springboot

springboot+mybatis+druid配置动态数据源

2019-06-23  本文已影响0人  夜月河色

一、建数据库和表

1.数据库demo1放一张user表
SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` int(11) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'aa');
INSERT INTO `user` VALUES ('2', 'bb');
2.数据库demo2放一张role表
SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for role
-- ----------------------------
DROP TABLE IF EXISTS `role`;
CREATE TABLE `role` (
  `id` int(11) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of role
-- ----------------------------
INSERT INTO `role` VALUES ('1', 'CC');
INSERT INTO `role` VALUES ('2', 'DD');

二、pom.xml引入包

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>

        <!-- aop -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
        </dependency>
        <!-- alibaba druid-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <!-- dynamic-->
        <dependency>
            <groupId>com.typesafe.dynamicdatasource</groupId>
            <artifactId>dynamic-data-source_2.11</artifactId>
        </dependency>

三、用generator插件生成user、role两张表的实体类、mapper.java、mapper.xml

User.java
Role.java
UserMapper.java
RoleMapper.java
UserMapper.xml
RoleMapper.xml

四、配置application.yml

server:
  port: 8088

mybatis:
  mapper-locations: classpath:mapper/*.xml

spring:
  datasource:
      db1:
        url: jdbc:mysql://localhost:3306/demo1?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT
        username: root
        password: root
        type: com.alibaba.druid.pool.DruidDataSource
        #驱动包
        driver-class-name: com.mysql.cj.jdbc.Driver
        #初始连接数
        initial-size: 5
        #最小空闲数
        min-idle: 5
        #最大活动数
        max-active: 20
        #等待超时时间
        max-wait: 60000
        #配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
        time-between-eviction-runs-millis: 60000
        # 配置一个连接在池中最小生存的时间，单位是毫秒
        min-evictable-idle-time-millis: 300000
        #验证数据库连接的查询语句,MYSQL是select 1
        validation-query: SELECT 1 FROM DUAL
        #空闲时测试，testOnBorrow和testOnReturn在生产环境一般是不开启的，主要是性能考虑。失效连接主要通过testWhileIdle保证
        test-while-idle: true
        test-on-borrow: false
        test-on-return: false
        #打开PSCache，并指定每个链接上的PSCache大小
        pool-prepared-statements: true
        max-pool-prepared-statement-per-connection-size: 20
        #配置监控统计拦截的filters,去掉后监控界面sql无法统计，‘wall’用于防火墙，此处是filter修改的地方
        filters: stat,wall
        #通过connectproperties属性来打开mergesql功能：慢sql记录
        connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
        #合并多个DruidDataSource
        useGlobalDataSourceStat: true
      db2:
        url: jdbc:mysql://localhost:3306/demo2?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT
        username: root
        password: root
        type: com.alibaba.druid.pool.DruidDataSource
        #驱动包
        driver-class-name: com.mysql.cj.jdbc.Driver
        #初始连接数
        initial-size: 5
        #最小空闲数
        min-idle: 5
        #最大活动数
        max-active: 20
        #等待超时时间
        max-wait: 60000
        #配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
        time-between-eviction-runs-millis: 60000
        # 配置一个连接在池中最小生存的时间，单位是毫秒
        min-evictable-idle-time-millis: 300000
        #验证数据库连接的查询语句,MYSQL是select 1
        validation-query: SELECT 1 FROM DUAL
        #空闲时测试，testOnBorrow和testOnReturn在生产环境一般是不开启的，主要是性能考虑。失效连接主要通过testWhileIdle保证
        test-while-idle: true
        test-on-borrow: false
        test-on-return: false
        #打开PSCache，并指定每个链接上的PSCache大小
        pool-prepared-statements: true
        max-pool-prepared-statement-per-connection-size: 20
        #配置监控统计拦截的filters,去掉后监控界面sql无法统计，‘wall’用于防火墙，此处是filter修改的地方
        filters: stat,wall
        #通过connectproperties属性来打开mergesql功能：慢sql记录
        connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
        #合并多个DruidDataSource
        useGlobalDataSourceStat: true

