springboot2.0 动态切换多数据源

一、引入依赖

            org.springframework.boot
            spring-boot-starter-aop
       

二、编辑application.yml

#数据源配置（默认）
#useSSL=false MySQL在高版本需要指明是否进行SSL连接（不加第一次连接数据库会有警告信息）
spring.datasource.driver=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
#ds1,ds2 其他两个数据源
slave.datasource.names=ds1,ds2
#ds1
slave.datasource.ds1.driver=com.mysql.jdbc.Driver
slave.datasource.ds1.url=jdbc:mysql://localhost:3306/test1?useSSL=false
slave.datasource.ds1.username=root
slave.datasource.ds1.password=123456
#ds2
slave.datasource.ds2.driver=com.mysql.jdbc.Driver
slave.datasource.ds2.url=jdbc:mysql://localhost:3306/test2?useSSL=false
slave.datasource.ds2.username=root
slave.datasource.ds2.password=123456

三、DataSource工具类

动态切换类

package com.chaoqi.springboot_datasource.config;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * @Description 动态数据源
 * AbstractRoutingDataSource(每执行一次数据库，动态获取DataSource)
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}

动态数据源上下文管理 

package com.chaoqi.springboot_datasource.config;

import org.apache.log4j.Logger;

import java.util.ArrayList;
import java.util.List;

/**
 * @Description 动态数据源上下文管理
 */
public class DynamicDataSourceContextHolder {

    private Logger logger = Logger.getLogger(DynamicDataSourceContextHolder.class);
    //存放当前线程使用的数据源类型信息
    private static final ThreadLocal contextHolder = new ThreadLocal();
    //存放数据源id
    public static List dataSourceIds = new ArrayList();

    //设置数据源
    public static void setDataSourceType(String dataSourceType) {
        contextHolder.set(dataSourceType);
    }

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

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

    //判断当前数据源是否存在
    public static boolean isContainsDataSource(String dataSourceId) {
        return dataSourceIds.contains(dataSourceId);
    }
} 

初始化数据源和提供了执行动态切换数据源的工具类

package com.chaoqi.springboot_datasource.config;

import org.apache.log4j.Logger;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotationMetadata;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @Description 注册动态数据源
 * 初始化数据源和提供了执行动态切换数据源的工具类
 * EnvironmentAware（获取配置文件配置的属性值）
 */

public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware {

    private Logger logger = Logger.getLogger(DynamicDataSourceRegister.class);

    //指定默认数据源(springboot2.0默认数据源是hikari如何想使用其他数据源可以自己配置)
    private static final String DATASOURCE_TYPE_DEFAULT = "com.zaxxer.hikari.HikariDataSource";
    //默认数据源
    private DataSource defaultDataSource;
    //用户自定义数据源
    private Map slaveDataSources = new HashMap<>();

    @Override
    public void setEnvironment(Environment environment) {
        initDefaultDataSource(environment);
        initslaveDataSources(environment);
    }

    private void initDefaultDataSource(Environment env) {
        // 读取主数据源
        Map dsMap = new HashMap<>();
        dsMap.put("driver", env.getProperty("spring.datasource.driver"));
        dsMap.put("url", env.getProperty("spring.datasource.url"));
        dsMap.put("username", env.getProperty("spring.datasource.username"));
        dsMap.put("password", env.getProperty("spring.datasource.password"));
        defaultDataSource = buildDataSource(dsMap);
    }

    private void initslaveDataSources(Environment env) {
        // 读取配置文件获取更多数据源
        String dsPrefixs = env.getProperty("slave.datasource.names");
        for (String dsPrefix : dsPrefixs.split(",")) {
            // 多个数据源
            Map dsMap = new HashMap<>();
            dsMap.put("driver", env.getProperty("slave.datasource." + dsPrefix + ".driver"));
            dsMap.put("url", env.getProperty("slave.datasource." + dsPrefix + ".url"));
            dsMap.put("username", env.getProperty("slave.datasource." + dsPrefix + ".username"));
            dsMap.put("password", env.getProperty("slave.datasource." + dsPrefix + ".password"));
            DataSource ds = buildDataSource(dsMap);
            slaveDataSources.put(dsPrefix, ds);
        }
    }

    @Override
    public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry beanDefinitionRegistry) {
        Map targetDataSources = new HashMap();
        //添加默认数据源
        targetDataSources.put("dataSource", this.defaultDataSource);
        DynamicDataSourceContextHolder.dataSourceIds.add("dataSource");
        //添加其他数据源
        targetDataSources.putAll(slaveDataSources);
        for (String key : slaveDataSources.keySet()) {
            DynamicDataSourceContextHolder.dataSourceIds.add(key);
        }

        //创建DynamicDataSource
        GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
        beanDefinition.setBeanClass(DynamicDataSource.class);
        beanDefinition.setSynthetic(true);
        MutablePropertyValues mpv = beanDefinition.getPropertyValues();
        mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
        mpv.addPropertyValue("targetDataSources", targetDataSources);
        //注册 - BeanDefinitionRegistry
        beanDefinitionRegistry.registerBeanDefinition("dataSource", beanDefinition);

        logger.info("Dynamic DataSource Registry");
    }

    public DataSource buildDataSource(Map dataSourceMap) {
        try {
            Object type = dataSourceMap.get("type");
            if (type == null) {
                type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource
            }
            Class dataSourceType;
            dataSourceType = (Class) Class.forName((String) type);
            String driverClassName = dataSourceMap.get("driver").toString();
            String url = dataSourceMap.get("url").toString();
            String username = dataSourceMap.get("username").toString();
            String password = dataSourceMap.get("password").toString();
            // 自定义DataSource配置
            DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
                    .username(username).password(password).type(dataSourceType);
            return factory.build();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }
}

自定义注解

package com.chaoqi.springboot_datasource.config;

import java.lang.annotation.*;

/**
 * @Description 作用于类、接口或者方法上
 */
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource {

    String name();
}

动态数据源通知

package com.chaoqi.springboot_datasource.config;

import org.apache.log4j.Logger;
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.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * @Description 动态数据源通知
 */
@Aspect
@Order(-1)//保证在@Transactional之前执行
@Component
public class DynamicDattaSourceAspect {

    private Logger logger = Logger.getLogger(DynamicDattaSourceAspect.class);

    //改变数据源
    @Before("@annotation(targetDataSource)")
    public void changeDataSource(JoinPoint joinPoint, TargetDataSource targetDataSource) {
        String dbid = targetDataSource.name();

        if (!DynamicDataSourceContextHolder.isContainsDataSource(dbid)) {
            //joinPoint.getSignature() ：获取连接点的方法签名对象
            logger.error("数据源 " + dbid + " 不存在使用默认的数据源 -> " + joinPoint.getSignature());
        } else {
            logger.debug("使用数据源：" + dbid);
            DynamicDataSourceContextHolder.setDataSourceType(dbid);
        }
    }

    @After("@annotation(targetDataSource)")
    public void clearDataSource(JoinPoint joinPoint, TargetDataSource targetDataSource) {
        logger.debug("清除数据源 " + targetDataSource.name() + " !");
        DynamicDataSourceContextHolder.clearDataSourceType();
    }
}

启动类引入DynamicDataSourceRegister

@Import(DynamicDataSourceRegister.class)