如何知道BufferedReader Stream是否已关闭 [英] How to know if a BufferedReader Stream is closed

问题描述

我在Java中有两个线程。

I have two threads in Java.

第一个线程正在关闭一个bufferedreader（ br.close（） ）

First thread is closing a bufferedreader (br.close())

当第二个线程在同一个阅读器上读取时，我得到一个 IOException（Stream Closed）

When the second thread does a read on the same reader I get an IOException (Stream Closed)

即使我使用 br.ready（）

有没有办法知道流是否已经关闭？

Is there a way to know if the stream is already closed?

推荐答案

方法 ready（）将在关闭时抛出异常。但即使您添加了一个封闭的检查方法，只要在调用之间释放锁定（对于 BufferedReader ），读者可能会在您阅读时关闭它。

The method ready() will throw an exception if closed. But even if you added a closed check method, so long as the lock is released between calls (which it is for BufferedReader), the reader might be closed by the time you read it.

我看到三个选项：

1. 用一个包裹你的来电try / catch块来处理已关闭的案例。


2. 创建 BufferedReader 的子类，扩展 close（） 设置你自己的变量，可以用
   检查阅读器是否关闭。这还需要覆盖很多
   方法来执行你想要的关闭阅读器的任何行为，如果你想要它做什么除了抛出 IOException 。


3. 添加一个你自己的锁并用它来关闭阅读器（一个线程）和
   检查缓冲区是否准备就绪并从中读取。您可以直接为检查设置变量，也可以将 ready（）和 read（）调用分组相同的同步块。

1. Wrap your read call with a try/catch block to handle the closed case.
2. Create a subclass of BufferedReader that extends close() to set your own variable that can be used to check to see if the reader is closed. This also requires overriding a lot of methods to do whatever the behavior you want with a closed reader if you want it do something beside throw the IOException.
3. Add a lock of your own and use it to both close the reader (one thread) and check that the buffer is ready and read from it. You can either set a variable directly for the check or just group the ready() and read() calls into the same synchronized block.

这篇关于如何知道BufferedReader Stream是否已关闭的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！