当前位置: 首页 > 面试题库 >

java IO异常:流关闭

解博明
2023-03-14
问题内容

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();
    }
}
}

一切都会按预期进行(调用writeToFile方法时将文件写入)。但是,当第二次调用writeToFile方法时,出现以下错误:

    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$9.actionPerformed(MenuBar.java:115)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$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.access$000(EventQueue.java:102)
    at java.awt.EventQueue$3.run(EventQueue.java:662)
    at java.awt.EventQueue$3.run(EventQueue.java:660)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:676)
    at java.awt.EventQueue$4.run(EventQueue.java:674)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.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$9.actionPerformed(MenuBar.java:115)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$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.access$000(EventQueue.java:102)
    at java.awt.EventQueue$3.run(EventQueue.java:662)
    at java.awt.EventQueue$3.run(EventQueue.java:660)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:676)
    at java.awt.EventQueue$4.run(EventQueue.java:674)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.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$9.actionPerformed(MenuBar.java:115)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$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)

该文件仍按预期第二次写入,但是它将在第二次以及以后对writeToFile()的调用中引发此错误。我想知道是什么导致此错误发生。


问题答案:

writer.close();写完后就在打电话。流关闭后,将无法再次写入。通常,实现此目标的方法是将结束状态移至write方法。

public 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();
    }
}

并添加一种方法cleanUp来关闭流。

public void cleanUp() {
     writer.close();
}

这意味着您有责任cleanUp在完成写入文件时确保正在调用。否则,将导致内存泄漏和资源锁定。

编辑 :您可以创建一个新的流要写入文件,通过移动每一次writer进入writeToFile()方法..

 public void writeToFile() {
    FileWriter writer = new FileWriter("status.txt", true);
    // ... Write to the file.

    writer.close();
 }


 类似资料:
  • 我正在开发一个Kafka-Stream应用程序,它将从输入Kafka主题读取消息,过滤不需要的数据并推送到输出Kafka主题。 Kafka流配置: KStream筛选器逻辑: 当开始以上spring的Kafka流应用程序,我得到以下例外。 我们的Kafka Infra团队给了“group.id”必要的权限,使用这个相同的“group.id”,我可以使用其他Kafka消费者应用程序来使用消息,我在“

  • 问题内容: 我正在编写一个简单的程序,该程序使用读取和处理文件内容。 但是当我第二秒钟调用另一个文件名时,出现以下异常: 线程“主”中的异常java.io.IOException:流已关闭 我不知道如何关闭流。我犯了什么错误,该如何解决? 问题答案: 由于您要先关闭流,所以流已关闭 读取文件名后发出的问题。 不要关闭该阅读器,也不要为其创建新的阅读器-只需重用该阅读器即可。但是,请使用其他文件读取

  • 异常: 传递流程 基于上述注释观察并理解异常传递流程: <?php function g1() { throw new \Exception(); yield; } // a2 -> b2 -> (new AsyncTask(g1()))->begin(); function g2() { yield; throw new \Exception(); } //

  • 主要内容:前记,1.processHandlerException方法前记 根据之前的文章方法中的方法返回处理的方法 1.processHandlerException方法 这个方法就是如果出现异常的话, 异常解析器进行处理异常。 先判断是否是注解下的方法, 如果是的话另外处理 -> 判断是否是注解下的方法 这里的主要有3个实现类 1.1注解下的异常 1.2注解下的方法 获取到装填码 获取到出错理由 然后渲染异常的页面 返回空的ModelAndView 1.3解析方

  • 升级到1.9.3+版本后编译失败 主要明显的就是IpUtils.getIp和request的.state报错。 这是因为从v1.9.3版本开始,对项目进行了一些优化,具体优化内容参考:v1.9.3 (opens new window)和v1.9.4 (opens new window)。 新版本的使用方式,参考JustAuth-demo (opens new window) @RequestMap

  • 问题内容: 我目前在关闭应用程序的CTRL-C期间关闭异步协程时遇到问题。下面的代码是我现在所拥有的简化版本: 如果按CTRL-C,会给我以下输出: 我对asyncio的经验不是很丰富,所以我很确定我在这里缺少重要的东西。真正让我头疼的是输出之后的部分。从开始,我必须承认我不知道发生了什么。我查看了其他问题,但无法正常工作。那么,为什么这段代码输出类似的东西?如何干净地关闭协程呢? 谢谢你的帮助!