Question

两个用户同时使用我的简单应用程序，我得到例外：

Error Code: 0
Call: SELECT ID, NAME, IMAGE FROM GameObjectTable ORDER BY ID ASC
Query: ReadAllQuery(referenceClass=GameObject sql="SELECT ID, NAME, IMAGE FROM GameObjectTable ORDER BY ID ASC")

Caused by: org.postgresql.util.PSQLException: There was In/Out error while sending to server
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:283)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:479)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:367)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:271)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeSelect(DatabaseAccessor.java:891)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:601)
... 116 more
Caused by: java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:26)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:121)
at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:212)
at org.postgresql.core.PGStream.flush(PGStream.java:507)
at org.postgresql.core.v3.QueryExecutorImpl.sendSync(QueryExecutorImpl.java:1107)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:256)
... 121 more

方法cousing错误是：

@Repository
public class GameObjectDao{
  @PersistenceContext(type = PersistenceContextType.EXTENDED)
  protected EntityManager entityManager;
  @Transactional
  public List<String> getGameObjectNames() {
    return getEntityManager().createQuery("select g.name from GameObject as g").getResultList();
 ...
}

}

Spring事务管理器：

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
    <property name="dataSource" ref="dataSource"/>
</bean>
<tx:annotation-driven />

有什么问题？

// EDIT

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
            <property name="showSql" value="false"/>
        </bean>
    </property>

    <property name="loadTimeWeaver">
        <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>
    </property>
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect "/>
    </property>

</bean>

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

在mysql中错误不同：

 Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.apache.wicket.session.DefaultPageFactory.createPage(DefaultPageFactory.java:192)
... 69 more
    Caused by: java.lang.NullPointerException
at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:1646)
at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:1622)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1332)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeSelect(DatabaseAccessor.java:891)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:601)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:529)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeCall(AbstractSession.java:914)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:205)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:191)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelectCall(DatasourceCallQueryMechanism.java:262)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.selectAllRows(DatasourceCallQueryMechanism.java:618)
at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRowsFromTable(ExpressionQueryMechanism.java:2537)
at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRows(ExpressionQueryMechanism.java:2496)
at org.eclipse.persistence.queries.ReadAllQuery.executeObjectLevelReadQuery(ReadAllQuery.java:455)
at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeDatabaseQuery(ObjectLevelReadQuery.java:997)
at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:675)
at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:958)
at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:432)
at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1021)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2863)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1225)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1207)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1181)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.executeReadQuery(EJBQueryImpl.java:453)
at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getResultList(EJBQueryImpl.java:669)

Answer 1

如果第一个异常转换为（正如我猜的那样）：

org.postgresql.util.PSQLException: An I/O error occured while sending to the backend.

然后很可能不是EclipseLink问题而是PostgreSQL问题。

在服务器上的postgresql.conf中设置以下内容并重新加载：

log_statement=all
log_min_error_statement=ERROR
log_min_messages=ERROR
log_connections=on
log_disconnections=on

然后检查服务器日志并使用任何可疑消息（及其周围的行）更新您的问题。

Answer 2

第一个请求似乎正在关闭数据库连接，第二个请求从池中检索已关闭的连接并失败。

您的数据源定义是什么样的？

Eclipse链接jpa问题

2 个答案: