在Eclipse中运行外部程序

Question

我可以通过下面的代码在Eclipse中打印外部程序的输出(可以在网上找到，不是我的)。我希望能够将命令传递给程序，然后打印程序的输出，但我不知道如何将命令传递给程序。如有任何建议，将不胜感激，谢谢！

代码：

String line;
Process p = Runtime.getRuntime().exec("Z:/LPCXpresso/test10/Debug/arm-none-eabi-readelf.exe");
BufferedReader bri = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader bre = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while ((line = bri.readLine()) != null) {
     System.out.println(line);
}
bri.close();
while ((line = bre.readLine()) != null) {
     System.out.println(line);
}
bre.close();
p.waitFor();

Answer 1

首先，我建议使用ProcessBuilder而不是Runtime.getRuntime().exec(...)

其次，为了能够与启动的进程的不同流进行交互，您需要并发地执行此操作，即为每个流创建一个自己的线程，您可以在其中与其进行交互。

下面是一个示例代码，它演示了与windows cmd.exe中命令行提示符的交互

public static void main(String... args) throws Exception {

    ProcessBuilder pb = new ProcessBuilder("cmd.exe");
    Process proc = pb.start();

    // handle each of proc's streams in a separate thread
    ExecutorService handlerThreadPool = Executors.newFixedThreadPool(3);


    handlerThreadPool.submit(new Runnable() {
        @Override
        public void run() {
            // we want to write to the stdin of the process
            BufferedWriter stdin = new BufferedWriter(
                new OutputStreamWriter(proc.getOutputStream()));

            // read from our own stdin so we can write it to proc's stdin
            BufferedReader myStdin = 
            new BufferedReader(new InputStreamReader(System.in));
            String line = null;
            try {
                do {
                    line = myStdin.readLine();
                    stdin.write(String.format("%s%n", line));
                    stdin.flush();
                } while(! "exit".equalsIgnoreCase(line));
            } catch(IOException e) {
                e.printStackTrace();
            }
        }
    });



    handlerThreadPool.submit(new Runnable() {
        @Override
        public void run() {
            // we want to read the stdout of the process
            BufferedReader stdout = new BufferedReader(
                new InputStreamReader(proc.getInputStream()));
            String line;
            try {
                while(null != (line = stdout.readLine())) {
                    System.out.printf("[stdout] %s%n", line);
                }
            } catch(IOException e) {
                e.printStackTrace();
            }
        }
    });

    handlerThreadPool.submit(new Runnable() {
        @Override
        public void run() {
            // we want to read the stderr of the process
            BufferedReader stderr = new BufferedReader(
                new InputStreamReader(proc.getErrorStream()));
            String line;
            try {
                while(null != (line = stderr.readLine())) {
                    System.err.printf("[stderr] %s%n", line);
                }
            } catch(IOException e) {
                e.printStackTrace();
            }
        }
    });

    // wait for the process to terminate
    int exitCode = proc.waitFor();
    System.out.printf("Process terminated with exit code %d%n", exitCode);
    handlerThreadPool.shutdown();
}

您可以在启动进程之前使用ProcessBuilder#redirectErrorStream(true)将进程stderr重定向到stdout，这样就只有两个线程，一个用于输入，一个用于输出