动态添加移除数据源

基础准备

在Java中，使用dynamic-datasource可以动态地添加或移除数据源。以下是一个使用dynamic-datasource的简单示例：

首先，添加dynamic-datasource的依赖到你的项目中，例如使用Maven：

<dependency>  
	<groupId>com.baomidou</groupId>  
	<artifactId>dynamic-datasource-spring-boot-starter</artifactId>  
</dependency>

然后，在配置文件中定义主数据源和默认数据源：

spring:
  datasource:
    dynamic:
      primary: master # 设置主数据源的名称
      datasource:
        master:
          url: jdbc:mysql://localhost:3306/master
          username: master_user
          password: master_password
        slave_1:
          url: jdbc:mysql://localhost:3306/slave_1
          username: slave_1_user
          password: slave_1_password

接下来，你可以在代码中动态添加或移除数据源。

动态增加 DataSource，依靠 DynamicRoutingDataSource提供的 addDataSource() 和 removeDataSource() 方法，实现数据源动态的添加和移除。

创建 DataSource，使用 DataSourceCreator接口的实现类来创建数据源。 DefaultDataSourceCreator：通用数据源创建器，其根据环境自动选择连接池 BasicDataSourceCreator：调用 Spring 原生的创建方式，只支持最原始的基础配置 HikariDataSourceCreator：创建 HikariDataSource DruidDataSourceCreator：创建 DruidDataSource

简单实现1

import com.baomidou.dynamic.datasource.DynamicRoutingDataSource;
import com.baomidou.dynamic.datasource.creator.DynamicDataSourceCreator;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DataSourceProperty;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
 
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
 
@Configuration
public class DynamicDataSourceConfig {
 
    @Autowired
    private DynamicRoutingDataSource dynamicRoutingDataSource;
 
    @Bean
    @Primary
    public DataSource dataSource() {
        return dynamicRoutingDataSource;
    }
 
    public void addDataSource(String dsName, DataSourceProperty dataSourceProperty) {
        DynamicDataSourceCreator dataSourceCreator = new DynamicDataSourceCreator(dataSourceProperty);
        DataSource dataSource = dataSourceCreator.createDataSource();
        dynamicRoutingDataSource.putDataSource(dsName, dataSource);
    }
 
    public void removeDataSource(String dsName) {
        dynamicRoutingDataSource.removeDataSource(dsName);
    }
}

简单实现2

//3.4.0版本以下
@Primary
@Bean
public DataSource dataSource(DynamicDataSourceProvider dynamicDataSourceProvider) { 
    DynamicRoutingDataSource dataSource = new DynamicRoutingDataSource();
    dataSource.setPrimary(properties.getPrimary());
    dataSource.setStrict(properties.getStrict());
    dataSource.setStrategy(properties.getStrategy());
    dataSource.setProvider(dynamicDataSourceProvider);
    dataSource.setP6spy(properties.getP6spy());
    dataSource.setSeata(properties.getSeata());
    return dataSource;
}

//3.4.0版本及以上
@Primary
@Bean
public DataSource dataSource() {
    DynamicRoutingDataSource dataSource = new DynamicRoutingDataSource();
    dataSource.setPrimary(properties.getPrimary());
    dataSource.setStrict(properties.getStrict());
    dataSource.setStrategy(properties.getStrategy());
    dataSource.setP6spy(properties.getP6spy());
    dataSource.setSeata(properties.getSeata());
    return dataSource;
}

主要变更是因为3.4.0支持了多个provider同时生效，采取了内部注入。 源码改动参考 https://github.com/baomidou/dynamic-datasource-spring-boot-starter/commit/6e8d2954499f83269302d23b58f8832c31e07ef7

复杂示例，使用DataSourceCreator构造dataSource

使用API和配置项来添加、移除数据源。

import com.baomidou.dynamic.datasource.DynamicRoutingDataSource;
import com.baomidou.dynamic.datasource.creator.*;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DataSourceProperty;
import com.baomidou.samples.ds.dto.DataSourceDTO;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

import javax.sql.DataSource;
import java.util.Set;

