Data
public class User {
    private Integer id;
    private String username;
    private String address;
}

com\xuxx\mybatis2\mapper1\UserMapper1.java

public interface UserMapper1 {
    @Select("select * from user ")
    List<User> getAllUsers();
}

com\xuxx\mybatis2\mapper2\UserMapper2.java

public interface UserMapper2 {
    @Select("select * from user ")
    List<User> getAllUsers();
}

测试类

@SpringBootTest
class Mybatis2ApplicationTests {
    @Autowired
    UserMapper1 userMapper1;
    @Autowired
    UserMapper2 userMapper2;

    @Test
    void contextLoads() {
        List<User> users1 = userMapper1.getAllUsers();
        System.out.println("user1："+users1);
        List<User> users2 = userMapper2.getAllUsers();
        System.out.println("user2："+users2);
    }

}

控制台

user1：[User(id=1, username=xu, address=四川), User(id=6, username=xu2, address=四川)]
user2：[User(id=1, username=zhangsan, address=四川2), User(id=2, username=lisi, address=北京2), User(id=3, username=xuxx, address=四川2)]