五、启动类扫描mapper.java文件

@SpringBootApplication
@MapperScan("com.example.demo.dao")
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

六、定义DataSourceConfig， 将application.yml中的配置导入DataSource中，并注入到bean

@Configuration
public class DataSourceConfig {
    //从配置文件配置数据源
    @Primary
    @Bean(name="datasource1")
    @ConfigurationProperties("spring.datasource.db1")
    public DataSource dataSource1(){
        return new DruidDataSource();
    }

    //从配置文件配置数据源
    @Bean(name="datasource2")
    @ConfigurationProperties("spring.datasource.db2")
    public DataSource dataSource2(){
        return new DruidDataSource();
    }

    //动态数据源 进行数据源切换
    @Bean(name="dynamicDataSource")
    public DataSource dynamicDataSource(){
        DynamicDataSource dynamicDatasource=new DynamicDataSource();
        //设置默认数据源
        dynamicDatasource.setDefaultTargetDataSource(dataSource1());
        //配置多数据源
        Map<Object,Object> dsMap=new HashMap<>();
        dsMap.put("datasource1",dataSource1());
        dsMap.put("datasource2",dataSource2());
        //将多数据源放到数据源池中
        dynamicDatasource.setTargetDataSources(dsMap);
        return dynamicDatasource;
    }
}

七、定义动态数据源切换类DynamicDataSourceContextHolder

public class DynamicDataSourceContextHolder {
    private static final ThreadLocal<String> contextHolder=new ThreadLocal<>();

    //设置数据源名称
    public static void setDB(String dbType){
        contextHolder.set(dbType);
    }

    //获取数据源名称
    public static String getDB(){
        return contextHolder.get();
    }

    //清除数据源名
    public static void clearDB(){
        contextHolder.remove();
    }
}

八、定义获取动态数据源类DynamicDataSource

public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDB();
    }
}

九、定义mybatis配置类，将DynamicDataSource放入SqlSessionFactoryBean中

@EnableTransactionManagement
@Configuration
public class MyBatisConfig {
    @Resource(name = "dynamicDataSource")
    private DataSource dynamicDataSource;

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dynamicDataSource);//将动态数据源bean配置到sqlsessionfactory
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*.xml"));
        return sqlSessionFactoryBean.getObject();
    }

    @Bean
    public PlatformTransactionManager platformTransactionManager() {
        return new DataSourceTransactionManager(dynamicDataSource);
    }
}

十、定义用于切换数据源的注解TargetDataSource

@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource {
    String value() default "datasource1";
}

十一、定义切面DynamicDataSourceAspect，用于拦截注解，并执行数据源切换功能

@Aspect
@Component
public class DynamicDataSourceAspect {
    @Before("@annotation(targetDataSource)")
    public void beforeSwitchDS(JoinPoint point,TargetDataSource targetDataSource){
        DynamicDataSourceContextHolder.setDB(targetDataSource.value());
    }

    @After("@annotation(targetDataSource)")
    public void afterSwitchDS(JoinPoint point,TargetDataSource targetDataSource){
        DynamicDataSourceContextHolder.clearDB();
    }
}

十二、测试类Test

@RestController
public class Test {
    @Autowired
    private RoleMapper roleMapper;
    @Autowired
    private UserMapper userMapper;

    //未使用TargetDataSource注解，则使用默认数据源，即datasource1
    @RequestMapping("/ds1")
    public String selectDataSource1(){
        return userMapper.selectByPrimaryKey(1).toString();
    }

    //使用了注解，则数据源为注解中指定的datasource2
    @RequestMapping("/ds2")
    @TargetDataSource("datasource2")
    public String selectDataSource2(){
        return roleMapper.selectByPrimaryKey(1).toString();
    }
}

测试

1.输入

http://localhost:8088/ds1

返回
↓


DynamicDataSourceRegister_百度搜索.png

2.输入

http://localhost:8088/ds2

返回
↓


123545646.png
结论：两次请求分别从不同的数据库获取到了数据，多数据源配置成功！
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