将进程输出重定向到stdout

Question

我想从Groovy程序中执行foo.bat，并将生成的进程的输出重定向到stdout。Java或Groovy代码示例都可以。

foo.bat可能需要花费几分钟才能运行并生成大量输出，因此我希望在生成后立即查看输出，而不是必须等到该过程完成之后才能立即查看所有输出。

Answer 1

它使用一个类读取执行的程序生成的所有输出，并将其显示在其自己的stdout中。

class StreamGobbler extends Thread {
    InputStream is;

    // reads everything from is until empty. 
    StreamGobbler(InputStream is) {
        this.is = is;
    }

    public void run() {
        try {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line=null;
            while ( (line = br.readLine()) != null)
                System.out.println(line);    
        } catch (IOException ioe) {
            ioe.printStackTrace();  
        }
    }
}

Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("javac");
//output both stdout and stderr data from proc to stdout of this process
StreamGobbler errorGobbler = new StreamGobbler(proc.getErrorStream());
StreamGobbler outputGobbler = new StreamGobbler(proc.getInputStream());
errorGobbler.start();
outputGobbler.start();
proc.waitFor();