动态多数据源配置

动态多数据源配置

方法一：使用注解的方式，在pom文件中加入依赖

        
            com.alibaba
            druid-spring-boot-starter
            1.1.18
        

        
        
            com.baomidou
            dynamic-datasource-spring-boot-starter
            3.2.1
        

        
            mysql
            mysql-connector-java
        

        
            com.baomidou
            mybatis-plus-boot-starter
            3.4.0
        

在application.yml文件中配置数据源

spring:
  datasource:
    dynamic:
      primary: master #设置默认的数据源或者数据源组,默认值即为master
      strict: false #设置严格模式,默认false不启动. 启动后在未匹配到指定数据源时候会抛出异常,不启动则使用默认数据源.
      datasource:
        master:   #配置主库
          url: jdbc:mysql://ip:3306/database?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true
          username: root
          password: 123456
          driver-class-name: com.mysql.cj.jdbc.Driver
        slave_1:    #配置从库
          url: jdbc:mysql://ip:3306/database?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true
          username: root
          password: 123456
          driver-class-name: com.mysql.cj.jdbc.Driver
        slave_2:    #配置从库
          url: jdbc:mysql://ip:3306/database?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true
          username: root
          password: 123456
          driver-class-name: com.mysql.cj.jdbc.Driver

mybatis-plus:
  mapper-locations: classpath:mappers/*.xml
  configuration:
      map-underscore-to-camel-case: true #开启驼峰映射
      #打印SQL信息
      log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

创建测试相关的文件，目录如下

使用 @DS("slave_1") 完成数据库的指定，可以在实现方法上，也可以在dao上使用

在实现方法上，则该方法内的数据库访问都会是指定的数据库

import com.baomidou.dynamic.datasource.annotation.DS;
import com.example.demo.dao.TestDao;
import com.example.demo.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class TestServiceImp implements TestService {
    @Autowired
    private TestDao testDao;
    @Override
    public String queryById() {
        String s = testDao.queryById();
        return s;
    }

    @Override
    @DS("slave_1")
    public String queryById2() {
        String s = testDao.queryById2();
        return s;
    }

    @Override
    public String queryById3() {
        String s = testDao.queryById3();
        return s;
    }
}

在dao上使用，只有用该方法，才会到指定数据库

import com.baomidou.dynamic.datasource.annotation.DS;
import org.apache.ibatis.annotations.Select;

public interface TestDao {

    String queryById();


    String queryById2();


    @DS("slave_2")
    String queryById3();
}

 方法二：yml文件定义两个数据源，然后创建两个config文件扫描不同的路径

import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
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.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.dao2", sqlSessionTemplateRef  = "secondarySqlSessionTemplate")
public class DataSources2Config {

    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource testDataSource() {
        return new DruidDataSource();
    }



    @Bean(name = "secondarySqlSessionFactory")
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("secondaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);

        //添加 驼峰命名法 映射
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        bean.setConfiguration(configuration);
        return bean.getObject();
    }

    @Bean(name = "secondaryTransactionManager")
    public DataSourceTransactionManager testTransactionManager(@Qualifier("secondaryDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "secondarySqlSessionTemplate")
    public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("secondarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}


package com.intehel.common.config.datasource;

import com.alibaba.druid.pool.DruidDataSource;
import com.github.pagehelper.PageInterceptor;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

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

@Configuration
@MapperScan(basePackages = "com.dao", sqlSessionTemplateRef  = "primarySqlSessionTemplate")
public class DataSources1Config {

    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    @Primary
    public DataSource testDataSource() {
        return new DruidDataSource();
    }


    @Bean(name = "primarySqlSessionFactory")
    @Primary
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("primaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //添加 驼峰命名法 映射
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        bean.setConfiguration(configuration);
//bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml"));


        Interceptor interceptor = new PageInterceptor();
        Properties properties = new Properties();
        //数据库
        properties.setProperty("helperDialect", "mysql");
        //是否将参数offset作为PageNum使用
        properties.setProperty("offsetAsPageNum", "true");
        //是否进行count查询
        properties.setProperty("rowBoundsWithCount", "true");
        //是否分页合理化
        properties.setProperty("reasonable", "false");
        interceptor.setProperties(properties);

        return bean.getObject();
    }

    @Bean(name = "primaryTransactionManager")
    @Primary
    public DataSourceTransactionManager testTransactionManager(@Qualifier("primaryDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "primarySqlSessionTemplate")
    @Primary
    public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("primarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}