使用Process Builder或Apache Commons exec执行外部程序 [英] Executing an external program using process builder or apache commons exec

问题描述

我需要执行一个外部应用程序，该应用程序将返回大数据(需要2个多小时才能完成)，并连续输出数据.

I need to execute an external application which returns large data (takes more than 2 hours to complete ) nand which continuously outputs data.

我需要做的是异步执行该程序并将输出捕获到文件中. 我尝试使用Java流程生成器，但是它似乎仅在程序退出或强制终止时才挂起并返回输出.

What I need to do is execute this program asynchronously and capture the output in a file. I tried using java process builder, however it seems to hang and return output only when the program is exited or forcefully terminated.

我尝试使用流程生成器并修改了一个新线程来捕获输出，但是仍然没有帮助.

I tried to use process builder and spwaned a new thread to capture the output, but still it did not help.

然后，我了解了有关Apache Commons exec的信息，并尝试了相同的操作.但是，这似乎也要花费很长时间，并且返回不同的错误代码(对于相同的输入)

Then I read about apache commons exec and tried the same . however this also seems to be taking a long time and returns different error codes ( for the same input)

CommandLine cmdLine = new CommandLine("/opt/testsimulator");

    DefaultExecuteResultHandler resultHandler = new DefaultExecuteResultHandler();
    ByteArrayOutputStream stdout = new ByteArrayOutputStream();
    PumpStreamHandler psh = new PumpStreamHandler(stdout);
    ExecuteWatchdog watchdog = new ExecuteWatchdog(60*1000);
    Executor executor = new DefaultExecutor();
    executor.setStreamHandler(psh);
    executor.setWatchdog(watchdog);
    try {
        executor.execute(cmdLine);
    } catch (ExecuteException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

任何有帮助的例子或有帮助的例子

Any help or working examples whould be very helpful

推荐答案

呵呵.使用ProcessBuilder应该适合您的配置.例如，以下模式对我有用:

Huh. Using ProcessBuilder should work for your configuration. For example, the following pattern works for me:

ProcessBuilder pb = new ProcessBuilder("/tmp/x");
Process process = pb.start();
final InputStream is = process.getInputStream();
// the background thread watches the output from the process
new Thread(new Runnable() {
    public void run() {
        try {
            BufferedReader reader =
                new BufferedReader(new InputStreamReader(is));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            is.close();
        }
    }
}).start();
// the outer thread waits for the process to finish
process.waitFor();

我正在运行的程序只是一个包含一整行sleep 1和echo行的脚本:

The program that I'm running is just a script with a whole bunch of sleep 1 and echo lines:

#!/bin/sh
sleep 1
echo "Hello"
sleep 1
echo "Hello"
...

从进程读取的线程大约每秒钟吐出一个Hello.

The thread reading from the process spits out a Hello every second or so.

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