优雅地处理EJB / JPA环境中的约束违规？

时间：2010-03-25 22:30:29

标签： java database jpa java-ee ejb-3.0

我在Glassfish v3应用服务器上使用EJB和JPA。我有一个Entity类，我强制其中一个字段在@Column注释中是唯一的。

@Entity
public class MyEntity implements Serializable {

    private String uniqueName;

    public MyEntity() {
    }

    @Column(unique = true, nullable = false)
    public String getUniqueName() {
        return uniqueName;
    }

    public void setUniqueName(String uniqueName) {
        this.uniqueName = uniqueName;
    }
}

当我尝试将此字段设置为非唯一值的对象持久化时，当EJB容器管理的事务提交时，我得到异常（如预期的那样）。

我有两个问题需要解决：

1）我得到的异常是无用的“javax.ejb.EJBException：Transaction aborted”。如果我递归调用getCause（）足够多次，我最终会得到更有用的“java.sql.SQLIntegrityConstraintViolationException”，但是这个异常是EclipseLink实现的一部分，我真的不习惯依赖它的存在。

有没有更好的方法来获取JPA的详细错误信息？

2）EJB容器坚持记录此错误，即使我抓住它并处理它。

有没有更好的方法来处理此错误，这会阻止Glassfish使用无用的异常信息来混乱我的日志？

感谢。

2 个答案:

答案 0 :(得分：22)

  

我得到的异常是无用的“javax.ejb.EJBException：Transaction aborted”。 （...）

我在我身边做了一个测试（用GFv3和EclipseLink），我确认了这个行为。完整的堆栈跟踪是：

javax.ejb.EJBException: Transaction aborted
    at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:4997)
    at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4756)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1955)
    at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1906)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:198)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:84)
    at $Proxy218.myBusinessMethod(Unknown Source)
    at com.stackoverflow.q2522643.__EJB31_Generated__MyEJB__Intf____Bean__.myBusinessMethod(Unknown Source)
    at com.stackoverflow.q2522643.MyServlet.doGet(MyServlet.java:28)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
    at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:233)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
    at java.lang.Thread.run(Thread.java:619)
Caused by: javax.transaction.RollbackException: Transaction marked for rollback.
    at com.sun.enterprise.transaction.JavaEETransactionImpl.commit(JavaEETransactionImpl.java:450)
    at com.sun.enterprise.transaction.JavaEETransactionManagerSimplified.commit(JavaEETransactionManagerSimplified.java:837)
    at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:4991)
    ... 34 more
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'SQL100326111558470' defined on 'MYENTITY'.
Error Code: -1
Call: INSERT INTO MYENTITY (ID, NAME) VALUES (?, ?)
    bind => [2, Duke!]
Query: InsertObjectQuery(com.stackoverflow.q2522643.MyEntity@dba6a9)
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:324)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:800)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:866)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:586)
    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.insertObject(DatasourceCallQueryMechanism.java:334)
    at org.eclipse.persistence.internal.queries.StatementQueryMechanism.insertObject(StatementQueryMechanism.java:162)
    at org.eclipse.persistence.internal.queries.StatementQueryMechanism.insertObject(StatementQueryMechanism.java:177)
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.insertObjectForWrite(DatabaseQueryMechanism.java:461)
    at org.eclipse.persistence.queries.InsertObjectQuery.executeCommit(InsertObjectQuery.java:80)
    at org.eclipse.persistence.queries.InsertObjectQuery.executeCommitWithChangeSet(InsertObjectQuery.java:90)
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWriteWithChangeSet(DatabaseQueryMechanism.java:286)
    at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:58)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:675)
    at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:589)
    at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:109)
    at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:86)
    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:1167)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitNewObjectsForClassWithChangeSet(CommitManager.java:197)
    at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:103)
    at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:3260)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1405)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.commitToDatabase(RepeatableWriteUnitOfWork.java:547)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1510)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.issueSQLbeforeCompletion(UnitOfWorkImpl.java:3134)
    at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.issueSQLbeforeCompletion(RepeatableWriteUnitOfWork.java:268)
    at org.eclipse.persistence.transaction.AbstractSynchronizationListener.beforeCompletion(AbstractSynchronizationListener.java:157)
    at org.eclipse.persistence.transaction.JTASynchronizationListener.beforeCompletion(JTASynchronizationListener.java:68)
    at com.sun.enterprise.transaction.JavaEETransactionImpl.commit(JavaEETransactionImpl.java:412)
    ... 36 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'SQL100326111558470' defined on 'MYENTITY'.
    at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
    at com.sun.gjc.spi.base.PreparedStatementWrapper.executeUpdate(PreparedStatementWrapper.java:108)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:791)
    ... 69 more
Caused by: org.apache.derby.client.am.SqlException: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'SQL100326111558470' defined on 'MYENTITY'.
    at org.apache.derby.client.am.Statement.completeExecute(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source)
    at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source)
    at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.readExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
    at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
    ... 72 more

正如我们所看到的，EclipseLink实际上抛出了一个o.e.p.e.DatabaseException，然后被容器捕获。但这是错误。 EclipseLink应该抛出一个PersistenceException（来自JPA），或者抛出一个子类，但肯定不是特定于提供者的异常。这 是一个错误，你应该这样报告：https://glassfish.dev.java.net/servlets/ProjectIssues（在 entity-persistence 子组件中）。

你是绝对正确的，为了便携性，你应该不捕获提供者特定的例外。您应该捕获JPA PersistenceException或子类（然后查看包装的SQLException）。由于EclipseLink错误，您可能必须（暂时）在这种特殊情况下，但这是一种解决方法。

答案 1 :(得分：5)

我不知道如何以可移植的方式检测唯一约束违规，我提出的最好的只是处理PersistenceException。如果有人能回答我也会感兴趣的话。

我可以帮助解决日志问题。

在persistence.xml中的持久性单元内添加以下内容：

<properties>
  <property name="eclipselink.logging.level" value="SEVERE"/>
</properties>

这将摆脱一些例外。您仍将看到容器在CMT提交时看到异常的堆栈跟踪。你必须在容器看到它们之前吞下它们。您可以执行以下操作。

1）创建特定于应用程序的异常以指示持久性问题。我调用了我的DataStoreException。

2）不要使用无界面视图bean。将DataStoreException添加到biz界面中方法签名的throws子句中。

3）将以下方法添加到EJB中：

@AroundInvoke
public Object interceptor(InvocationContext ic) throws Exception {
    Object o = null;
    try {
        o = ic.proceed();
        if (!sessionContext.getRollbackOnly()) {
            entityManager.flush();
        }
    } catch (PersistenceException ex) {
        throw new DataStoreException(ex);
    }
    return o;
}
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