JPARepository保存了一个大集合

Question

我正在创建一些应该将大量实体（大约8000及以上）保存到数据库的方法。目前DBMS是Postgres，但我预计将来我也必须与其他DBMS合作。

现在我尝试使用Spring，Hibernate和JPA，特别是JPARepository的方法。

到目前为止一切正常，单个CRUD操作工作正常，但是当我必须保存一个对象列表（正如我从一些测试中看到的那样）大于2000-3000个对象时，我开始遇到问题。

最初，为了保存我的实例，我正在这样做：

List<Entity> objectsToSave = someService.retrieveObjects();
for (Entity e: objectsToSave)
    svc.saveAndFlush(e);

但是，过了一会儿，给了我一个CannotCreateTransactionException，所以我认为这可能不是最好的选择，并尝试使用JPARepository提供的save(List<Entity>)方法，但是根本没有保存任何东西，我甚至在方法调用后尝试flush()但没有发生任何事情。

那么，这是最好和最正确的方法吗？我是否必须在配置中设置一些内容？

参见下面的Hibernate配置和堆栈跟踪。关于配置，我试图告诉Hibernate在每次事务之后关闭连接但是没有按预期工作，因为在第一次事务之后没有打开其他事务并且整个应用程序完全停止工作...

Hibernate配置：

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${database.driver}" />
    <property name="url" value="${database.url}" />
    <property name="username" value="${database.username}" />
    <property name="password" value="${database.password}" />
</bean>

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan" value="it.datapiano.portaleservizi.dto"/>
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
    </property>
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
            <prop key="hibernate.max_fetch_depth">3</prop>
            <prop key="hibernate.jdbc.fetch_size">50</prop>
            <prop key="hibernate.jdbc.batch_size">20</prop>
            <prop key="hibernate.show_sql">false</prop>
        </props>
    </property>
</bean>

堆栈跟踪：

org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:430)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:420)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:257)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.LockModeRepositoryPostProcessor$LockModePopulatingMethodIntercceptor.invoke(LockModeRepositoryPostProcessor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy44.saveAndFlush(Unknown Source)
    at it.xyz.foo.services.impl.BaseServiceImpl.saveAndFlush(BaseServiceImpl.java:59)
    at it.xyz.foo.services.impl.BaseServiceImpl.saveAndFlush(BaseServiceImpl.java:1)
    at sun.reflect.GeneratedMethodAccessor83.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:201)
    at com.sun.proxy.$Proxy47.saveAndFlush(Unknown Source)
    at it.xyz.foo.thread.ComuniThread.update(ComuniThread.java:54)
    at it.xyz.foo.thread.ComuniThread.run(ComuniThread.java:34)
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1387)
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1310)
    at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:1397)
    at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:62)
    at org.springframework.orm.jpa.DefaultJpaDialect.beginTransaction(DefaultJpaDialect.java:67)
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:110)
    at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380)
    ... 23 more
Caused by: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:132)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:221)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:157)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1426)
    at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:59)
    ... 26 more
Caused by: org.postgresql.util.PSQLException: Il tentativo di connessione è fallito.
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:225)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:64)
    at org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:138)
    at org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:29)
    at org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnection.java:21)
    at org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.java:31)
    at org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)
    at org.postgresql.Driver.makeConnection(Driver.java:410)
    at org.postgresql.Driver.connect(Driver.java:280)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:155)
    at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:120)
    at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:70)
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:292)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:214)
    ... 31 more
Caused by: java.net.BindException: Address already in use: connect
    at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at org.postgresql.core.PGStream.<init>(PGStream.java:60)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:101)
    ... 48 more

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