java IO异常:流已关闭
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java IO Exception: Stream Closed
提问by ez4nick
This is the code I currently have:
这是我目前拥有的代码:
public class FileStatus extends Status{
FileWriter writer;
public FileStatus(){
try {
writer = new FileWriter("status.txt",true);
} catch (IOException e) {
e.printStackTrace();
}
}
public void writeToFile(){
String file_text= pedStatusText + " " + gatesStatus + " " + DrawBridgeStatusText;
try {
writer.write(file_text);
writer.flush();
writer.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Everything works as expected (The file is written to when the writeToFile method is called). However when the writeToFile method is called a second time I get the following error:
一切都按预期工作(调用 writeToFile 方法时写入文件)。但是,当第二次调用 writeToFile 方法时,我收到以下错误:
java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:45)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:118)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:135)
at java.io.OutputStreamWriter.write(OutputStreamWriter.java:220)
at java.io.Writer.write(Writer.java:157)
at FileStatus.writeToFile(FileStatus.java:19)
at MenuBar.actionPerformed(MenuBar.java:115)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:703)
at java.awt.EventQueue.accesspublic void writeToFile(){
String file_text= pedStatusText + " " + gatesStatus + " " + DrawBridgeStatusText;
try {
writer.write(file_text);
writer.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
0(EventQueue.java:102)
at java.awt.EventQueue.run(EventQueue.java:662)
at java.awt.EventQueue.run(EventQueue.java:660)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue.run(EventQueue.java:676)
at java.awt.EventQueue.run(EventQueue.java:674)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:673)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:45)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:118)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:135)
at java.io.OutputStreamWriter.write(OutputStreamWriter.java:220)
at java.io.Writer.write(Writer.java:157)
at FileStatus.writeToFile(FileStatus.java:19)
at MenuBar.actionPerformed(MenuBar.java:115)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:703)
at java.awt.EventQueue.accesspublic void cleanUp() {
writer.close();
}
0(EventQueue.java:102)
at java.awt.EventQueue.run(EventQueue.java:662)
at java.awt.EventQueue.run(EventQueue.java:660)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue.run(EventQueue.java:676)
at java.awt.EventQueue.run(EventQueue.java:674)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:673)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:45)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:118)
at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:135)
at java.io.OutputStreamWriter.write(OutputStreamWriter.java:220)
at java.io.Writer.write(Writer.java:157)
at FileStatus.writeToFile(FileStatus.java:19)
at MenuBar.actionPerformed(MenuBar.java:115)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
the file is still written to the second time as expected but it throws this error on the second and future calls to writeToFile(). I am wondering what is causing this error to happen.
该文件仍按预期第二次写入,但它会在第二次和以后的 writeToFile() 调用中引发此错误。我想知道是什么导致了这个错误发生。
采纳答案by christopher
You're calling writer.close();
after you've done writing to it. Once a stream is closed, it can not be written to again. Usually, the way I go about implementing this is by moving the close out of the write to method.
你writer.close();
写完后打电话给它。流一旦关闭,就不能再写入。通常,我实现这一点的方法是将 close 移出 write to 方法。
public void writeToFile() {
FileWriter writer = new FileWriter("status.txt", true);
// ... Write to the file.
writer.close();
}
And add a method cleanUp
to close the stream.
并添加cleanUp
关闭流的方法。
This means that you have the responsibility to make sure that you're calling cleanUp
when you're done writing to the file. Failure to do this will result in memory leaks and resource locking.
这意味着您有责任确保cleanUp
在完成写入文件后正在调用。不这样做将导致内存泄漏和资源锁定。
EDIT: You can create a new stream each time you want to write to the file, by moving writer
into the writeToFile()
method..
编辑:您可以在每次要写入文件时创建一个新流,方法是移动writer
到writeToFile()
方法中。
回答by cybersam
Don't call write.close()
in writeToFile()
.
不要叫write.close()
在writeToFile()
。
回答by NSF
You call writer.close();
in writeToFile
so the writer has been closed the second time you call writeToFile
.
您调用writer.close();
,writeToFile
因此作者已在您第二次调用时关闭writeToFile
。
Why don't you merge FileStatus
into writeToFile
?
你为什么不合并FileStatus
成writeToFile
?