Java 应用调用 Linux 控制台程序并交互：实现与注意事项

Process process = Runtime.getRuntime().exec("myConsoleApp");

// 假设 myConsoleApp 需要一个参数 "arg1"
Process process = Runtime.getRuntime().exec(new String[]{"myConsoleApp", "arg1"});

import java.io.IOException;
import java.io.OutputStream;

public class ProcessInputSender {

    public static void sendInput(Process process, String input) throws IOException {
        final OutputStream os = process.getOutputStream();
        os.write(input.getBytes());

        // 模拟回车键
        final String lineSeparator = System.lineSeparator();
        os.write(lineSeparator.getBytes());

        os.flush(); // 确保数据被发送
    }
}

import java.io.IOException;
import java.io.InputStream;

public class ProcessOutputReader {

    public static void readOutput(Process process) throws IOException {
        // 读取标准输出
        final InputStream is = process.getInputStream();
        System.out.println("--- Standard Output ---");
        readStream(is);

        // 读取标准错误
        final InputStream es = process.getErrorStream();
        System.out.println("--- Standard Error ---");
        readStream(es);
    }

    private static void readStream(InputStream is) throws IOException {
        while (true) {
            final int b = is.read();
            if (b == -1) break;
            System.out.print((char) b);
        }
    }
}

#!/bin/bash
echo "Hello from console app!"
read -p "Enter something: " input_val
echo "You entered: $input_val"
if [ "$input_val" == "a" ]; then
    echo "Special action triggered by 'a'!"
else
    echo "No special action."
fi
echo "Console app finished."

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ConsoleAppTrigger {

    public static void main(final String[] args) {
        // 假设外部控制台程序名为 myConsoleApp.sh
        // 确保该脚本在当前工作目录或PATH中可找到，或提供完整路径
        String consoleAppCommand = "./myConsoleApp.sh"; // 或 /path/to/myConsoleApp.sh

        try {
            System.out.println("Attempting to execute: " + consoleAppCommand);
            final Process process = Runtime.getRuntime().exec(consoleAppCommand);

            // 创建一个线程池来并行处理输入输出流
            ExecutorService executor = Executors.newFixedThreadPool(2);

            // 提交任务来读取标准输出
            Future<Void> stdoutReader = executor.submit(() -> {
                readStream("Standard Output", process.getInputStream());
                return null;
            });

            // 提交任务来读取标准错误
            Future<Void> stderrReader = executor.submit(() -> {
                readStream("Standard Error", process.getErrorStream());
                return null;
            });

            // 向外部进程写入输入
            final OutputStream os = process.getOutputStream();
            System.out.println("Sending input 'a' to console app...");
            os.write("a".getBytes());

            // 模拟回车键
            final String lineSeparator = System.lineSeparator();
            os.write(lineSeparator.getBytes());
            os.flush(); // 确保数据被发送
            os.close(); // 关闭输出流，表示不再发送更多输入

            // 等待外部进程完成
            int exitCode = process.waitFor();
            System.out.println("Console app exited with code: " + exitCode);

            // 获取读取线程的结果，确保它们已经完成
            stdoutReader.get();
            stderrReader.get();

            executor.shutdown(); // 关闭线程池

        } catch (IOException e) {
            System.err.println("Error executing console app: " + e.getMessage());
            e.printStackTrace();
        } catch (InterruptedException e) {
            System.err.println("Process interrupted: " + e.getMessage());
            Thread.currentThread().interrupt(); // 重新设置中断状态
        } catch (Exception e) {
            System.err.println("An unexpected error occurred: " + e.getMessage());
            e.printStackTrace();
        }
    }

    /**
     * 辅助方法：从InputStream中读取数据并打印
     * @param streamName 流的名称（用于打印日志）
     * @param is 要读取的InputStream
     */
    private static void readStream(String streamName, InputStream is) {
        try {
            int b;
            StringBuilder output = new StringBuilder();
            while ((b = is.read()) != -1) {
                output.append((char) b);
            }
            if (output.length() > 0) {
                System.out.println("--- " + streamName + " ---");
                System.out.println(output.toString().trim());
            }
        } catch (IOException e) {
            System.err.println("Error reading " + streamName + ": " + e.getMessage());
        } finally {
            try {
                if (is != null) {
                    is.close();
                }
            } catch (IOException e) {
                System.err.println("Error closing " + streamName + ": " + e.getMessage());
            }
        }
    }
}