SpringBoot动态数据源

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1、原理图

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2、创建枚举类

package com.yeqm.demo.sys;/**
*@Description 存数据源key值
*@Param 
*@Return 
*@Author 骑牛小道士
*@Date 2019/5/30
*@Time 17:43
*/
public enum DataSourceKey {master,salve,migration
}

3、创建自定义注解类

package com.yeqm.demo.sys;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;/**
*@Description 自定义注解
*@Param
*@Return
*@Author 骑牛小道士
*@Date 2019/5/30
*@Time 17:45
*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface TargetDataSource {String value() default "master";
}

4、切换数据源类

package com.yeqm.demo.sys;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;/***@Description 根据线程动态切换数据源*@Param *@Return *@Author 骑牛小道士*@Date 2019/5/30*@Time 17:47*/
@Configuration
public class DynamicDataSourceContextHolder {private static final Logger log = LoggerFactory.getLogger(DynamicDataSourceContextHolder.class);/*** 设置默认数据源*/public static  String DEFAULT_DS = "master";/***用于轮训计数*/private static int counter = 0;/** 当使用ThreadLocal维护变量时，ThreadLocal为每个使用该变量的线程提供独立的变量副本，* 所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。*/private static final ThreadLocal<String> contextHolder = ThreadLocal.withInitial(() -> DataSourceKey.master.name());/***用于在切换数据源时保证不会被其他线程修改*/public static Lock lock = new ReentrantLock();/*** 设置数据源*/public static void setDB(String dbType){log.info("切换到{" + dbType + "}数据源");contextHolder.set(dbType);}/*** 得到数据源**/public static String getDB(){return contextHolder.get();}/*** 使用主数据源*/public static void useMasterDataSource() {contextHolder.set(DataSourceKey.master.name());}/*** 移除数据源*/public static void removeDB(){contextHolder.remove();}/*** The constant slaveDataSourceKeys.*/public static List<Object> slaveDataSourceKeys = new ArrayList<>();/*** 当使用只读数据源时通过轮循方式选择要使用的数据源*/public static String getSlaveDB(){lock.lock();try {int datasourceKeyIndex = counter % slaveDataSourceKeys.size();counter++;return String.valueOf(slaveDataSourceKeys.get(datasourceKeyIndex));} catch (Exception e) {log.error(e.getMessage(), e);e.printStackTrace();return "master";} finally {lock.unlock();}}
}

5、获取数据源类

package com.yeqm.demo.sys;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/**
*@Description 多数据源的选择
*@Param 
*@Return 
*@Author 骑牛小道士
*@Date 2019/5/30
*@Time 17:48
*/
public class DynamicDataSource extends AbstractRoutingDataSource {private static final Logger log = LoggerFactory.getLogger(DynamicDataSource.class);@Overrideprotected Object determineCurrentLookupKey() {log.info("Current DataSource is " + DynamicDataSourceContextHolder.getDB());return DynamicDataSourceContextHolder.getDB();}
}

6、Aop类

package com.yeqm.demo.sys;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.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.lang.reflect.Method;/***@Description 自定义注解 + AOP的方式实现数据源动态切换。*@Param*@Return*@Author 骑牛小道士*@Date 2019/5/30*@Time 17:50*/
@Aspect
@Component
public class DynamicDataSourceAspect {private static final Logger log = LoggerFactory.getLogger(DynamicDataSourceAspect.class);@Before("@annotation(TargetDataSource)")public void beforeSwitchDB(JoinPoint joinPoint, TargetDataSource TargetDataSource){//获取目标类的方法Class<?> aClass = joinPoint.getTarget().getClass();//获得访问的方法名String methodName = joinPoint.getSignature().getName();//得到方法的参数类型Class[] parameterTypes = ((MethodSignature) joinPoint.getSignature()).getParameterTypes();String dataSource = DynamicDataSourceContextHolder.DEFAULT_DS;try {Method method = aClass.getMethod(methodName, parameterTypes);if(method.isAnnotationPresent(TargetDataSource.class)){TargetDataSource db = method.getAnnotation(TargetDataSource.class);//指定数据源dataSource = db.value();}else{//轮训设置数据源dataSource = DynamicDataSourceContextHolder.getSlaveDB();}} catch (NoSuchMethodException e) {log.error(e.getMessage(), e);}//设置数据源DynamicDataSourceContextHolder.setDB(dataSource);}@After("@annotation(TargetDataSource)")public void afterSwitchDB(TargetDataSource TargetDataSource){DynamicDataSourceContextHolder.removeDB();}
}