@RestController
@RequestMapping("/datasources")
@Api(tags = "添加删除数据源")
public class DataSourceController {

    @Autowired
    private DataSource dataSource;
   // private final DataSourceCreator dataSourceCreator; //3.3.1及以下版本使用这个通用，强烈推荐sb2用户至少升级到3.5.2版本

    @Autowired
    private DefaultDataSourceCreator dataSourceCreator;
//如果是用4.x以上版本，因为要和spring解绑，重构了一些东西，比如缺少了懒启动和启动初始化数据库。不太建议用以下独立的创建器，只建议用上面的DefaultDataSourceCreator 
    @Autowired
    private BasicDataSourceCreator basicDataSourceCreator;
    @Autowired
    private JndiDataSourceCreator jndiDataSourceCreator;
    @Autowired
    private DruidDataSourceCreator druidDataSourceCreator;
    @Autowired
    private HikariDataSourceCreator hikariDataSourceCreator;
    @Autowired
    private BeeCpDataSourceCreator beeCpDataSourceCreator;
    @Autowired
    private Dbcp2DataSourceCreator dbcp2DataSourceCreator;

    @GetMapping
    @ApiOperation("获取当前所有数据源")
    public Set<String> now() {
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        return ds.getDataSources().keySet();
    }

    //通用数据源会根据maven中配置的连接池根据顺序依次选择。
    //默认的顺序为druid>hikaricp>beecp>dbcp>spring basic
    @PostMapping("/add")
    @ApiOperation("通用添加数据源（推荐）")
    public Set<String> add(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = dataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addBasic(强烈不推荐，除了用了马上移除)")
    @ApiOperation(value = "添加基础数据源", notes = "调用Springboot内置方法创建数据源，兼容1,2")
    public Set<String> addBasic(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = basicDataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addJndi")
    @ApiOperation("添加JNDI数据源")
    public Set<String> addJndi(String pollName, String jndiName) {
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = jndiDataSourceCreator.createDataSource(jndiName);
        ds.addDataSource(poolName, dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addDruid")
    @ApiOperation("基础Druid数据源")
    public Set<String> addDruid(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        dataSourceProperty.setLazy(true);
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = druidDataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addHikariCP")
    @ApiOperation("基础HikariCP数据源")
    public Set<String> addHikariCP(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        dataSourceProperty.setLazy(true);//3.4.0版本以下如果有此属性，需手动设置，不然会空指针。
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = hikariDataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addBeeCp")
    @ApiOperation("基础BeeCp数据源")
    public Set<String> addBeeCp(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        dataSourceProperty.setLazy(true);//3.4.0版本以下如果有此属性，需手动设置，不然会空指针。
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = beeCpDataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @PostMapping("/addDbcp")
    @ApiOperation("基础Dbcp数据源")
    public Set<String> addDbcp(@Validated @RequestBody DataSourceDTO dto) {
        DataSourceProperty dataSourceProperty = new DataSourceProperty();
        BeanUtils.copyProperties(dto, dataSourceProperty);
        dataSourceProperty.setLazy(true);//3.4.0版本以下如果有此属性，需手动设置，不然会空指针。
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        DataSource dataSource = dbcp2DataSourceCreator.createDataSource(dataSourceProperty);
        ds.addDataSource(dto.getPoolName(), dataSource);
        return ds.getDataSources().keySet();
    }

    @DeleteMapping
    @ApiOperation("删除数据源")
    public String remove(String name) {
        DynamicRoutingDataSource ds = (DynamicRoutingDataSource) dataSource;
        ds.removeDataSource(name);
        return "删除成功";
    }
}

接收对象

@Data
public class DataSourceDTO {

    /**
     * 连接池名称
     */
    private String poolName;

    /**
     * JDBC driver org.h2.Driver
     */
    private String driverClassName;

    /**
     * JDBC url 地址
     */
    private String url;

    /**
     * JDBC 用户名
     */
    private String username;

    /**
     * JDBC 密码
     */
    private String password;
}