SpringBoot整合Mybatis多数据源 (AOP+注解)

Posted 2020-11-21 Architect剑

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了SpringBoot整合Mybatis多数据源 (AOP+注解)相关的知识，希望对你有一定的参考价值。

SpringBoot整合Mybatis多数据源 (AOP+注解)

1、pom.xml文件(开发用的JDK 10)

<?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.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.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>10</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.2.3</version>
        </dependency>
        
        <!-- 热部署 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

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


</project>

2、多数据源配置类

@Configuration
public class DataSourceConfig {
    
    @Bean(name = "readTestDb")
    @ConfigurationProperties(prefix = "spring.datasource.read-test-db") 
    public DataSource readTestDb() {
        return DataSourceBuilder.create().build();
    }


    @Bean(name = "writeTestDb")
    @ConfigurationProperties(prefix = "spring.datasource.write-test-db")
    public DataSource writeTestDb() {
        return DataSourceBuilder.create().build();
    }
    

    /**
     * 动态数据源: 通过AOP在不同数据源之间动态切换
     * @return
     */
    @Primary
    @Bean(name = "dynamicDataSource")
    public DataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        // 默认数据源
        dynamicDataSource.setDefaultTargetDataSource(readTestDb());
        // 配置多数据源
        Map<Object, Object> dsMap = new HashMap<Object, Object>();
        dsMap.put("readTestDb", readTestDb());
        dsMap.put("writeTestDb", writeTestDb());
 
        dynamicDataSource.setTargetDataSources(dsMap);
        return dynamicDataSource;
    }
 
    /**
     * 配置@Transactional注解事物
     * @return
     */
    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(dynamicDataSource());
    }

3、数据源切换读取类

public class DataSourceContextHolder {

    /**
     * 默认数据源
     */
    public static final String DEFAULT_DS = "readTestDb";
 
    private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
 
    // 设置数据源名
    public static void setDB(String dbType) {
        System.out.println("切换到{"+dbType+"}数据源");
        contextHolder.set(dbType);
    }
 
    // 获取数据源名
    public static String getDB() {
        return (contextHolder.get());
    }
 
    // 清除数据源名
    public static void clearDB() {
        contextHolder.remove();
    }

}

4、注解类(注意：要和配置类放在同一个包下，否则会抛出找不到注解异常)

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@Documented
public @interface DS {
    String value() default "readTestDb";
}

5、动态数据源(设置数据源自动调用该类方法)

public class DynamicDataSource extends AbstractRoutingDataSource  {

    @Override
    protected Object determineCurrentLookupKey() {
        System.out.println("数据源为"+DataSourceContextHolder.getDB());
        return DataSourceContextHolder.getDB();
    }

}

6、AOP

@Aspect
@Component
public class DynamicDataSourceAspect {
    
    @Before("@annotation(DS)")
    @SuppressWarnings("rawtypes")
    public void beforeSwitchDS(JoinPoint point){
        //获得当前访问的class
        Class<?> className = point.getTarget().getClass();
        //获得访问的方法名
        String methodName = point.getSignature().getName();
        //得到方法的参数的类型
        Class[] argClass = ((MethodSignature)point.getSignature()).getParameterTypes();
        String dataSource = DataSourceContextHolder.DEFAULT_DS;
        try {
            // 得到访问的方法对象
            Method method = className.getMethod(methodName, argClass);
            // 判断是否存在@DS注解
            if (method.isAnnotationPresent(DS.class)) {
                DS annotation = method.getAnnotation(DS.class);
                // 取出注解中的数据源名
                dataSource = annotation.value();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        // 切换数据源
        DataSourceContextHolder.setDB(dataSource);
    }
    
    @After("@annotation(DS)")
    public void afterSwitchDS(JoinPoint point){
        DataSourceContextHolder.clearDB();
    }
}

7、application.yml 配置文件 (和application.properties区别可以百度一下很详细)

spring:
    datasource:
        read-test-db:
            jdbc-url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8
            username: root
            password: root
            # 使用druid数据源
            type: com.alibaba.druid.pool.DruidDataSource
            driver-class-name: com.mysql.jdbc.Driver
            
        write-test-db:
            jdbc-url: jdbc:mysql://127.0.0.1:3306/writetest?useUnicode=true&characterEncoding=utf-8
            username: root
            password: root
            # 使用druid数据源
            type: com.alibaba.druid.pool.DruidDataSource
            driver-class-name: com.mysql.jdbc.Driver  
    jpa:
      show-sql: true

mybatis:
  #mapper-locations: classpath:mapping/mapper/*.xml
  type-aliases-package: com.example.demo.model

8、启动类( 注解：@MapperScan 扫描mapper接口类路径、多数据源 @SpringBootApplication这个注解是必须写的 )

@MapperScan("com.example.demo.mapper")
@SpringBootApplication(exclude = {
        DataSourceAutoConfiguration.class
})
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

9、Controller( 注解：@RestController( 包含@controller、@responseBody等其他注解所以用该注解就不用每个方法上@responseBody ) )

@RestController
public class DemoController {
    
    @Autowired
    private UserService userService;

    @RequestMapping("/getRequestDBObj")
    public User getRequestDBObj(HttpServletRequest request,HttpServletResponse response) {
        return userService.selectByPrimaryKey(1);
    }
    
    @RequestMapping("/getRequestDbList")
    public User getRequestDbList(HttpServletRequest request,HttpServletResponse response) {
        return userService.selectAllUser(1);
    }
}

10、Service

public interface UserService {
    
    public User selectByPrimaryKey(Integer userId);
    
    public User selectAllUser(Integer userId);
}

11、ServiceImpl

@Service
public class UserServiceImpl implements UserService {
    
    @Autowired
    private UserMapper userMapper;

    @Override
    @DS("writeTestDb")
    public User selectByPrimaryKey(Integer userId) {
        return userMapper.selectByPrimaryKey(userId);
    }

    @Override
    @DS("readTestDb")
    public User selectAllUser(Integer userId) {
        return userMapper.selectByPrimaryKey(userId);
    }
    
}

12、Mapper

public interface UserMapper {
    
    @Select("SELECT user_id as userId, user_name as userName, password, phone FROM t_user WHERE user_id = #{userId}")
    User selectByPrimaryKey(Integer userId);
    
}

13、本人 QQ 1036943655 本人萌新有代码不对的地方大家指教一下也可以加好友大家一起互相学习、互相进步

以上是关于SpringBoot整合Mybatis多数据源 (AOP+注解)的主要内容，如果未能解决你的问题，请参考以下文章

springboot 整合 mybatis 多数据源配置

SpringBoot-技术专区-Mybatis plus 实现多数据源整合

springboot整合mybatis的多数据源解决办法

SpringBoot：4.SpringBoot整合Mybatis实现数据库访问

SpringBoot2 配置多数据源，整合MybatisPlus增强插件

SpringBoot+Mybatis+ Druid+PageHelper 实现多数据源并分页