SpringBoot 自定义+动态切换数据源教程

1、添加maven依赖

<dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <scope>runtime</scope>
      </dependency>
      <dependency>
          <groupId>com.alibaba</groupId>
          <artifactId>druid</artifactId>
          <version>1.1.3</version>
      </dependency>
      <!--properties动态注入-->
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-configuration-processor</artifactId>
          <optional>true</optional>
      </dependency>
      <!--springBoot的aop-->
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-aop</artifactId>
      </dependency>

2、配置application.yml

# 数据库访问配置
# 主数据源，默认的
druid:
datasource:
  type: com.alibaba.druid.pool.DruidDataSource
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://192.168.1.113:3306/test?useUnicode=true&characterEncoding=utf-8
  username: root
  password: root
  # 下面为连接池的补充设置，应用到上面所有数据源中
  # 初始化大小，最小，最大
  initialSize: 5
  minIdle: 5
  maxActive: 20
  # 配置获取连接等待超时的时间
  maxWait: 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
  timeBetweenEvictionRunsMillis: 60000
  # 配置一个连接在池中最小生存的时间，单位是毫秒
  minEvictableIdleTimeMillis: 300000
  validationQuery: SELECT 1 FROM DUAL
  testWhileIdle: true
  testOnBorrow: false
  testOnReturn: false
  # 打开PSCache，并且指定每个连接上PSCache的大小
  poolPreparedStatements: true
  maxPoolPreparedStatementPerConnectionSize: 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
  filters: stat,wall,log4j
  # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
  connectionProperties:
    druid:
      stat:
        mergeSql: true
        slowSqlMillis: 5000
  # 合并多个DruidDataSource的监控数据
#多数据源
mysql-db:
datasource:
  names: logic,dao
  logic:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.113:3306/test1?useUnicode=true&characterEncoding=utf-8
    username: root
    password: root
  dao:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.113:3306/test2?useUnicode=true&characterEncoding=utf-8
    username: root
    password: root

3、配置动态数据源

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
* 动态数据源
* @author 陈梓平
* @date 2017/10/9.
*/
public class DynamicDataSource extends AbstractRoutingDataSource {
  @Override
  protected Object determineCurrentLookupKey() {
      return DataSourceHolder.getDataSource();
  }
}

4、配置数据源操作Holder

import java.util.ArrayList;
import java.util.List;
/**
* 数据源操作
* @author 陈梓平
* @date 2017/10/9.
*/
public class DataSourceHolder {
  //线程本地环境
  private static final ThreadLocal<String> contextHolders = new ThreadLocal<String>();
  //数据源列表
  public static List<String> dataSourceIds = new ArrayList<>();
  //设置数据源
  public static void setDataSource(String customerType) {
      contextHolders.set(customerType);
  }
  //获取数据源
  public static String getDataSource() {
      return (String) contextHolders.get();
  }
  //清除数据源
  public static void clearDataSource() {
      contextHolders.remove();
  }
  /**
   * 判断指定DataSrouce当前是否存在
   * @param dataSourceId
   * @return
   * @author SHANHY
   * @create  2016年1月24日
   */
  public static boolean containsDataSource(String dataSourceId){
      return dataSourceIds.contains(dataSourceId);
  }
}

