在单数据源的情况下,Spring Boot的配置非常简单,只需要在application.properties
文件中配置连接参数即可。但是往往随着业务量发展,我们通常会进行数据库拆分或是引入其他数据库,从而我们需要配置多个数据源,下面基于之前的JdbcTemplate和Spring-data-jpa例子分别介绍两种多数据源的配置方式。
多数据源配置
创建一个Spring配置类,定义两个DataSource
@Configuration public class DataSourceConfig { @Bean(name = "primaryDataSource") @Qualifier("primaryDataSource") @ConfigurationProperties(prefix="spring.datasource.primary") public DataSource primaryDataSource() { return DataSourceBuilder.create().build(); } @Bean(name = "secondaryDataSource") @Qualifier("secondaryDataSource") @Primary @ConfigurationProperties(prefix="spring.datasource.secondary") public DataSource secondaryDataSource() { return DataSourceBuilder.create().build(); } }
对应的application.properties
配置如下:
spring.datasource.primary.url=jdbc:mysql://localhost:3306/test1 spring.datasource.primary.username=root spring.datasource.primary.password=root spring.datasource.primary.driver-class-name=com.mysql.jdbc.Driver spring.datasource.secondary.url=jdbc:mysql://localhost:3306/test2 spring.datasource.secondary.username=root spring.datasource.secondary.password=root spring.datasource.secondary.driver-class-name=com.mysql.jdbc.Driver
JdbcTemplate支持
对JdbcTemplate的支持比较简单,只需要为其注入对应的datasource即可,如下例子,在创建JdbcTemplate的时候分别注入名为primaryDataSource
和secondaryDataSource
的数据源来区分不同的JdbcTemplate。
@Bean(name = "primaryJdbcTemplate") public JdbcTemplate primaryJdbcTemplate( @Qualifier("primaryDataSource") DataSource dataSource) { return new JdbcTemplate(dataSource); } @Bean(name = "secondaryJdbcTemplate") public JdbcTemplate secondaryJdbcTemplate( @Qualifier("secondaryDataSource") DataSource dataSource) { return new JdbcTemplate(dataSource); }
接下来通过测试用例来演示如何使用这两个针对不同数据源的JdbcTemplate。
@RunWith(SpringJUnit4ClassRunner.class) @SpringApplicationConfiguration(Application.class) public class ApplicationTests { @Autowired @Qualifier("primaryJdbcTemplate") protected JdbcTemplate jdbcTemplate1; @Autowired @Qualifier("secondaryJdbcTemplate") protected JdbcTemplate jdbcTemplate2; @Before public void setUp() { jdbcTemplate1.update("DELETE FROM USER "); jdbcTemplate2.update("DELETE FROM USER "); } @Test public void test() throws Exception { // 往第一个数据源中插入两条数据 jdbcTemplate1.update("insert into user(id,name,age) values(?, ?, ?)", 1, "aaa", 20); jdbcTemplate1.update("insert into user(id,name,age) values(?, ?, ?)", 2, "bbb", 30); // 往第二个数据源中插入一条数据,若插入的是第一个数据源,则会主键冲突报错 jdbcTemplate2.update("insert into user(id,name,age) values(?, ?, ?)", 1, "aaa", 20); // 查一下第一个数据源中是否有两条数据,验证插入是否成功 Assert.assertEquals("2", jdbcTemplate1.queryForObject("select count(1) from user", String.class)); // 查一下第一个数据源中是否有两条数据,验证插入是否成功 Assert.assertEquals("1", jdbcTemplate2.queryForObject("select count(1) from user", String.class)); } }
Spring-data-jpa支持
新增对第一数据源的JPA配置,注意两处注释的地方,用于指定数据源对应的Entity
实体和Repository
定义位置,用@Primary
区分主数据源。
@Configuration @EnableTransactionManagement @EnableJpaRepositories( entityManagerFactoryRef="entityManagerFactoryPrimary", transactionManagerRef="transactionManagerPrimary", basePackages= { "com.didispace.domain.p" }) //设置Repository所在位置 public class PrimaryConfig { @Autowired @Qualifier("primaryDataSource") private DataSource primaryDataSource; @Primary @Bean(name = "entityManagerPrimary") public EntityManager entityManager(EntityManagerFactoryBuilder builder) { return entityManagerFactoryPrimary(builder).getObject().createEntityManager(); } @Primary @Bean(name = "entityManagerFactoryPrimary") public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary (EntityManagerFactoryBuilder builder) { return builder .dataSource(primaryDataSource) .properties(getVendorProperties(primaryDataSource)) .packages("com.didispace.domain.p") //设置实体类所在位置 .persistenceUnit("primaryPersistenceUnit") .build(); } @Autowired private JpaProperties jpaProperties; private Map<String, String> getVendorProperties(DataSource dataSource) { return jpaProperties.getHibernateProperties(dataSource); } @Primary @Bean(name = "transactionManagerPrimary") public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) { return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject()); } }
新增对第二数据源的JPA配置,内容与第一数据源类似,具体如下:
@Configuration @EnableTransactionManagement @EnableJpaRepositories( entityManagerFactoryRef="entityManagerFactorySecondary", transactionManagerRef="transactionManagerSecondary", basePackages= { "com.didispace.domain.s" }) //设置Repository所在位置 public class SecondaryConfig { @Autowired @Qualifier("secondaryDataSource") private DataSource secondaryDataSource; @Bean(name = "entityManagerSecondary") public EntityManager entityManager(EntityManagerFactoryBuilder builder) { return entityManagerFactorySecondary(builder).getObject().createEntityManager(); } @Bean(name = "entityManagerFactorySecondary") public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary (EntityManagerFactoryBuilder builder) { return builder .dataSource(secondaryDataSource) .properties(getVendorProperties(secondaryDataSource)) .packages("com.didispace.domain.s") //设置实体类所在位置 .persistenceUnit("secondaryPersistenceUnit") .build(); } @Autowired private JpaProperties jpaProperties; private Map<String, String> getVendorProperties(DataSource dataSource) { return jpaProperties.getHibernateProperties(dataSource); } @Bean(name = "transactionManagerSecondary") PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) { return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject()); } }
完成了以上配置之后,主数据源的实体和数据访问对象位于:com.didispace.domain.p
,次数据源的实体和数据访问接口位于:com.didispace.domain.s
。