在实际开发中，我们会遇到一个应用需要访问多个数据源的情况。因此，我们需要配置多个数据源。这里我们来看看使用 Jpa 实现多数据源配置。
添加 JPA 依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
配置数据源信息
- application.properties
# 数据源一
spring.datasource.primary.jdbc-url=jdbc:mysql://localhost:3306/product?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
spring.datasource.primary.diver-class-name=com.mysql.jdbc.Driver
spring.datasource.primary.username=root
spring.datasource.primary.password=root
# 数据源二
spring.datasource.secondary.jdbc-url=jdbc:mysql://localhost:3306/game?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
spring.datasource.secondary.diver-class-name=com.mysql.jdbc.Driver
spring.datasource.secondary.username=root
spring.datasource.secondary.password=root
# JPA 配置
spring.jpa.database=mysql
spring.jpa.generate-ddl=true
spring.jpa.show-sql=true
spring.jpa.open-in-view=false
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
spring.jpa.hibernate.naming.implicit-strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
配置多数据源
集成 JPA 配置数据源步骤如下：
- 创建数据源
DataSource - 创建实体管理器工厂对象
LocalContainerEntityManagerFactoryBean - 创建实体管理器对象
EntityManager - 创建事务管理器对象
PlatformTransactionManager
数据源一
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactoryPrimary",
transactionManagerRef = "transactionManagerPrimary",
basePackages = {"com.example.jpa.repository.primary"})
public class PrimaryDataSourceConfig {
@Autowired
private JpaProperties jpaProperties;
@Autowired
private HibernateProperties hibernateProperties;
@Bean(name = "primaryDataSource")
@Primary
@ConfigurationProperties(prefix = "spring.datasource.primary")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}
private Map<String, Object> getVendorProperties() {
return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
}
@Bean(name = "entityManagerFactoryPrimary")
@Primary
public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) {
return builder.dataSource(dataSource())
.properties(getVendorProperties())
// 设置映射的实体类位置
.packages("com.example.jpa.entity.primary")
.persistenceUnit("primaryPersistenceUnit")
.build();
}
@Bean(name = "entityManagerPrimary")
@Primary
public EntityManager entityManager(EntityManagerFactoryBuilder builder){
return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
}
@Bean(name = "transactionManagerPrimary")
@Primary
public PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
}
}
数据源二
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactorySecondary",
transactionManagerRef = "transactionManagerSecondary",
basePackages = {"com.example.jpa.repository.secondary"})
public class SecondaryDataSourceConfig {
@Autowired
private JpaProperties jpaProperties;
@Autowired
private HibernateProperties hibernateProperties;
@Bean(name = "secondaryDatasource")
@ConfigurationProperties(prefix = "spring.datasource.secondary")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}
private Map<String, Object> getVendorProperties() {
return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
}
@Bean(name = "entityManagerFactorySecondary")
public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {
return builder.dataSource(dataSource())
.properties(getVendorProperties())
// 设置映射的实体类位置
.packages("com.example.jpa.entity.secondary")
.persistenceUnit("secondaryPersistenceUnit")
.build();
}
@Bean(name = "entityManagerSecondary")
public EntityManager entityManagerSecondary(EntityManagerFactoryBuilder builder) {
return entityManagerFactorySecondary(builder).getObject().createEntityManager();
}
@Bean(name = "transactionManagerSecondary")
public PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
}
}
以上完成之后，多数据源配置就已经完成了，接下来就可以操作数据啦！
最后， 详细代码可以查看本示例的 Demo。