我在“克隆”InputStream 时遇到问题。
这不起作用:
InputStream is = ClassLoader.getSystemResourceAsStream("myResource");
但这有效:
InputStream is = new BufferedInputStream(new FileInputStream("/afas.cfg"));
我的代码是:
// Create a piped input stream for one of the readers.
PipedInputStream in = new PipedInputStream();
// Create a tee-splitter for the other reader.(from apache commons io)
TeeInputStream tee = new TeeInputStream(is, new PipedOutputStream(in));
// Create the two buffered readers.
BufferedReader br1 = new BufferedReader(new InputStreamReader(tee));
BufferedReader br2 = new BufferedReader(new InputStreamReader(in));
// Do some interleaved reads from them.
System.out.println("One line from br1:");
System.out.println(br1.readLine());
System.out.println();
System.out.println("Two lines from br2:");
System.out.println(br2.readLine());
System.out.println(br2.readLine());
System.out.println();
System.out.println("One line from br1:");
System.out.println(br1.readLine());
System.out.println();
问题发生在第一次 br1.readLine()
调用时。它只是卡在 PipedInputStream.awaitSpace()
处并处于无限循环中。
PipedStreams 仅适用于线程吗?这意味着当写入 PipedOutputStreams 时,PipedInputStream 将“唤醒”
无论如何,我必须做什么才能完成这项工作?
最佳答案
这是对管道流的滥用。它们旨在由不同的线程使用。它们不会像您在这里使用它们一样工作,因为有一个 4k 缓冲区,并且写入器在填满时会阻塞。来自 Javadoc :
Attempting to use both objects from a single thread is not recommended, as it may deadlock the thread.
就我个人而言,自 1997 年 5 月以来,我从未遇到过这些管道流的有效用途。当时我使用过一次,并立即将其取出以支持队列。
关于java - TeeInputStream 和 PipedStream 在任何情况下都不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20493479/