7、application.yml文件

spring:datasource:druid:# 数据库访问配置, 使用druid数据源 1master:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://62.234.72.109:3306/test11username: rootpassword: ******initial-size: 1min-idle: 1max-active: 20test-on-borrow: true# MySQL 8.x: com.mysql.cj.jdbc.Driver# 数据库访问配置, 使用druid数据源 1salve:driver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://62.234.72.109:3306/test12username: rootpassword: ******initial-size: 1min-idle: 1max-active: 20test-on-borrow: true# MySQL 8.x: com.mysql.cj.jdbc.Driver# 数据库访问配置, 使用druid数据源 1migration:# MySQL 8.x: com.mysql.cj.jdbc.Driverdriver-class-name: com.mysql.cj.jdbc.Driverjdbc-url: jdbc:mysql://62.234.72.109:3306/test13username: rootpassword: ******initial-size: 1min-idle: 1max-active: 20test-on-borrow: true

9、数据源配置类

package com.yeqm.demo.config;import com.yeqm.demo.sys.DataSourceKey;
import com.yeqm.demo.sys.DynamicDataSource;
import com.yeqm.demo.sys.DynamicDataSourceContextHolder;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;import javax.sql.DataSource;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;/**
*@Description 数据源配置类
*@Param 
*@Return 
*@Author 骑牛小道士
*@Date 2019/5/30
*@Time 17:57
*/
@Configuration
public class DataSourceConfig {/*** 主数据** @return data source*/@Bean("master")@Primary@ConfigurationProperties(prefix = "spring.datasource.druid.master")public DataSource master() {return DataSourceBuilder.create().build();}/*** 从数据库** @return data source*/@Bean("salve")@ConfigurationProperties(prefix ="spring.datasource.druid.salve")public DataSource slave() {return DataSourceBuilder.create().build();}/*** 从数据库** @return data source*/@Bean("migration")@ConfigurationProperties(prefix ="spring.datasource.druid.migration")public DataSource migration() {return DataSourceBuilder.create().build();}/*** 配置动态数据源** @return*/@Bean("dynamicDataSource")public DataSource dynamicDataSource() {DynamicDataSource dynamicRoutingDataSource = new DynamicDataSource();Map<Object, Object> dataSourceMap = new HashMap<>(4);dataSourceMap.put(DataSourceKey.master.name(), master());dataSourceMap.put(DataSourceKey.salve.name(), slave());dataSourceMap.put(DataSourceKey.migration.name(), migration());//设置默认的数据源dynamicRoutingDataSource.setDefaultTargetDataSource(master());// 多个slave数据源在此添加，自定义key，用于轮询dataSourceMap.put(DataSourceKey.salve.name() + "1", slave());//设置目标数据源dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);//将数据源的key放在集合中判断是否正常DynamicDataSourceContextHolder.slaveDataSourceKeys.addAll(dataSourceMap.keySet());//实现负载均衡算法   将 Slave 数据源的 key 放在集合中，用于轮循DynamicDataSourceContextHolder.slaveDataSourceKeys.addAll(dataSourceMap.keySet());DynamicDataSourceContextHolder.slaveDataSourceKeys.remove(DataSourceKey.migration.name());return dynamicRoutingDataSource;}/*** 设置工厂类*/@Beanpublic SqlSessionFactoryBean sqlSessionFactoryBean() {SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();sqlSessionFactoryBean.setDataSource(dynamicDataSource());//此处设置为了解决找不到mapper文件的问题try {sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/*Mapper.xml"));} catch (IOException e) {e.printStackTrace();}return sqlSessionFactoryBean;}/*** 事物管理器*/@Bean("transactionManager")public DataSourceTransactionManager transactionManager() {return new DataSourceTransactionManager(dynamicDataSource());}
}

10、启动类

package com.yeqm.demo;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/***@Description springboot入口类,此类需要在所有用到的package上层 exclude ={DataSourceAutoConfiguration.class}*@Param  禁用springboot默认加载的application.properties单数据源配置*@Return *@Author 骑牛小道士*@Date 2019/5/30*@Time 17:57
*/
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}}

