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關于IO的問題，為什么結束了將持久化對象保存到數據庫最后關掉了inputstream會導致錯誤。

public?void?testSavePicture()?{
		SimpleDateFormat?sdf?=?new?SimpleDateFormat("yyyy-MM-dd");
		Date?date;
		try?{
			date?=?sdf.parse("1987-04-01");
			Student?s?=?new?Student(0,?"kula",?date);
			File?file?=?new?File("/Users/kk/Desktop/photo/3.pic.jpg");			
			InputStream?in?=?new?FileInputStream(file);
			Blob?image?=?Hibernate.getLobCreator(session).createBlob(in,?in.available());
			s.setPicture(image);
			session.save(s);
			
			//in.close();?如果關掉輸入流會報錯。
		}?catch?(ParseException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}?catch?(FileNotFoundException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}?catch?(IOException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}

	}

如果關閉了輸入流執行不成功會報以下錯誤。

avax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not execute statement

? ? at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:147)

? ? at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:155)

? ? at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:162)

? ? at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1402)

? ? at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:472)

? ? at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3132)

? ? at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2369)

? ? at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:467)

? ? at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:147)

? ? at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38)

? ? at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:221)

? ? at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)

? ? at junit.StudentTest.destroy(StudentTest.java:120)

? ? at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

? ? at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

? ? at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

? ? at java.lang.reflect.Method.invoke(Method.java:498)

? ? at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)

? ? at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

? ? at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)

? ? at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:33)

? ? at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)

? ? at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)

? ? at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)

? ? at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)

? ? at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)

? ? at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)

? ? at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)

? ? at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)

? ? at org.junit.runners.ParentRunner.run(ParentRunner.java:309)

? ? at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)

? ? at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

? ? at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)

? ? at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)

? ? at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)

? ? at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Caused by: org.hibernate.exception.GenericJDBCException: could not execute statement

? ? at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)

? ? at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)

? ? at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)

? ? at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:207)

? ? at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:45)

? ? at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2934)

? ? at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3434)

? ? at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:89)

? ? at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:560)

? ? at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:434)

? ? at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:337)

? ? at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)

? ? at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1396)

? ? ... 32 more

Caused by: java.sql.SQLException: Error reading from InputStream java.io.IOException

? ? at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)

? ? at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896)

? ? at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885)

? ? at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)

? ? at com.mysql.jdbc.PreparedStatement.readblock(PreparedStatement.java:2664)

? ? at com.mysql.jdbc.PreparedStatement.streamToBytes(PreparedStatement.java:4456)

? ? at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:2190)

? ? at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2052)

? ? at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2009)

? ? at com.mysql.jdbc.PreparedStatement.executeLargeUpdate(PreparedStatement.java:5094)

? ? at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1994)

? ? at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:204)

? ? ... 41 more

Caused by: java.io.IOException: Stream Closed

? ? at java.io.FileInputStream.readBytes(Native Method)

? ? at java.io.FileInputStream.read(FileInputStream.java:255)

? ? at com.mysql.jdbc.PreparedStatement.readblock(PreparedStatement.java:2662)

? ? ... 48 more

可是io不是應該在用完后就關掉嗎。

萌萌噠貓頭鷹

2016-07-03

源自：Hibernate初探之單表映射 3-5

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2 回答

萌萌噠貓頭鷹提問者
2016-07-04

這個沒法解釋取出照片關閉了io，能正常通過。

public?void?testGetPicture()?{
		Student?s?=?(Student)?session.get(Student.class,?1);
		Blob?image?=?s.getPicture();
		try?{
			FileOutputStream?out?=?new?FileOutputStream("image/c1py.jpg");
			InputStream?in?=?image.getBinaryStream();
			byte[]?barray?=?new?byte[1024];
			int?bytes;
			while?((bytes?=?in.read(barray,?0,?barray.length))?>?0)?{
				out.write(barray,?0,?bytes);
			}
			out.close();
			in.close();
		}?catch?(FileNotFoundException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}?catch?(SQLException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}?catch?(IOException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}
	}

以上代碼可以執行。

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最終也沒有

正如一樓的朋友說的。 session.save后，還要運行transaction.commit(); // 提交事務，才能把數據寫入數據庫中你試試把：transaction.commit(); 寫在session.save的下一行然后再在下一行寫入in.close();就不會報錯了。而你展示的代碼，是讀取的時候的操作。沒有寫入操作，所以不需要向數據庫提交事務。不提交事務，所以沒有用到transaction.commit();這個代碼所以可以直接使用in.close()