SpringBoot整合JDBC数据库操作-9:配置多DataSource/Transactional

上篇文章我们讲到了使用代码注入DataSource,这篇文章主要讲解一下在项目中配置多DataSource和启用Transactional事务.

将application.yml配置文件加入以下内容

custom-second:
  source:
    driver: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test1
    username: root
    password: 123456

在源码目录下新建config目录, 在该目录下新建CustomSecondDataSource类文件

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.edurt.config;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcTemplate;

import javax.sql.DataSource;

/**
 * CustomSecondDataSource <br/>
 * 描述 : CustomSecondDataSource <br/>
 * 作者 : qianmoQ <br/>
 * 版本 : 1.0 <br/>
 * 创建时间 : 2018-03-29 下午1:29 <br/>
 * 联系作者 : <a href="mailTo:shichengoooo@163.com">qianmoQ</a>
 */
@Configuration
public class CustomSecondDataSource {

    @Bean(name = "secondDatasource")
    @ConfigurationProperties(prefix = "custom-second.source")
    public DataSource secondDataSource() {
        return DataSourceBuilder.create().build();
    }

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

}

注意secondJdbcTemplate在创建时，传入的DataSource必须用@Qualifier("secondDatasource")声明，这样，才能使用第二个DataSource。

将CustomDataSource文件中的dataSource和jdbcTemplate标记为主要的, 修改为以下内容

@Bean
@Primary
public DataSource dataSource() {
    return DataSourceBuilder.create()
            .driverClassName(driver)
            .url(url)
            .username(username)
            .password(password).build();
}

@Bean
@Primary
public JdbcTemplate jdbcTemplate() {
    return new JdbcTemplate(dataSource());
}

在repository文件夹下创建SecondRepository用于测试第二个datasource

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.edurt.repository;

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

/**
 * SecondRepository <br/>
 * 描述 : SecondRepository <br/>
 * 作者 : qianmoQ <br/>
 * 版本 : 1.0 <br/>
 * 创建时间 : 2018-03-29 下午1:35 <br/>
 * 联系作者 : <a href="mailTo:shichengoooo@163.com">qianmoQ</a>
 */
@Component
public class SecondRepository {

    @Autowired
    @Qualifier("secondJdbcTemplate")
    // 在需要使用第二个JdbcTemplate的地方，我们注入时需要用@Qualifier("secondJdbcTemplate")标识
    private JdbcTemplate jdbcTemplate;

    public int save(int i) {
        return jdbcTemplate.update("INSERT INTO a(id) VALUES (?)", i);
    }

}

修改ArticleController对外接口类

@Autowired
private SecondRepository secondRepository;

@RequestMapping(value = "test", method = RequestMethod.POST)
int test(@RequestParam Integer id) {
    return secondRepository.save(id);
}

多个DataSource，多个JdbcTemplate时，强烈建议总是使用@Primary把其中某一个Bean标识为“主要的”，使用@Autowired注入时会首先使用被标记为@Primary的Bean

启用Transactional的话我们只需要将**@EnableTransactionManagement增加到项目的启动类中和将@Transactional**注解增加到我们要做事务的方法上即可