原文地址爲:點擊打開鏈接
摘要: Spring Boot最大的特點是簡化開發,因此使用Java Config實現去xml配置,本文將使用這種方式完成對阿里雲ADS和RDS兩個產品的多數據源配置。同時,會用到阿里巴巴的開源數據源Druid。 依賴 因爲ADS和RDS都兼容mysql的JDBC實現,因此工程只需要依賴mysql的dri...
Spring Boot最大的特點是簡化開發,因此使用Java Config實現去xml配置,本文將使用這種方式完成對阿里雲ADS和RDS兩個產品的多數據源配置。同時,會用到阿里巴巴的開源數據源Druid。
依賴
- 因爲ADS和RDS都兼容mysql的JDBC實現,因此工程只需要依賴mysql的driver。
- Spring Boot易用性的特點是通過Starter實現的,我們只需依賴mybatis的spring-boot-starter即可。
- Druid是數據源。
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>${mybatis-spring-boot-starter.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${druid.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql-connector-java.version}</version>
</dependency>
<properties>
<mysql-connector-java.version>5.1.34</mysql-connector-java.version>
<druid.version>1.0.18</druid.version>
<mybatis-spring-boot-starter.version>1.1.1</mybatis-spring-boot-starter.version>
</properties>
數據源配置
多數據源配置要求必須有一個是『主』,我們將RDS設定爲主,配置如下:
@Configuration
@MapperScan(basePackages = RdsDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "rdsSqlSessionFactory")
public class RdsDataSourceConfig {
static final String PACKAGE = "com.aliyun.xxx.repository.mybatis.rds";
@Value("${xxx_mysql_url}")
private String dbUrl;
@Value("${xxx_mysql_username}")
private String dbUser;
@Value("${xxx_mysql_password}")
private String dbPassword;
@Bean(name = "rdsDataSource")
@Primary
public DataSource rdsDataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl(dbUrl);
dataSource.setUsername(dbUser);
dataSource.setPassword(dbPassword);
return dataSource;
}
@Bean(name = "rdsTransactionManager")
@Primary
public DataSourceTransactionManager rdsTransactionManager() {
return new DataSourceTransactionManager(rdsDataSource());
}
@Bean(name = "rdsSqlSessionFactory")
@Primary
public SqlSessionFactory rdsSqlSessionFactory(@Qualifier("rdsDataSource") DataSource rdsDataSource) throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
sessionFactory.setDataSource(rdsDataSource);
return sessionFactory.getObject();
}
}
@Value
將獲取Spring Boot全局配置文件的kv配置。也可以通過Environment
對象的getProperty
方法獲得kv配置。@MapperScan
配置要掃描並容器管理的包路徑,這裏我們精確到rds,以便使其內的Mapper
(見下文)與其他數據源隔離。sqlSessionFactoryRef
要定義key唯一的SqlSessionFactory
實例,否則同名的處理是後者被忽略。
類似地,另一個數據源ADS的配置如下:
@Configuration
@MapperScan(basePackages = AdsDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "adsSqlSessionFactory")
public class AdsDataSourceConfig {
static final String PACKAGE = "com.aliyun.xxx.repository.mybatis.ads";
@Value("${xxx_ads_url}")
private String dbUrl;
@Value("${xxx_ads_username}")
private String dbUser;
@Value("${xxx_ads_password}")
private String dbPassword;
@Bean(name = "adsDataSource")
public DataSource adsDataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl(dbUrl);
dataSource.setUsername(dbUser);
dataSource.setPassword(dbPassword);
return dataSource;
}
@Bean(name = "adsTransactionManager")
public DataSourceTransactionManager adsTransactionManager(@Qualifier("adsDataSource") DataSource adsDataSource) {
return new DataSourceTransactionManager(adsDataSource);
}
@Bean(name = "adsSqlSessionFactory")
public SqlSessionFactory adsSqlSessionFactory(@Qualifier("adsDataSource") DataSource adsDataSource) throws Exception {
final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
sessionFactory.setDataSource(adsDataSource);
return sessionFactory.getObject();
}
}
Mapper
Mapper是mybatis的DAL層接口,其實現是由mybatis內部完成的,也就是說,我們只需要定義好接口即可完成CRUD。
com.aliyun.xxx.repository.mybatis.rds
包內的Mapper
只會用到RDS數據源。
package com.aliyun.xxx.repository.mybatis.rds;
@Mapper
public interface MetaMapper {
@SelectProvider(type = MetaSelectProvider.class, method = "xxxQueryById")
@Results(value ={
@Result(id=true, property="id",column="id",javaType=Long.class,jdbcType=JdbcType.BIGINT),
...
@Result(property="gmtCreate",column="gmt_create",javaType=Date.class,jdbcType=JdbcType.TIMESTAMP)})
List<XxxPojo> xxxQueryById(@Param("xxxId") String xxxId);
}
上述Mapper
定義了一個Select
方法,@SelectProvider
用於定義具體的SQL語句,@Results
用於定義具體的表字段與POJO屬性的映射。
MetaSelectProvider
可以使用MyBatis的API完成SQL的拼裝。
public class MetaSelectProvider {
private static final String xxxSQL = "id, ...,gmt_create";
public String xxxQueryById(Map<String, Object> parameter) {
org.apache.ibatis.jdbc.SQL sql = new org.apache.ibatis.jdbc.SQL();
sql.SELECT(xxxSQL).FROM("table_name").WHERE("biz_id=#{xxxId}");
return sql.toString();
}
}
DAO
@Repository
public class XxxDAO {
@Autowired
private MetaMapper metaMapper;
public List<XxxPojo> xxxQueryById(String xxxId) throws DataAccessException {
return metaMapper.xxxQueryById(xxxId);
}
}
SpringBootApplication
Spring Boot的入口類定義如下:
@SpringBootApplication
@PropertySource("file:/opt/xxx/xxx.properties")
public class XxxApplication {
public static void main(String[] args) {
SpringApplication.run(XxxApplication.class, args);
}
}
測試類
使用Spring的上下文,完成單元測試:
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = XxxApplication.class)
public class TestXxxDAO {
private static final Logger logger = LogManager.getLogger(RelevanceResource.class);
@Autowired
private XxxDAO dao;
@Test
public void testXxxById() {
String xxxId = "C00018";
List<XxxPojo> list = dao.xxxQueryById(xxxId);
Assert.assertNotNull(list);
logger.info(...);
}
}