Question

我试图通过java代码，使用processbuilder来执行Windows的命令（我们可以通过命令提示符执行）。我的程序对“ dir”等命令运行良好，但对“ java -jar”不起作用。当我给'java -jar C：\ mypath \ filename.jar'时，它一直在等待，甚至没有从流中获取任何输入。您能帮上忙吗？注意：如果我们通过命令提示符执行此操作，效果很好。

public byte[] execute(String command) {
        ProcessBuilder builder = new ProcessBuilder();
        LOG.info("Executing the command {} ...", command);

        builder.command("cmd.exe", "/c", command);

        builder.redirectErrorStream(true);

        try {
            Process process = builder.start();
            StringBuffer outStringBuffer = new StringBuffer();
            StreamGobbler streamGobbler = new StreamGobbler(process.getInputStream(), x -> {
                outStringBuffer.append(x).append("\n");
            });
            Future<?> future = Executors.newSingleThreadExecutor().submit(streamGobbler);
            future.get(120, TimeUnit.SECONDS);//Waiting for 120 seconds and throwing error with null.
            int exitCode = process.waitFor();// If we skip prev step, waiting for ever for this process.
            System.out.println("ExitCode:"+exitCode);

            // assert exitCode == 0;
            if (exitCode == 0) {
                LOG.info("Command \'{}\' executed. And response:{}", command, outStringBuffer.toString());
                return outStringBuffer.toString().getBytes();
            } else {
                LOG.error("Command \'{}\' executed. And process exited with exitCode:{}. Response stored:{}.", command,
                        exitCode, outStringBuffer.toString());
                return ("Process exited with exitCode" + exitCode).getBytes();
            }

        } catch (IOException | InterruptedException | ExecutionException | TimeoutException e) {
            LOG.error("Error in execution of command:{}. Details of error:{}.{}", command, e.getMessage(), e);
            return ("Error in execution of command:" + command + ". Details of error:" + e.getMessage() + "." + e)
                    .getBytes();
        }
    }


    public class StreamGobbler implements Runnable {
    private InputStream inputStream;
    private Consumer<String> consumer;

    public StreamGobbler(InputStream inputStream, Consumer<String> consumer) {
        this.inputStream = inputStream;
        this.consumer = consumer;
    }

    @Override
    public void run() {
        new BufferedReader(new InputStreamReader(inputStream)).lines().forEach(consumer);
    }
}

Answer 1

意识到，如果子流程花费的时间太长，则处理Future和流程是错误的。更新了代码以进行处理。

try {
                future.get(120, TimeUnit.SECONDS);
            } catch (TimeoutException e) {
                readerTimedOut = true;
                LOG.info("The Reader for the process did not complete till timeout seconds:{}", 120);
            }
int processTimeOutSeconds = 40;
            if (readerTimedOut) {
                processTimeOutSeconds = 0;
            }
            boolean isProcessTerminated = process.waitFor(processTimeOutSeconds, TimeUnit.SECONDS);

Java中的ProcessBuilder无法执行“ java -jar”命令

1 个答案: