通过 PsExec 时程序输出丢失
(这是我的同事在其他地方发布的一个问题,但我想我会把它贴在这里,看看我是否可以吸引不同的受众。
大家好,我正在测试编写一个小型java应用程序的可能性,该应用程序将使用Psexec来启动远程作业。在测试将java程序的stdin和stdout绑定到psexec的过程中,我遇到了一个奇怪的错误。
我的测试程序是一个基本的回声程序。它启动一个线程从 stdin 读取,然后将读取输出直接传送回 stdout。当在本地计算机上运行时,而不是从psexec运行时,它工作得很好。完全符合预期。
但是,当我第一次从 PsExec 调用它时,输入直接通过管道传输到 stdout 中时,它会丢失。使该 bug 真正令人眼花缭乱的是,只有在输入第一次直接通过管道传输到 stdout 时,它才会丢失。如果将输入字符串追加到另一个字符串,则工作正常。字符串文本或字符串变量。但是,如果输入字符串直接发送到 stdout,则不会通过。第二次它被发送到stdout时,它通过很好 - 每次之后。
我对这里发生的事情完全不知所措。我试图测试我能想到的每一个可能的错误。我没有想法。我错过了一个还是这只是psexec内部的东西?
这是有问题的代码,它有三个类(其中一个类实现了一个接口,该接口是单个函数 interace)。
主类:
public class Main {
public static void main(String[] args) {
System.out.println("Starting up.");
CReader input = new CReader(new BufferedReader(
new InputStreamReader(System.in)));
CEcho echo = new CEcho();
input.addInputStreamListener(echo);
input.start();
System.out.println("Successfully started up. Awaiting input.");
}
}
CReader 类,它是从 stdin 读取的线程:
public class CReader extends Thread {
private ArrayList<InputStreamListener> listeners =
new ArrayList<InputStreamListener>();
private boolean exit = false;
private Reader in;
public CReader(Reader in) {
this.in = in;
}
public void addInputStreamListener(InputStreamListener listener) {
listeners.add(listener);
}
public void fireInputRecieved(String input) {
if(input.equals("quit"))
exit = true;
System.out.println("Input string has made it to fireInputRecieved: "
+ input);
for(int index = 0; index < listeners.size(); index++)
listeners.get(index).inputRecieved(input);
}
@Override
public void run() {
StringBuilder sb = new StringBuilder();
int current = 0, last = 0;
while (!exit) {
try {
current = in.read();
}
catch (IOException e) {
System.out.println("Encountered IOException.");
}
if (current == -1) {
break;
}
else if (current == (int) '\r') {
if(sb.toString().length() == 0) {
// Extra \r, don't return empty string.
continue;
}
fireInputRecieved(new String(sb.toString()));
sb = new StringBuilder();
}
else if(current == (int) '\n') {
if(sb.toString().length() == 0) {
// Extra \n, don't return empty string.
continue;
}
fireInputRecieved(new String(sb.toString()));
sb = new StringBuilder();
}
else {
System.out.println("Recieved character: " + (char)current);
sb.append((char) current);
last = current;
}
}
}
}
CEcho 类,它是将其管道传输回 stdout 的类:
public class CEcho implements InputStreamListener {
public void inputRecieved(String input) {
System.out.println("\n\nSTART INPUT RECIEVED");
System.out.println("The input that has been recieved is: "+input);
System.out.println("It is a String, that has been copied from a " +
"StringBuilder's toString().");
System.out.println("Outputting it cleanly to standard out: ");
System.out.println(input);
System.out.println("Outputting it cleanly to standard out again: ");
System.out.println(input);
System.out.println("Finished example outputs of input: "+input);
System.out.println("END INPUT RECIEVED\n\n");
}
}
最后,这是程序输出:
>psexec \\remotecomputer "C:\Program Files\Java\jre1.6.0_05\bin\java.exe" -jar "C:\Documents and Settings\testProram.jar" PsExec v1.96 - Execute processes remotely Copyright (C) 2001-2009 Mark Russinovich Sysinternals - www.sysinternals.com Starting up. Successfully started up. Awaiting input. Test Recieved character: T Recieved character: e Recieved character: s Recieved character: t Input string has made it to fireInputRecieved: Test START INPUT RECIEVED The input that has been recieved is: Test It is a String, that has been copied from a StringBuilder's toString(). Outputting it cleanly to standard out: Outputting it cleanly to standard out again: Test Finished example outputs of input: Test END INPUT RECIEVED