在日常開發中我們可能會用到多數據源開發，什么是多數據源？
簡單來講的話，就是一個項目連接多個數據庫。當然只是可能會用到，我暫時沒見過應用場景，但是還是了解學習一下
此項目可以基於上一個簡單集成項目進行簡單的修改，就能實現多數據源了。
application.yml配置
我們在上一個項目的基礎上進行修改，實現多數據源配置
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://localhost:3306/demo?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
druid:
one:
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/demo?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
initialSize: 5
minIdle: 5
maxActive: 20
initial-size: 3
min-idle: 3
max-active: 10
max-wait: 60000
two:
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/layui?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
initialSize: 5
minIdle: 5
maxActive: 20
initial-size: 6
min-idle: 6
max-active: 20
max-wait: 12000
stat-view-servlet:
login-username: admin
login-password: admin
filter:
stat:
log-slow-sql: true
slow-sql-millis: 2000
mybatis:
mapper-locations: classpath:mappers///Mapper.xml
type-aliases-package: com.ccsert.spdruid..model
configuration:
map-underscore-to-camel-case: true
logging:
file: logs/mass.log
level:
org.springframework: info
com.ccsert: DEBUG
着是完整的配置
主要在druid數據源和mybatis的mapper.xml進行了細微修改
這里我建立一個layui數據庫，里面有個和demo里一樣的表，數據和結構都一樣，方便等會測試
包結構調整，代碼修改
包結構調整
我們先把mapper接口修改一下
在原來的mapper包下建立兩個包，一個one，一個two
然后把之前的mapper接口分別復制到one和two下
然后改一下名字
改完以后大概就是這個樣子
代碼修改
把之前的mapper注解都去掉
后面會用別的方法去映射
這是oneMapper
package com.ccsert.spdruid.test.mapper.one;
import com.ccsert.spdruid.test.model.TestUser;
import java.util.List;
public interface TestUserOneMapper {
List<TestUser> getall();
TestUser getById(Integer id);
int save(TestUser testUser);
}
這是twoMapper
package com.ccsert.spdruid.test.mapper.two;
import com.ccsert.spdruid.test.model.TestUser;
public interface TestUserTwoMapper {
TestUser getById(Integer id);
}
這里為了方便我就只寫一個接口
然后我們在修改一下service實現類
package com.ccsert.spdruid.test.service.impl;
import com.ccsert.spdruid.test.mapper.one.TestUserOneMapper;
import com.ccsert.spdruid.test.mapper.two.TestUserTwoMapper;
import com.ccsert.spdruid.test.model.TestUser;
import com.ccsert.spdruid.test.service.TestUserService;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class TestUserServiceImpl implements TestUserService {
@Resource
private TestUserOneMapper testUserOneMapper;
@Resource
private TestUserTwoMapper testUserTwoMapper;
@Override
public List<TestUser> getall() {
return testUserOneMapper.getall();
}
@Override
public TestUser getById(Integer id) {
return testUserTwoMapper.getById(id);
}
@Override
public int save(TestUser testUser) {
return testUserOneMapper.save(testUser);
}
}
getById方法讓他去調用twoMapper
其余的還是讓它去調用原來的接口
配置文件修改
然后我們把xml的位置移動一下
在resources下的mappers下在建立兩個文件夾
一個one
一個two
然后在把之前的TestUser目錄復制兩份到one和two下
把原來的TestUser刪除掉
在把之前的xml名字修改一下
改完以后大概就是這個樣子了
onemapper.xml的內容保持不變
主要寫一下twomapper.xml的save保存方法
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.ccsert.spdruid.test.mapper.two.TestUserTwoMapper" >
<resultMap id="BaseResultMap" type="com.ccsert.spdruid.test.model.TestUser" >
<id column="id" property="Id" />
<result column="user_name" property="userName"/>
<result column="password" property="password" />
</resultMap>
<select id="getById" parameterType="Integer" resultMap="BaseResultMap">
SELECT
id,user_name,password
FROM
test_user
WHERE id=#{id}
</select>
</mapper>
因為這里的mapper接口路徑是修改過的，onemapper.xml要注意一下
多數據源配置
准備工作做好了接着就是配置多數據源了
在test包下建立一個config包，用於存放配置
然后在config包下建立一個MultiDataSourceConfig類
package com.ccsert.spdruid.test.config;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
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 javax.sql.DataSource;
@Configuration
public class MultiDataSourceConfig {
@Primary
@Bean(name = "oneDataSource")
@ConfigurationProperties("spring.datasource.druid.one")
public DataSource dataSourceOne(){
return DruidDataSourceBuilder.create().build();
}
@Bean(name = "twoDataSource")
@ConfigurationProperties("spring.datasource.druid.two")
public DataSource dataSourceTwo(){
return DruidDataSourceBuilder.create().build();
}
}
這里的ConfigurationProperties是獲取的yml或者properties里的值
spring.datasource.druid.one和spring.datasource.druid.two就是我們配置的數據源
Primary只能指定一個為默認數據源，這里指定了one數據庫
在config下建立DataSource1Config類，用於配置數據源one
package com.ccsert.spdruid.test.config;
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.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
@Configuration
@MapperScan(basePackages = "com.ccsert.spdruid.test.mapper.one", sqlSessionTemplateRef = "test1SqlSessionTemplate")
public class DataSource1Config {
@Bean(name = "test1SqlSessionFactory")
@Primary
public SqlSessionFactory testSqlSessionFactory(@Qualifier("oneDataSource") DataSource dataSource) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/one/**/*Mapper.xml"));
return bean.getObject();
}
@Bean(name = "test1TransactionManager")
@Primary
public DataSourceTransactionManager testTransactionManager(@Qualifier("oneDataSource") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "test1SqlSessionTemplate")
@Primary
public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
@MapperScan(basePackages = "com.ccsert.spdruid.test.mapper.one", sqlSessionTemplateRef = "test1SqlSessionTemplate")指定了實體類的路徑，這里就完成了映射，所以不需要在mapper接口上寫@Mapper注解
然后在建立一個DataSource2Config類
內容和上面的差不多
package com.ccsert.spdruid.test.config;
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.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
@Configuration
@MapperScan(basePackages = "com.ccsert.spdruid.test.mapper.two", sqlSessionTemplateRef = "test2SqlSessionTemplate")
public class DataSource2Config {
@Bean(name = "test2SqlSessionFactory")
public SqlSessionFactory testSqlSessionFactory(@Qualifier("twoDataSource") DataSource dataSource) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/two/**/*Mapper.xml"));
return bean.getObject();
}
@Bean(name = "test2TransactionManager")
public DataSourceTransactionManager testTransactionManager(@Qualifier("twoDataSource") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "test2SqlSessionTemplate")
public SqlSessionTemplate testSqlSessionTemplate(@Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
注意這兩個路徑寫成自己的不要搞錯了
到這里就配置完成了
測試使用
我們先訪問一下接口能否調通
啟動項目然后使用谷歌插件訪問接口
可以看到我們兩個接口都調用成功
我們去druid的監控界面查看一下執行的sql和數據源信息
可以看到druid監控了我們執行的兩條sql，以及兩個數據源信息