spring boot 2.0.1版本，多数据源支持

有时候我们需要在程序中加载多个数据源，用spring jpa可以实现，网上有许多资料，要指定哪个包下面的类使用哪个数据源，个人觉得这种方式不够灵活，不是我想要的。我是想通过多个jdbcTemplate的实例，不同实例操作不同的数据源，甚至不同的实例操作同一类路径的实体对象。下面记录下，实现加载读写分离两个数据源的过程。

pom文件如下：

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.1.RELEASE</version>
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>druid</artifactId>
			<version>1.0.6</version>
		</dependency>
	</dependencies>

application.properties配置文件：

spring.datasource.readwrite.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.readwrite.url=jdbc:mysql://10.1.1.190:3306/ubi?useUnicode=true&characterEncoding=utf-8&autoReconnect=true
spring.datasource.readwrite.username=root
spring.datasource.readwrite.password=park
spring.datasource.readwrite.driver-class-name=com.mysql.jdbc.Driver

spring.datasource.read.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.read.url=jdbc:mysql://10.1.1.190:3306/ubi?useUnicode=true&characterEncoding=utf-8&autoReconnect=true
spring.datasource.read.username=root
spring.datasource.read.password=park
spring.datasource.read.driver-class-name=com.mysql.jdbc.Driver

程序启动时候，加载不同数据源，注入不同的jdbcTemplate实例：

package com.yame.ubi.config;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
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.core.JdbcTemplate;

@Configuration
public class MultiDataSourceConfig {

	@Bean
	@Primary
	@ConfigurationProperties("spring.datasource.readwrite")
	public DataSourceProperties firstDataSourceProperties() {
		return new DataSourceProperties();
	}

	@Bean("dataSource")
	@Primary
	@ConfigurationProperties("spring.datasource.readwrite")
	public DataSource firstDataSource() {
		return firstDataSourceProperties().initializeDataSourceBuilder().build();
	}

	@Bean
	@ConfigurationProperties("spring.datasource.read")
	public DataSourceProperties secondDataSourceProperties() {
		return new DataSourceProperties();
	}

	@Bean(name="readDatasource")
	@ConfigurationProperties("spring.datasource.read")
	public DataSource secondDataSource() {
		return secondDataSourceProperties().initializeDataSourceBuilder().build();
	}
	
    @Bean
    @Primary
    public JdbcTemplate primaryJdbcTemplate(@Qualifier("dataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

    @Bean(name = "readJdbcTemplate")
    public JdbcTemplate secondJdbcTemplate(@Qualifier("readDatasource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }
    
}

声明bean的时候，主数据源强烈建议加上 @Primary注解，同时两个datasource，也要加上bean名称加以区分，否则会报各种各样的错误，如：@Bean("dataSource")和@Bean(name="readDatasource")

使用jdbcTemplate的时候，加上@Qualifier标明使用的是哪个数据源的连接：

package com.yame.ubi.dao;

import java.util.Date;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class MyBeanDao {

	@Autowired
	private JdbcTemplate jdbcTemplate;
	
	@Qualifier("readJdbcTemplate")
	@Autowired
	private JdbcTemplate jdbcTemplateReadOnly;
	
	public Map<String, Object> getRepacket(long id) {
		String sql = "SELECT * FROM ubi_receive_record WHERE id = ?";
		Map<String, Object>  map = jdbcTemplateReadOnly.queryForMap(sql, id);
		return map;
	}
	
	public int update(long userId, int bind) {
		String sql = "update ubi_receive_record set obd_bind = ?, update_time = ? where user_id = ?";
        return jdbcTemplate.update(sql, bind, new Date(), userId);
	}
	
}

  代码：https://github.com/breezylee/lby/tree/master/ubi-cron

（忽略工程里面的定时任务，rabbitmq等配置）