5、读取自定义数据源. 并配置

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.bind.RelaxedDataBinder;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
* 数据源配置
* @author 陈梓平
* @date 2017/10/9.
*/
@Component
@Configuration
public class DynamicDataSourceConfig implements EnvironmentAware {
  private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceConfig.class);
  // 默认数据源
  private DataSource defaultDataSource;
  // 属性值
  private PropertyValues dataSourcePropertyValues;
  // 如配置文件中未指定数据源类型，使用该默认值
  private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource";
  private ConversionService conversionService = new DefaultConversionService();
  private Map<String, DataSource> customDataSources = new HashMap<>();
  @Override
  public void setEnvironment(Environment environment) {
      initDefaultDatasource(environment);
      initOtherDatasource(environment);
  }
  private void initOtherDatasource(Environment environment) {
      RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(environment, "mysql-db.datasource.");
      String dsPrefixs = propertyResolver.getProperty("names");
      for (String dsPrefix : dsPrefixs.split(",")) {// 多个数据源
          Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix+".");
          DataSource ds = buildDataSource(dsMap);
          customDataSources.put(dsPrefix, ds);
          dataBinder(ds, environment);
      }
  }
  private void initDefaultDatasource(Environment environment) {
      // 读取主数据源
      RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(environment, "druid.datasource.");
      Map<String, Object> dsMap = new HashMap<>();
      dsMap.put("type", propertyResolver.getProperty("type"));
      dsMap.put("driver-class-name", propertyResolver.getProperty("driver-class-name"));
      dsMap.put("url", propertyResolver.getProperty("url"));
      dsMap.put("username", propertyResolver.getProperty("username"));
      dsMap.put("password", propertyResolver.getProperty("password"));
      defaultDataSource = buildDataSource(dsMap);
      DataSourceHolder.dataSourceIds.add("ds1");
      dataBinder(defaultDataSource, environment);
  }
  /**
   * 创建DataSource
   * @param dsMap
   * @return
   * @author SHANHY
   * @create 2016年1月24日
   */
  @SuppressWarnings("unchecked")
  public DataSource buildDataSource(Map<String, Object> dsMap) {
      try {
          Object type = dsMap.get("type");
          if (type == null)
              type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource
          Class<? extends DataSource> dataSourceType;
          dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
          String driverClassName = dsMap.get("driver-class-name").toString();
          String url = dsMap.get("url").toString();
          String username = dsMap.get("username").toString();
          String password = dsMap.get("password").toString();
          DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
                  .username(username).password(password).type(dataSourceType);
          return factory.build();
      } catch (ClassNotFoundException e) {
          e.printStackTrace();
      }
      return null;
  }
  /**
   * 为DataSource绑定更多数据
   * @param dataSource
   * @param env
   * @author SHANHY
   * @create  2016年1月25日
   */
  private void dataBinder(DataSource dataSource, Environment env){
      RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);
      //dataBinder.setValidator(new LocalValidatorFactory().run(this.applicationContext));
      dataBinder.setConversionService(conversionService);
      dataBinder.setIgnoreNestedProperties(false);//false
      dataBinder.setIgnoreInvalidFields(false);//false
      dataBinder.setIgnoreUnknownFields(true);//true
      if(dataSourcePropertyValues == null){
          Map<String, Object> rpr = new RelaxedPropertyResolver(env, "druid.datasource.").getSubProperties(".");
          Map<String, Object> values = new HashMap<>(rpr);
          // 排除已经设置的属性
          values.remove("type");
          values.remove("driver-class-name");
          values.remove("url");
          values.remove("username");
          values.remove("password");
          dataSourcePropertyValues = new MutablePropertyValues(values);
      }
      dataBinder.bind(dataSourcePropertyValues);
  }
  @Bean(name = "dataSource")
  public DynamicDataSource dataSource() {
      DynamicDataSource dynamicDataSource = new DynamicDataSource();
      // 默认数据源
      dynamicDataSource.setDefaultTargetDataSource(defaultDataSource);
      // 配置多数据源
      Map<Object, Object> dsMap = new HashMap(5);
      dsMap.put("ds1", defaultDataSource);
      dsMap.putAll(customDataSources);
      for (String key : customDataSources.keySet())
          DataSourceHolder.dataSourceIds.add(key);
      dynamicDataSource.setTargetDataSources(dsMap);
      return dynamicDataSource;
  }
}

6、动态切换关键——AOP进行切换

/**
* 动态数据源注解
* @author 陈梓平
* @date 2017/10/9.
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({
      ElementType.METHOD
})
public @interface DS {
  String name() default "ds1";
}

import com.chen.config.dynamicDS.DataSourceHolder;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
/**
* 设置数据源切面
* @author 陈梓平
* @date 2017/10/9.
*/
@Aspect
@Order(-1)// 保证该AOP在@Transactional之前执行
@Component
public class DynamicDataSourceAspect {
  private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class);
  @Before("@annotation(ds)")
  public void changeDataSource(JoinPoint point, DS ds) throws Throwable {
      String dsId = ds.name();
      if (!DataSourceHolder.containsDataSource(dsId)) {
          logger.error("数据源[{}]不存在，使用默认数据源 > {}", ds.name(), point.getSignature());
      } else {
          logger.debug("Use DataSource : {} > {}", ds.name(), point.getSignature());
          DataSourceHolder.setDataSource(ds.name());
      }
  }
  @After("@annotation(ds)")
  public void restoreDataSource(JoinPoint point, DS ds) {
      logger.debug("Revert DataSource : {} > {}", ds.name(), point.getSignature());
      DataSourceHolder.clearDataSource();
  }
}

7、使用

1）、配置mapper

/**
* @author 陈梓平
* @date 2017/10/9.
*/
public interface DynamicDSMapper {
  Integer queryJournal();
  String queryUser();
  String queryType();
}

<?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.chen.mapper.DynamicDSMapper">
  <select id="queryJournal" resultType="java.lang.Integer">
      SELECT uid FROM journal
  </select>
  <select id="queryUser" resultType="java.lang.String">
      SELECT name FROM user
  </select>
  <select id="queryType" resultType="java.lang.String">
      SELECT parent FROM p_type
  </select>
</mapper>

2）、配置service

/**
* @author 陈梓平
* @date 2017/10/9.
*/
@Service
public class DynamicServciceImpl implements DynamicServcice {
  @Autowired
  private DynamicDSMapper dynamicDSMapper;
  @DS()
  public Integer ds1() {
      return dynamicDSMapper.queryJournal();
  }
  @DS(name = "logic")
  public String ds2() {
      return dynamicDSMapper.queryUser();
  }
  @DS(name = "dao")
  public String ds3() {
      return dynamicDSMapper.queryType();
  }
}

3）、单元测试调用

/**
* 多数原测试
* @author 陈梓平
* @date 2017/10/9.
*/
@RunWith(SpringRunner.class)
@SpringBootTest
public class TestDynamicDS {
  private Logger logger = LoggerFactory.getLogger(TestDynamicDS.class);
//
  @Autowired
  private DynamicServcice dynamicServcice;
  @Test
  public void test() {
//        Integer integer = dynamicServcice.ds1();
//        logger.info("integer:"+integer);
//        String ds2 = dynamicServcice.ds2();
//        logger.info("ds2:"+ds2);
      String ds3 = dynamicServcice.ds3();
      logger.info("ds3:"+ds3);
  }
}

4）、测试结果

以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程宝库。

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