如何配置和使用两个数据源?
例如,这是我的第一个数据源:
application.properties
#first db
spring.datasource.url = [url]
spring.datasource.username = [username]
spring.datasource.password = [password]
spring.datasource.driverClassName = oracle.jdbc.OracleDriver
#second db ...
应用程序类
@SpringBootApplication
public class SampleApplication
{
public static void main(String[] args) {
SpringApplication.run(SampleApplication.class, args);
}
}
如何修改应用。属性添加另一个数据源?我如何自动装配它以供不同的存储库使用?
给你。
添加到您的应用程序中。属性文件:
#first db
spring.datasource.url = [url]
spring.datasource.username = [username]
spring.datasource.password = [password]
spring.datasource.driverClassName = oracle.jdbc.OracleDriver
#second db ...
spring.secondDatasource.url = [url]
spring.secondDatasource.username = [username]
spring.secondDatasource.password = [password]
spring.secondDatasource.driverClassName = oracle.jdbc.OracleDriver
在任何带@Configuration注解的类中添加以下方法:
@Bean
@Primary
@ConfigurationProperties(prefix="spring.datasource")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
@Bean
@ConfigurationProperties(prefix="spring.secondDatasource")
public DataSource secondaryDataSource() {
return DataSourceBuilder.create().build();
}
如果两个数据源位于相同的db location/server上,@Primary注释用于下面的方法效果很好。
@Bean(name = "datasource1")
@ConfigurationProperties("database1.datasource")
@Primary
public DataSource dataSource(){
return DataSourceBuilder.create().build();
}
@Bean(name = "datasource2")
@ConfigurationProperties("database2.datasource")
public DataSource dataSource2(){
return DataSourceBuilder.create().build();
}
如果数据源在不同的服务器上,最好使用@Component和@Primary注释。下面的代码片段适用于位于不同位置的两个不同数据源
database1.datasource.url = jdbc:mysql://127.0.0.1:3306/db1
database1.datasource.username = root
database1.datasource.password = mysql
database1.datasource.driver-class-name=com.mysql.jdbc.Driver
database2.datasource1.url = jdbc:mysql://192.168.113.51:3306/db2
database2.datasource1.username = root
database2.datasource1.password = mysql
database2.datasource1.driver-class-name=com.mysql.jdbc.Driver
@Configuration
@Primary
@Component
@ComponentScan("com.db1.bean")
class DBConfiguration1{
@Bean("db1Ds")
@ConfigurationProperties(prefix="database1.datasource")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
}
@Configuration
@Component
@ComponentScan("com.db2.bean")
class DBConfiguration2{
@Bean("db2Ds")
@ConfigurationProperties(prefix="database2.datasource1")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
}
我用的是mybatis springboot 2.0技术栈,
解决方案:
//application.properties - start
sp.ds1.jdbc-url=jdbc:mysql://localhost:3306/mydb?useSSL=false
sp.ds1.username=user
sp.ds1.password=pwd
sp.ds1.testWhileIdle=true
sp.ds1.validationQuery=SELECT 1
sp.ds1.driverClassName=com.mysql.jdbc.Driver
sp.ds2.jdbc-url=jdbc:mysql://localhost:4586/mydb?useSSL=false
sp.ds2.username=user
sp.ds2.password=pwd
sp.ds2.testWhileIdle=true
sp.ds2.validationQuery=SELECT 1
sp.ds2.driverClassName=com.mysql.jdbc.Driver
//application.properties - end
//configuration class
@Configuration
@ComponentScan(basePackages = "com.mypkg")
public class MultipleDBConfig {
public static final String SQL_SESSION_FACTORY_NAME_1 = "sqlSessionFactory1";
public static final String SQL_SESSION_FACTORY_NAME_2 = "sqlSessionFactory2";
public static final String MAPPERS_PACKAGE_NAME_1 = "com.mypg.mymapper1";
public static final String MAPPERS_PACKAGE_NAME_2 = "com.mypg.mymapper2";
@Bean(name = "mysqlDb1")
@Primary
@ConfigurationProperties(prefix = "sp.ds1")
public DataSource dataSource1() {
System.out.println("db1 datasource");
return DataSourceBuilder.create().build();
}
@Bean(name = "mysqlDb2")
@ConfigurationProperties(prefix = "sp.ds2")
public DataSource dataSource2() {
System.out.println("db2 datasource");
return DataSourceBuilder.create().build();
}
@Bean(name = SQL_SESSION_FACTORY_NAME_1)
@Primary
public SqlSessionFactory sqlSessionFactory1(@Qualifier("mysqlDb1") DataSource dataSource1) throws Exception {
System.out.println("sqlSessionFactory1");
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setTypeHandlersPackage(MAPPERS_PACKAGE_NAME_1);
sqlSessionFactoryBean.setDataSource(dataSource1);
SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBean.getObject();
sqlSessionFactory.getConfiguration().setMapUnderscoreToCamelCase(true);
sqlSessionFactory.getConfiguration().setJdbcTypeForNull(JdbcType.NULL);
return sqlSessionFactory;
}
@Bean(name = SQL_SESSION_FACTORY_NAME_2)
public SqlSessionFactory sqlSessionFactory2(@Qualifier("mysqlDb2") DataSource dataSource2) throws Exception {
System.out.println("sqlSessionFactory2");
SqlSessionFactoryBean diSqlSessionFactoryBean = new SqlSessionFactoryBean();
diSqlSessionFactoryBean.setTypeHandlersPackage(MAPPERS_PACKAGE_NAME_2);
