spring boot (spring data jpa多数据源配置①)

1、配置数据库的链接属性

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package com.example.song.config;

import java.sql.SQLException;

import javax.sql.DataSource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import com.alibaba.druid.pool.DruidDataSource;

/**
* @ClassName: DruidDBConfig
* @Description: 设置数据库的链接属性
* @author songyunfei
* @date 2018年6月26日 下午3:51:53
*
*/
@ServletComponentScan
@Configuration
public class DruidDBConfig {

private Logger logger=LoggerFactory.getLogger(DruidDBConfig.class);
@Value("${spring.datasource.primary.url}")
private String dbUrl1;

@Value("${spring.datasource.primary.username}")
private String username1;

@Value("${spring.datasource.primary.password}")
private String password1;

@Value("${spring.datasource.secondary.url}")
private String dbUrl2;

@Value("${spring.datasource.secondary.username}")
private String username2;

@Value("${spring.datasource.secondary.password}")
private String password2;

@Value("com.mysql.jdbc.Driver")
private String driverClassName;

@Value("5")
private int initialSize;

@Value("5")
private int minIdle;

@Value("20")
private int maxActive;

@Value("60000")
private int maxWait;

/**
* 配置间隔多久才进行一次检测，检测须要关闭的空闲链接，单位是毫秒
*/
@Value("60000")
private int timeBetweenEvictionRunsMillis;

/**
* 配置一个链接在池中最小生存的时间，单位是毫秒
*/
@Value("300000")
private int minEvictableIdleTimeMillis;

@Value("SELECT 1 FROM DUAL")
private String validationQuery;

@Value("true")
private boolean testWhileIdle;

@Value("false")
private boolean testOnBorrow;

@Value("false")
private boolean testOnReturn;

/**
* 打开PSCache，而且指定每一个链接上PSCache的大小
*/
@Value("true")
private boolean poolPreparedStatements;

@Value("20")
private int maxPoolPreparedStatementPerConnectionSize;
/**
* 配置监控统计拦截的filters，去掉后监控界面sql没法统计，'wall'用于防火墙
*/
@Value("stat,wall,log4j")
private String filters;

/**
* 经过connectProperties属性来打开mergeSql功能；慢SQL记录
*/
@Value("druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500")
private String connectionProperties;

@Bean(name = "primaryDataSource")
@Qualifier("primaryDataSource")
public DataSource dataSource() {
return getDruidDataSource(username1, password1, dbUrl1);
}

@Bean(name = "secondaryDataSource")
@Qualifier("secondaryDataSource") //设置注入bean的名称spring容器在注入经过byname 而不是bytype
@Primary
public DataSource secondaryDataSource() {
return getDruidDataSource(username2, password2, dbUrl2);
}

private DruidDataSource getDruidDataSource(String username, String password, String url) {
DruidDataSource datasource = new DruidDataSource();

datasource.setUrl(url);
datasource.setUsername(username);
datasource.setPassword(password);
datasource.setDriverClassName(driverClassName);

//configuration
datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements);
datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
try {
datasource.setFilters(filters);
} catch (SQLException e) {
logger.error("druid configuration initialization filter : {0}", e);
}
datasource.setConnectionProperties(connectionProperties);

return datasource;
}
}

 

2、主数据源（第一数据源）的配置

package com.example.song.config;

import java.util.Map;

import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef="entityManagerFactoryPrimary",
transactionManagerRef="transactionManagerPrimary",
basePackages={"com.example.song.mapper.primary"})
public class PrimaryConfig {

@Resource
@Qualifier("primaryDataSource")
private DataSource primaryDataSource;

@Primary
@Bean(name = "entityManagerPrimary")
public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
}
@Resource
private JpaProperties jpaProperties;

private Map<String, Object> getVendorProperties() {
return jpaProperties.getHibernateProperties(new HibernateSettings());
}
/**
* 设置实体类的位置
*/
@Primary
@Bean(name="entityManagerFactoryPrimary")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder){
return builder.dataSource(primaryDataSource)
.packages("com.example.song.domain.primary")
.persistenceUnit("primaryPersistenceUnit")
.properties(getVendorProperties())
.build();
}
@Primary
@Bean(name="transactionManagerPrimary")
public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder){
return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
}
}

3、第二数据源的配置

package com.example.song.config;

import java.util.Map;

import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

/**
*
* @ClassName: SecondaryDataSource
* @Description: 第二数据源的配置
* @author songyunfei
* @date 2018年6月26日 下午4:13:11
*
*/
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories( entityManagerFactoryRef = "entityManagerFactorySecondary",
transactionManagerRef = "transactionManagerSecondary",
basePackages = {"com.example.song.mapper.scondary"})
public class SecondaryConfig {

@Resource
@Qualifier("secondaryDataSource")
private DataSource secondaryDataSource;

@Bean(name = "entityManagerSecondary")
public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
return entityManagerFactorySecondary(builder).getObject().createEntityManager();
}
@Resource
private JpaProperties jpaProperties;

private Map<String, Object> getVendorProperties() {
return jpaProperties.getHibernateProperties(new HibernateSettings());
}
/**
* 设置实体类的位置
*/
@Bean(name="entityManagerFactorySecondary")
public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder){
return builder.dataSource(secondaryDataSource)
.packages("com.example.song.domain.secondary")
.persistenceUnit("secondaryPersistenceUnit")
.properties(getVendorProperties())
.build();
}
@Bean(name="transactionManagerSecondary")
public PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder){
return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
}
}

 

总结：以上代码也是从网上其余的网友哪里copy过来，本身改了点配置，很是感谢其余网友的贡献

          程序如今正常运行，可是仍是有问题如今不是很清楚

       ①若是一个service中调用了两个数据源，那么事物怎么控制,本身写的demo中发现不一样的数据源，一个数据源出错，仍是会回滚的

       ②在实际的环境中，多数据源的使用会有哪些问题，目前咱们公司尚未使用到多数据源