11、测试

controller类

package com.yeqm.demo.controller;import com.yeqm.demo.biz.TBdUserBiz;
import com.yeqm.demo.entity.TBdUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;/*** @description:* @author: 骑牛小道士* @date: 2019-05-30 11:48*/
@Controller
public class TBdUserController {@Autowiredprivate TBdUserBiz tBdUserBiz;@RequestMapping("/999")public List<TBdUser> selectList1 (TBdUser param){List<TBdUser> list1 =tBdUserBiz.selectList1(param);List<TBdUser> list2 =tBdUserBiz.selectList2(param);List<TBdUser> list3 =tBdUserBiz.selectList3(param);return list1;}
}

biz 类

package com.yeqm.demo.biz;import com.yeqm.demo.entity.TBdUser;
import com.yeqm.demo.mapper.TBdUserMapper;
import com.yeqm.demo.sys.TargetDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;/*** @description:* @author: 骑牛小道士* @date: 2019-05-30 11:49*/@Service
public class TBdUserBiz {@Autowiredprivate TBdUserMapper tBdUserMapper;@TargetDataSource("migration")public List<TBdUser> selectList3(TBdUser param) {List<TBdUser> list= tBdUserMapper.selectList(param);System.out.println("migration");System.out.println(list.get(0).getUserCode());return list;}@TargetDataSource("salve")public List<TBdUser> selectList2(TBdUser param) {List<TBdUser> list= tBdUserMapper.selectList(param);System.out.println("salve");System.out.println(list.get(0).getUserCode());return list;}@TargetDataSource("master")public List<TBdUser> selectList1(TBdUser param) {List<TBdUser> list= tBdUserMapper.selectList(param);System.out.println("master");System.out.println(list.get(0).getUserCode());return list;}
}

mapper 类

package com.yeqm.demo.mapper;import com.yeqm.demo.entity.TBdUser;
import com.yeqm.utils.MyMapper;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;/**
*@Description 
*@Param 
*@Return 
*@Author 骑牛小道士
*@Date 2019/5/30
*@Time 18:04
*/
@Mapper
public interface TBdUserMapper extends MyMapper<TBdUser> {List<TBdUser> selectList(TBdUser param);
}

xml 文件

<?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.yeqm.demo.mapper.TBdUserMapper"><resultMap id="BaseResultMap" type="com.yeqm.demo.entity.TBdUser"><!--WARNING - @mbg.generated--><id column="row_id" jdbcType="INTEGER" property="rowId" /><result column="user_code" jdbcType="VARCHAR" property="userCode" /><result column="user_name" jdbcType="VARCHAR" property="userName" /><result column="pass_word" jdbcType="VARCHAR" property="passWord" /><result column="created_by" jdbcType="VARCHAR" property="createdBy" /><result column="creation_date" jdbcType="TIMESTAMP" property="creationDate" /><result column="last_updated_by" jdbcType="VARCHAR" property="lastUpdatedBy" /><result column="last_update_date" jdbcType="TIMESTAMP" property="lastUpdateDate" /></resultMap><select id="selectList" resultMap="BaseResultMap"parameterType="com.yeqm.demo.entity.TBdUser">select t.* from t_bd_user t</select>
</mapper>

效果

2019-05-30 14:25:39.788  INFO 12228 --- [nio-9990-exec-1] c.y.d.s.DynamicDataSourceContextHolder   : 切换到{master}数据源
2019-05-30 14:25:39.915  INFO 12228 --- [nio-9990-exec-1] com.yeqm.demo.sys.DynamicDataSource      : Current DataSource is master
2019-05-30 14:25:39.917  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2019-05-30 14:25:42.189  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
master
zs
2019-05-30 14:25:43.361  INFO 12228 --- [nio-9990-exec-1] c.y.d.s.DynamicDataSourceContextHolder   : 切换到{salve}数据源
2019-05-30 14:25:43.362  INFO 12228 --- [nio-9990-exec-1] com.yeqm.demo.sys.DynamicDataSource      : Current DataSource is salve
2019-05-30 14:25:43.363  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Starting...
2019-05-30 14:25:44.011  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-2 - Start completed.
salve
we
2019-05-30 14:25:48.393  INFO 12228 --- [nio-9990-exec-1] c.y.d.s.DynamicDataSourceContextHolder   : 切换到{migration}数据源
2019-05-30 14:25:48.394  INFO 12228 --- [nio-9990-exec-1] com.yeqm.demo.sys.DynamicDataSource      : Current DataSource is migration
2019-05-30 14:25:48.394  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-3 - Starting...
2019-05-30 14:25:49.040  INFO 12228 --- [nio-9990-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-3 - Start completed.
migration
sd