SpringBoot多数据源配置并通过注解实现动态切换数据源

2022-11-13 13:53

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1. 环境准备

1.1 数据库准备

一个本地环境的MySQL数据库，数据库mydb，创建表t_user

CREATE TABLE `t_user` (
  `c_id` varchar(20) NOT NULL,
  `c_username` varchar(20) DEFAULT NULL,
  `c_password` varchar(20) DEFAULT NULL,
  `c_gender` tinyint(2) DEFAULT NULL,
  PRIMARY KEY (`c_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;


INSERT INTO `mydb`.`t_user`(`c_id`, `c_username`, `c_password`, `c_gender`) VALUES ('1', '思思', '123', 1);

一个云服务器的MySQL数据库，创建数据库book_db，创建表t_userinfo。

CREATE TABLE `t_user_info` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户id',
  `user_name` varchar(50) DEFAULT NULL COMMENT '用户名',
  `password` varchar(255) DEFAULT NULL COMMENT '登录密码',
  `areaObj` varchar(255) DEFAULT NULL COMMENT '所在学院',
  `name` varchar(20) DEFAULT NULL COMMENT '姓名',
  `sex` tinyint(255) DEFAULT NULL COMMENT '性别',
  `user_photo` varchar(255) DEFAULT NULL COMMENT '学生照片',
  `birthday` varchar(20) DEFAULT NULL COMMENT '出生日期',
  `telephone` varchar(20) DEFAULT NULL COMMENT '联系电话',
  `address` varchar(255) DEFAULT NULL COMMENT '家庭地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

INSERT INTO `book_db`.`t_user_info`(`id`, `user_name`, `password`, `areaObj`, `name`, `sex`, `user_photo`, `birthday`, `telephone`, `address`) VALUES (1, '张三', '123', '哈尔滨', '张三散', 1, '123', '02-16', '15756892458', '黑龙江省哈尔滨市');

创建数据库chatroom，创建表admin。

CREATE TABLE `admin` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(20) NOT NULL COMMENT '登录账号',
  `nickname` varchar(20) NOT NULL COMMENT '昵称',
  `password` varchar(255) NOT NULL COMMENT '密码',
  `user_profile` varchar(255) DEFAULT NULL COMMENT '管理员头像',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;

INSERT INTO `chatroom`.`admin`(`id`, `username`, `nickname`, `password`, `user_profile`) VALUES (1, 'admin', '系统管理员', '$2a$10$PyloUEVGuO0fUZdfeIaROOTluRmccl.Scifa8S7Os0Wt.s4bDkb', 'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=1784117537,3335593911&fm=26&gp=0.jpg');

1.2 项目创建

创建SpringBoot项目，整合MyBatis-Plus。pom.xml引入的依赖：

<dependencies>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
		</dependency>

		<!--mybatis plus-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.0.1</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>
		<!--druid-->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>druid-spring-boot-starter</artifactId>
			<version>1.1.10</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-lang3</artifactId>
			<version>3.9</version>
		</dependency>

	</dependencies>

配置读取resource文件夹下的mapper文件

	<build>
		<resources>
			<resource>
				<directory>class="lazy" data-src/main/java</directory>
				<includes>
					<include>**
    CHATROOM("chatroom"),
    
    BOOK_DB("book_db"),
    
    MY_DB("mydb");

    private final String name;

    DataSourceTypeEnum(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

}

4.2 创建动态多数据源类

定义一个动态多数据源类DynamicDataSource用于管理不同线程间多个数据源的选择和切换，扩展 Spring 提供的 AbstractRoutingDataSource 抽象类，重写 determineCurrentLookupKey 方法,其中的determineCurrentLookupKey() 方法用于决定使用哪个数据源。

public class DynamicDataSource extends AbstractRoutingDataSource {

    
    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    
    public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
        super.setDefaultTargetDataSource(defaultTargetDataSource);
        super.setTargetDataSources(targetDataSources);
        super.afterPropertiesSet();
    }

    
    @Override
    protected Object determineCurrentLookupKey() {
        return getDataSource();
    }

    public static void setDataSource(String dataSource) {
        CONTEXT_HOLDER.set(dataSource);
    }

    public static String getDataSource() {
        return CONTEXT_HOLDER.get();
    }
    
    public static void clearDataSource() {
        CONTEXT_HOLDER.remove();
    }
}

4.3 创建动态多数据源配置类

DynamicDataSourceConfig类作为配置类，读取配置文件的三个数据源的配置，创建对应DataSource类型的Bean。

@Configuration
public class DynamicDataSourceConfig {

    @Bean(name="chatroom")
    @ConfigurationProperties("spring.datasource.druid.first")
    public DataSource dataSource1(){
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name ="book_db")
    @ConfigurationProperties("spring.datasource.druid.second")
    public DataSource dataSource2(){
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name="mydb")
    @ConfigurationProperties("spring.datasource.druid.third")
    public DataSource dataSource3(){
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name="dynamicDataSource")
    @Primary
    public DynamicDataSource dataSource() {
        Map<Object, Object> targetDataSources = new HashMap<>(5);
        targetDataSources.put(DataSourceTypeEnum.CHATROOM.getName(), dataSource1());
        targetDataSources.put(DataSourceTypeEnum.BOOK_DB.getName(), dataSource2());
        targetDataSources.put(DataSourceTypeEnum.MY_DB.getName(), dataSource3());
        return new DynamicDataSource(dataSource1(), targetDataSources);
    }
}

