5步配置Springboot+Mybatisplus+druid 实现配置多数据源

在做springboot项目中，会用到多个库，借助于druid连接池实现配置多个数据库表 

1.pom文件

    4.0.0

    bj.cy.aj
    Workpase
    1.0-SNAPSHOT

    
        org.springframework.boot
        spring-boot-starter-parent
        1.5.1.RELEASE
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.4.3
        
        
            mysql
            mysql-connector-java
            8.0.11
        
        
            com.baomidou
            mybatis-plus-core
            3.4.3.1
        
        
            com.alibaba
            fastjson
            1.2.56
        
        
            com.mchange
            c3p0
            0.9.5.5
        

        
            com.alibaba
            druid
            1.2.3
        

        
        
            com.baomidou
            mybatis-plus-extension
            3.4.3.1
        

        
        
            com.baomidou
            dynamic-datasource-spring-boot-starter
            3.5.1
        


        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.21
        

    

2.在yml文件中配置

server:
    port: 8081


## druid连接池配置
spring:
    datasource:
        dynamic:
            #默认数据源
            primary: master
            datasource:
                # 主库配置 master
                master:
                    username: root
                    password: xxxx
                    driver-class-name: com.mysql.cj.jdbc.Driver
                    url: xxxxxxxxxxxxxxxxxxxxxxxx
                    initial-size: 1
                    max-active: 10
                    min-idle: 1
                    max-wait: 60000
                    pool-prepared-statements: true
                    max-pool-prepared-statement-per-connection-size: 5
                    time-between-eviction-runs-millis: 60000
                    min-evictable-idle-time-millis: 300000
                    test-while-idle: true
                    test-on-borrow: false
                    test-on-return: false
                    stat-view-servlet:
                        enabled: true
                        url-pattern: /druid/*
                    filter:
                        stat:
                            log-slow-sql: true
                            slow-sql-millis: 1000
                            merge-sql: false
                        wall:
                            config:
                                multi-statement-allow: true
                # 从库配置 slave
                slave:
                    username: root
                    password: root
                    driver-class-name: com.mysql.cj.jdbc.Driver
                    url: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                    initial-size: 1
                    max-active: 10
                    min-idle: 1
                    max-wait: 60000
                    pool-prepared-statements: true
                    max-pool-prepared-statement-per-connection-size: 5
                    time-between-eviction-runs-millis: 60000
                    min-evictable-idle-time-millis: 300000
                    test-while-idle: true
                    test-on-borrow: false
                    test-on-return: false
                    stat-view-servlet:
                        enabled: true
                        url-pattern: /druid/*
                    filter:
                        stat:
                            log-slow-sql: true
                            slow-sql-millis: 1000
                            merge-sql: false
                        wall:
                            config:
                                multi-statement-allow: true

3.新建  DataSourceContextHolder类

package bj.cy.aj.Config;

/**
 * @desc  建立DataSourceContextHolder类
 */
public class DataSourceContextHolder {
    private static final ThreadLocal contextHolder = new InheritableThreadLocal();

    /**
     *  设置数据源
     * @param db
     */
    public static void setDataSource(String db){
        contextHolder.set(db);
    }

    /**
     * 取得当前数据源
     * @return
     */
    public static String getDataSource(){
        return contextHolder.get();
    }

    /**
     * 清除上下文数据
     */
    public static void clear(){
        contextHolder.remove();
    }
}

4.主库和从库已经配置好了

如果想在service中切换数据库使用注解

@DS("slave")

即可切换数据库

5.在启动注解配置

@SpringBootApplication(exclude = DruidDataSourceAutoConfigure.class)