Runtime.getRuntime（）。exec（cmd）挂起

Runtime.getRuntime（）。exec（cmd）挂起

我想问题是您只在读取InputStream而没有在读取ErrorStream。您还必须注意并行读取两个流。可能发生这种情况，当前从输出流中管道传输的数据已填满OS缓冲区，您的exec命令将自动挂起，以使您的阅读器有机会清空缓冲区。但是程序仍将等待输出处理。因此，发生挂起。

您可以创建一个单独的类来处理输入流和错误流，如下所示，

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 ();        }    }}

使用方式如下：

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();}