我想问题是,你只读取InputStream而不读取ErrorStream。您还必须小心并行读取两个流。可能发生的情况是,当前从输出流传输的数据填充OS缓冲区,您的exec命令将自动暂停,以便读者有机会清空缓冲区。但该程序仍将等待输出处理。因此,挂起发生。
您可以创建一个单独的类来处理在输入和错误流如下,
public class ReadStream implements Runnable {
String name;
InputStream is;
Thread thread;
public ReadStream(String name, InputStream is) {
this.name = name;
this.is = is;
}
public void start() {
thread = new Thread (this);
thread.start();
}
public void run() {
try {
InputStreamReader isr = new InputStreamReader (is);
BufferedReader br = new BufferedReader (isr);
while (true) {
String s = br.readLine();
if (s == null) break;
System.out.println ("[" + name + "] " + s);
}
is.close();
} catch (Exception ex) {
System.out.println ("Problem reading stream " + name + "... :" + ex);
ex.printStackTrace();
}
}
}
您使用它是如下的方式,
String cmd= "cmd /C si viewhistory --fields=revision --project="+fileName;
Process p = Runtime.getRuntime().exec(cmd) ;
s1 = new ReadStream("stdin", p.getInputStream());
s2 = new ReadStream("stderr", p.getErrorStream());
s1.start();
s2.start();
p.waitFor();
} catch (Exception e) {
e.printStackTrace();
} finally {
if(p != null)
p.destroy();
}
看看[ProcessBuilder](http://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html)。如果没有输出,'readLine'将永远阻塞。这是一个更简单的API来完成这种事情。 – RNJ
如果没有输出,'readLine'将永远阻塞。 – assylias
@assylias:我如何检查是否没有输出? – user1688404