记一次springboot2.1.6配置（mysql）多数据源

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>8.0.16</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <!--<exclusions>-->
                <!--<exclusion>-->
                    <!--<groupId>org.springframework.boot</groupId>-->
                    <!--<artifactId>spring-boot-starter-tomcat</artifactId>-->
                <!--</exclusion>-->
            <!--</exclusions>-->
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/druid-spring-boot-starter -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.22</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.9.7</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.7</version>
        </dependency>


    </dependencies>



    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

项目结构图

yml文件

server:
  port: 8086

mybatis:
  mapperLocations: classpath*:mapper/*.xml

local:
  host: localhost
  port: 3306
  taosEnable: false

spring:
  datasource:
    db1:
      jdbc-url: jdbc:mysql://${local.host}:${local.port}/tb1?useUnicode=true&characterEncoding=gbk&autoReconnect=true&serverTimezone=Asia/Shanghai&useSSL=false&autoReconnectForPools=true
      username: root
      password: 123456
      driver-class-name: com.mysql.cj.jdbc.Driver
      #最小连接数
      minIdle: 5
      #最大连接数
      maxActive: 500
      #初始化连接数
      initialSize: 5
      #当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3
      acquireIncrement: 5
      #连接关闭时默认将所有未提交的操作回滚。Default: false
      autoCommitOnClose: false
      test-on-borrow: false
      test-on-return: false
      test-while-idle: true
      validation-query: select 1;
      validation-query-timeout: 5000
      #最大空闲时间,30秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0
      maxIdleTime: 30
      #获取连接失败将会引起所有等待连接池来获取连接的线程抛出异常。但是数据源仍有效 保留，并在下次调用getConnection()的时候继续尝试获取连接。
      #如果设为true，那么在尝试 获取连接失败后该数据源将申明已断开并永久关闭。Default:false
      breakAfterAcquireFailure: false
    db2:
      jdbc-url: jdbc:mysql://${local.host}:${local.port}/tb2?useUnicode=true&characterEncoding=gbk&autoReconnect=true&serverTimezone=Asia/Shanghai&useSSL=false&autoReconnectForPools=true
      username: root
      password: 123456
      driver-class-name: com.mysql.cj.jdbc.Driver
      #最小连接数
      minIdle: 5
      #配置SQL拦截
      filters: stat
      #最大连接数
      maxActive: 500
      #初始化连接数
      initialSize: 5
      #当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3
      acquireIncrement: 5
      #连接关闭时默认将所有未提交的操作回滚。Default: false
      autoCommitOnClose: true
      test-on-borrow: false
      test-on-return: false
      test-while-idle: true
      validation-query: select 1;
      validation-query-timeout: 5000
      poolPreparedStatements: true
      #最大空闲时间,30秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0
      maxIdleTime: 30
      #获取连接失败将会引起所有等待连接池来获取连接的线程抛出异常。但是数据源仍有效 保留，并在下次调用getConnection()的时候继续尝试获取连接。
      #如果设为true，那么在尝试 获取连接失败后该数据源将申明已断开并永久关闭。Default:false
      breakAfterAcquireFailure: false
    db3:
      jdbc-url: jdbc:mysql://${local.host}:${local.port}/tb3?useUnicode=true&characterEncoding=gbk&autoReconnect=true&serverTimezone=Asia/Shanghai&useSSL=false&autoReconnectForPools=true
      username: root
      password: 123456
      driver-class-name: com.mysql.cj.jdbc.Driver
      #最小连接数
      minIdle: 5
      #配置SQL拦截
      filters: stat
      #最大连接数
      maxActive: 500
      #初始化连接数
      initialSize: 5
      #当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3
      acquireIncrement: 5
      #连接关闭时默认将所有未提交的操作回滚。Default: false
      autoCommitOnClose: true
      test-on-borrow: false
      test-on-return: false
      test-while-idle: true
      validation-query: select 1;
      validation-query-timeout: 5000
      poolPreparedStatements: true
      #最大空闲时间,30秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0
      maxIdleTime: 30
      #获取连接失败将会引起所有等待连接池来获取连接的线程抛出异常。但是数据源仍有效 保留，并在下次调用getConnection()的时候继续尝试获取连接。
      #如果设为true，那么在尝试 获取连接失败后该数据源将申明已断开并永久关闭。Default:false
      breakAfterAcquireFailure: false

mapper.xml、dao、service、serviceImpl这些就不看了，跟单数据源一样

1、创建一个自定义注解

package com.example.demo.annotation;

import java.lang.annotation.*;

@Documented
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
public @interface DataSource {

    String value();
}

2、创建一个apo切面

package com.example.demo.config;

import com.example.demo.annotation.DataSource;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

@Component
@Aspect
public class DataSourceConfig {

    @Before("@annotation(dataSource)")
    public void beforeSwitchDataSource(DataSource dataSource) {
        DynamicDataSource.changeDataSource(dataSource.value());
    }

    @After("@annotation(com.example.demo.annotation.DataSource)")
    public void afterSwitchDataSource() {
        DynamicDataSource.clearDataSource();
    }
}

3、引入了配置信息之后，便是该说如何实现多数据源切换了。我们是通过实现AbstractRoutingDataSource类的determineCurrentLookupKey方法来实现数据源的动态路由，设置ThreadLocal线程保护变量存储数据源key，确保线程间不受影响。

package com.example.demo.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * @author lazycece
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
    private static final Logger LOGGER = LoggerFactory.getLogger(DynamicDataSource.class);

    private static final ThreadLocal<String> DATA_SOURCE_KEY = new ThreadLocal<>();

    static void changeDataSource(String dataSourceKey) {
        DATA_SOURCE_KEY.set(dataSourceKey);
    }

    static void clearDataSource() {
        DATA_SOURCE_KEY.remove();
    }

    @Override
    protected Object determineCurrentLookupKey() {
        String key = DATA_SOURCE_KEY.get();
        LOGGER.info("切换数据源为: {}", key);
        return key;
    }
}

4、java配置数据源

package com.example.demo.config;

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


@Configuration
public class MultiDataSource {

    public static final String TB1 = "tb1";
    public static final String TB2 = "tb2";
    public static final String TB3 = "tb3";

    @Bean(name = MultiDataSource.TB1)
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource tb1() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = MultiDataSource.TB2)
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource tb2() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = MultiDataSource.TB3)
    @ConfigurationProperties(prefix = "spring.datasource.db3")
    public DataSource tb3() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean(name = "dynamicDataSource")
    public DynamicDataSource dataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        dynamicDataSource.setDefaultTargetDataSource(tb1());
        Map<Object, Object> dataSourceMap = new HashMap<>(4);
        dataSourceMap.put(TB1, tb1());
        dataSourceMap.put(TB2, tb2());
        dataSourceMap.put(TB3, tb3());
        dynamicDataSource.setTargetDataSources(dataSourceMap);
        return dynamicDataSource;
    }
}

最最主要的是：在service的实现类上面加上注解，下面看我是怎么加的 

完事了 ，直接启动，请求：

 项目引入jar包图

这个是我自己经过网上东拼西凑，所得的结果，因为网上别人说的不怎么全，现在自己弄出来想记录一下。如果对你们有帮助，那我写这个就更加有意义了