Spring boot integrates Dubbo Nacos druid to realize dynamic data source switching

Subject: Spring boot Integrated dubbo nacos druid realizes dynamic switching of data sources

I. experimental purpose

Spring boot Integrated dubbo nacos druid realizes dynamic data source switching. After changing the configuration of nacos, it can dynamically switch data sources without restarting the springboot application.

two Implementation solutions

Principle analysis: after spring boot integrates druid data source, we can

DruidDataSource master = SpringUtil.getBean(DruidDataSource.class);

1. Get the current DruidDataSource object,

2. Through @ nacosvalue, we can get the configuration changes in nacos and get the changed connection information immediately.

3. Use The restart() method provided by the DruidDataSource object can directly reset the database connection information, so as to achieve dynamic data source switching.

4. The last step is when to execute the restart() method. Time is very important and necessary. By reading the source code of nacos dubbo integration, you can find that there is an annotation for event listening

three Achieve the most important step 4.

use @ NacosConfigListener Annotation to monitor the corresponding configuration changes. At this time, you can switch the connection information of the database. The specific implementation code is as follows.

package com.study.cloud.springbootdubbo;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.nacos.api.annotation.NacosInjected;
import com.alibaba.nacos.api.config.ConfigChangeEvent;
import com.alibaba.nacos.api.config.annotation.NacosConfigListener;
import com.alibaba.nacos.api.config.annotation.NacosValue;
import com.alibaba.nacos.spring.context.event.config.NacosConfigEvent;
import com.alibaba.nacos.spring.context.event.config.NacosConfigPublishedEvent;
import com.purgeteam.dynamic.config.starter.event.ActionConfigEvent;
import com.study.cloud.springbootdubbo.config.DruidConfiguration;
import com.study.cloud.springbootdubbo.util.SpringUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;

import java.sql.SQLException;
import java.util.Properties;

/**
 * Automatically monitor the changes of druidconfig.yml in nacos, and then restart the data source
 */
@Slf4j
@Component
public class MyNacosEventListener   {

    @Autowired
    DruidConfiguration druidConfiguration;

    @NacosValue(value = "${spring.datasource.druid.url}", autoRefreshed = true)
    private String url;

    @NacosConfigListener(dataId = "druidconfig.yml", groupId = "DEFAULT_GROUP")
    public void onReceived(String content) throws SQLException {
        log.info("onReceived(String) : {}", content);
        DruidDataSource master = SpringUtil.getBean(DruidDataSource.class);
        master.setUrl(druidConfiguration.getUrl());
        master.setUsername(druidConfiguration.getUsername());
        master.setPassword(druidConfiguration.getPassword());
        master.setDriverClassName(druidConfiguration.getDriverClassName());
        master.restart();
        String msg= master.getUsername() + "<>" + master.getUrl()+"----------"+master.getPassword();
        System.out.println(msg);
    }

}

The configuration information of nacos is as follows:

4, Experimental results

When we change the connection information about the database in nacos, such as url or user name and password, the data source of the application will automatically switch to the corresponding server DB for operation.

1. postman sends a request to see the result.