4.4 自定义注解用于指定数据源

自定义注解@SpecifyDataSource用于在Service层方法上标记要使用哪个数据源。这里定义默认使用数据源 DataSourceType.CHATROOM。

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SpecifyDataSource {

    
    DataSourceTypeEnum value() default DataSourceTypeEnum.CHATROOM;
}

4.5 AOP实现动态切换数据源

定义数据源界面类DataSourceAspect，用于实现有SpecifyDataSource注解标注的方法前切换注解指定的数据源。

@Aspect
@Component
@Order(value = 1)
public class DataSourceAspect {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Pointcut("@annotation(top.javahai.datasource.annotation.SpecifyDataSource)")
    public void dataSourcePointCut() {

    }

    @Around("dataSourcePointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();

        SpecifyDataSource ds = method.getAnnotation(SpecifyDataSource.class);
        if (ds == null) {
            DynamicDataSource.setDataSource(DataSourceType.CHATROOM.getName());
            logger.info("set datasource is " + DataSourceType.CHATROOM);
        } else {
            DynamicDataSource.setDataSource(ds.value().getName());
            logger.info("set datasource is " + ds.value().getName());
        }

        try {
            return point.proceed();
        } finally {
            DynamicDataSource.clearDataSource();
            logger.info("clean datasource");
        }
    }
}

5. 测试使用

5.1 配置数据源

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
# 数据源1
spring.datasource.druid.first.url=jdbc:mysql://158.156.444.68:3306/chatroom?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
spring.datasource.druid.first.username=root
spring.datasource.druid.first.password=123456
# 数据源2
spring.datasource.druid.second.url=jdbc:mysql://158.156.444.68:3306/book_db?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
spring.datasource.druid.second.username=root
spring.datasource.druid.second.password=123456

#数据源3
spring.datasource.druid.third.url=jdbc:mysql:///mydb?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
spring.datasource.druid.third.username=root
spring.datasource.druid.third.password=123456

mybatis-plus.mapper-locations=classpath:mapper
    private String username;

    
    private String nickname;

    
    private String password;

    
    private String userProfile;

//省略getter/setter方法

创建实体类TUser

public class TUser implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "c_id", type = IdType.AUTO)
    private Integer cId;

    private String cUsername;

    private String cPassword;

    private Integer cGender;
}

创建实体类TUserinfo

@TableName(value = "t_user_info")
public class TUserinfo implements Serializable {

    private static final long serialVersionUID = 1L;

    
    private String userName;

    
    private String password;

    
    @TableField("areaObj")
    private String areaObj;

    
    private String name;

    
    private Integer sex;

    
    private String userPhoto;

    
    private String birthday;

    
    private String telephone;

    
    private String address;
}

创建UserVO用于测试

public class UserVO {

    private List<Admin> adminList;
    private List<TUserinfo> tUserinfos;
    private List<TUser> tUsers;
}

5.3 服务层代码

@Service
public class AdminServiceImpl extends ServiceImpl<AdminMapper, Admin> implements IAdminService {

    public List<Admin> getAll(){
        return this.list(null);
    }
}

@Service
public class TUserinfoServiceImpl extends ServiceImpl<TUserinfoMapper, TUserinfo> implements ITUserinfoService {

    @SpecifyDataSource(value = DataSourceTypeEnum.BOOK_DB)
    public List<TUserinfo> selectAll(){
        return this.list(null);
    }

}

@Service
public class TUserServiceImpl extends ServiceImpl<TUserMapper, TUser> implements ITUserService {

    @SpecifyDataSource(value = DataSourceTypeEnum.MY_DB)
    public List<TUser> selectAll(){
        return this.list(null);
    }
}

public interface AdminMapper extends BaseMapper<Admin> {

}

public interface TUserinfoMapper extends BaseMapper<TUserinfo> {

}

public interface TUserMapper extends BaseMapper<TUser> {

}

5.4 控制层代码

创建接口/test/list用于测试

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    private AdminServiceImpl adminService;

    @Autowired
    private TUserinfoServiceImpl userinfoService;

    @Autowired
    private TUserServiceImpl userService;

    @GetMapping("/list")
    public UserVO list(){
        List<Admin> adminList= adminService.getAll();
        List<TUserinfo> tUserinfos = userinfoService.selectAll();
        List<TUser> tUsers = userService.selectAll();
        UserVO userVO = new UserVO();
        userVO.setAdminList(adminList);
        userVO.settUserinfos(tUserinfos);
        userVO.settUsers(tUsers);
        return userVO;
    }
}

浏览器请求/test/list

在这里插入图片描述