diSqlSessionFactoryBean.setDataSource(dataSource2);
SqlSessionFactory sqlSessionFactory = diSqlSessionFactoryBean.getObject();
sqlSessionFactory.getConfiguration().setMapUnderscoreToCamelCase(true);
sqlSessionFactory.getConfiguration().setJdbcTypeForNull(JdbcType.NULL);
return sqlSessionFactory;
}
@Bean
@Primary
public MapperScannerConfigurer mapperScannerConfigurer1() {
System.out.println("mapperScannerConfigurer1");
MapperScannerConfigurer configurer = new MapperScannerConfigurer();
configurer.setBasePackage(MAPPERS_PACKAGE_NAME_1);
configurer.setSqlSessionFactoryBeanName(SQL_SESSION_FACTORY_NAME_1);
return configurer;
}
@Bean
public MapperScannerConfigurer mapperScannerConfigurer2() {
System.out.println("mapperScannerConfigurer2");
MapperScannerConfigurer configurer = new MapperScannerConfigurer();
configurer.setBasePackage(MAPPERS_PACKAGE_NAME_2);
configurer.setSqlSessionFactoryBeanName(SQL_SESSION_FACTORY_NAME_2);
return configurer;
}
}
注意:
1)@Primary -> @Primary
2)。属性中的“jdbc-url”-> Spring Boot 2.0迁移后:需要jdbcUrl和driverClassName
我的需求略有不同,但使用了两个数据源。
我为来自同一个包的同一个JPA实体使用了两个数据源。一个用于在服务器启动时执行DDL以创建/更新表,另一个用于运行时执行DML。
DDL连接应该在DDL语句执行之后关闭,以防止在代码的任何地方进一步使用超级用户特权。
属性
spring.datasource.url=jdbc:postgresql://Host:port
ddl.user=ddluser
ddl.password=ddlpassword
dml.user=dmluser
dml.password=dmlpassword
spring.datasource.driver-class-name=org.postgresql.Driver
数据源配置类
// DDL数据源的第一个配置类
public class DatabaseDDLConfig {
@Bean
public LocalContainerEntityManagerFactoryBean ddlEntityManagerFactoryBean() {
LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
PersistenceProvider persistenceProvider = new
org.hibernate.jpa.HibernatePersistenceProvider();
entityManagerFactoryBean.setDataSource(ddlDataSource());
entityManagerFactoryBean.setPackagesToScan(new String[] {
"com.test.two.data.sources"});
HibernateJpaVendorAdapter vendorAdapter = new
HibernateJpaVendorAdapter();
entityManagerFactoryBean.setJpaVendorAdapter(vendorAdapter);
HashMap<String, Object> properties = new HashMap<>();
properties.put("hibernate.dialect",
"org.hibernate.dialect.PostgreSQLDialect");
properties.put("hibernate.physical_naming_strategy",
"org.springframework.boot.orm.jpa.hibernate.
SpringPhysicalNamingStrategy");
properties.put("hibernate.implicit_naming_strategy",
"org.springframework.boot.orm.jpa.hibernate.
SpringImplicitNamingStrategy");
properties.put("hibernate.hbm2ddl.auto", "update");
entityManagerFactoryBean.setJpaPropertyMap(properties);
entityManagerFactoryBean.setPersistenceUnitName("ddl.config");
entityManagerFactoryBean.setPersistenceProvider(persistenceProvider);
return entityManagerFactoryBean;
}
@Bean
public DataSource ddlDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
dataSource.setUrl(env.getProperty("spring.datasource.url"));
dataSource.setUsername(env.getProperty("ddl.user");
dataSource.setPassword(env.getProperty("ddl.password"));
return dataSource;
}
@Bean
public PlatformTransactionManager ddlTransactionManager() {
JpaTransactionManager transactionManager = new JpaTransactionManager();
transactionManager.setEntityManagerFactory(ddlEntityManagerFactoryBean().getObject());
return transactionManager;
}
}
// DML数据源的第二个配置类
public class DatabaseDMLConfig {
@Bean
@Primary
public LocalContainerEntityManagerFactoryBean dmlEntityManagerFactoryBean() {
LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
PersistenceProvider persistenceProvider = new org.hibernate.jpa.HibernatePersistenceProvider();
entityManagerFactoryBean.setDataSource(dmlDataSource());
entityManagerFactoryBean.setPackagesToScan(new String[] { "com.test.two.data.sources" });
JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
entityManagerFactoryBean.setJpaVendorAdapter(vendorAdapter);
entityManagerFactoryBean.setJpaProperties(defineJpaProperties());
entityManagerFactoryBean.setPersistenceUnitName("dml.config");
entityManagerFactoryBean.setPersistenceProvider(persistenceProvider);
return entityManagerFactoryBean;
}
@Bean
@Primary
public DataSource dmlDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(env.getProperty("spring.datasource.driver-class-name"));
dataSource.setUrl(envt.getProperty("spring.datasource.url"));
dataSource.setUsername("dml.user");
dataSource.setPassword("dml.password");
return dataSource;
}
@Bean
@Primary
public PlatformTransactionManager dmlTransactionManager() {
JpaTransactionManager transactionManager = new JpaTransactionManager();
transactionManager.setEntityManagerFactory(dmlEntityManagerFactoryBean().getObject());
return transactionManager;
}
}
// DDL数据源在代码中的使用。
public class DDLServiceAtStartup {
//Import persistence unit ddl.config for ddl purpose.
@PersistenceUnit(unitName = "ddl.config")
private EntityManagerFactory entityManagerFactory;
public void executeDDLQueries() throws ContentServiceSystemError {
try {
EntityManager entityManager = entityManagerFactory.createEntityManager();
entityManager.getTransaction().begin();
entityManager.createNativeQuery("query to create/update table").executeUpdate();
entityManager.flush();
entityManager.getTransaction().commit();
entityManager.close();
//Close the ddl data source to avoid from further use in code.
entityManagerFactory.close();
} catch(Exception ex) {}
}
//在代码中使用DML数据源。
public class DDLServiceAtStartup {
@PersistenceUnit(unitName = "dml.config")
private EntityManagerFactory entityManagerFactory;
public void createRecord(User user) {
userDao.save(user);
}
}
在Spring Boot application.properties中声明一个数据源
spring.datasource.company.url=jdbc:mysql://localhost/company_db?createDatabaseIfNotExist=true&autoReconnect=true&useSSL=false&allowPublicKeyRetrieval=true
spring.datasource.company.username=root
spring.datasource.company.password=root
spring.datasource.company.platform=mysql
spring.datasource.employee.url=jdbc:mysql://localhost/employee_db?createDatabaseIfNotExist=true&autoReconnect=true&useSSL=false&allowPublicKeyRetrieval=true
spring.datasource.employee.username=root
spring.datasource.employee.password=root
spring.datasource.employee.platform=mysql
使用多个数据源时,我们需要声明多个bean
Spring应用程序上下文中的不同映射。
使用配置类
@Configuration
@EnableJpaRepositories(basePackages = "com.example.multiple.datasources.entity.company",
entityManagerFactoryRef = "companyEntityManagerFactory",
transactionManagerRef = "companyTransactionManager")
public class CompanyDataSourceConfiguration {
@Bean
@ConfigurationProperties("spring.datasource.company")
public DataSourceProperties companyDataSourceProperties() {
return new DataSourceProperties();
}
@Bean
@ConfigurationProperties("spring.datasource.company.configuration")
public DataSource companyDataSource() {
return companyDataSourceProperties().initializeDataSourceBuilder()
.type(HikariDataSource.class).build();
}
@Bean(name = "companyEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean companyEntityManagerFactory(EntityManagerFactoryBuilder builder) {
return builder.dataSource(companyDataSource()).packages(Company.class).build();
}
@Bean
public PlatformTransactionManager companyTransactionManager(
final @Qualifier("companyEntityManagerFactory") LocalContainerEntityManagerFactoryBean companyEntityManagerFactory
) {
return new JpaTransactionManager(companyEntityManagerFactory.getObject());
}
}
我们需要声明其中一个数据源为@Primary。这是因为
EntityManagerFactoryBuilder在jpbasaseconfiguration和中声明
该类需要注入单个数据源。
@Configuration
@EnableJpaRepositories(basePackages = "com.example.multiple.datasources.entity.employee",
entityManagerFactoryRef = "employeeEntityManagerFactory",
transactionManagerRef = "employeeTransactionManager")
public class EmployeeDatasourceConfiguration {
@Bean
@Primary
@ConfigurationProperties("spring.datasource.employee")
public DataSourceProperties employeeDataSourceProperties() {
return new DataSourceProperties();
}
@Bean
@Primary
@ConfigurationProperties("spring.datasource.employee.configuration")
public DataSource employeeDataSource() {
return employeeDataSourceProperties().initializeDataSourceBuilder().type(HikariDataSource.class).build();
}
@Primary
@Bean("employeeEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean employeeEntityManagerFactory(EntityManagerFactoryBuilder builder) {
return builder.dataSource(employeeDataSource()).packages(Employee.class).build();
}
@Primary
@Bean
public PlatformTransactionManager employeeTransactionManager(
final @Qualifier("employeeEntityManagerFactory") LocalContainerEntityManagerFactoryBean employeeEntityManagerFactory
) {
return new JpaTransactionManager(employeeEntityManagerFactory.getObject());
}
}