如何将Process的输入/输出流复制到系统对应的流程？

import java.io.IOException;

public class ProcessStreamCopyExample {
    public static void main(String[] args) {
        try {
            // 创建新的ProcessBuilder对象
            ProcessBuilder processBuilder = new ProcessBuilder("system_command");

            // 获取当前进程的输入/输出流
            Process currentProcess = processBuilder.start();
            ProcessInputStreamThread inputThread = new ProcessInputStreamThread(currentProcess.getInputStream());
            ProcessOutputStreamThread outputThread = new ProcessOutputStreamThread(currentProcess.getOutputStream());

            // 获取系统对应流程的输入/输出流
            Process systemProcess = processBuilder.start();
            ProcessInputStreamThread systemInputThread = new ProcessInputStreamThread(systemProcess.getInputStream());
            ProcessOutputStreamThread systemOutputThread = new ProcessOutputStreamThread(systemProcess.getOutputStream());

            // 启动系统对应的流程
            systemInputThread.start();
            systemOutputThread.start();

            // 复制输入/输出流
            inputThread.start();
            outputThread.start();

            // 等待线程执行完毕
            inputThread.join();
            outputThread.join();
            systemInputThread.join();
            systemOutputThread.join();
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

    static class ProcessInputStreamThread extends Thread {
        private final InputStream inputStream;

        public ProcessInputStreamThread(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        @Override
        public void run() {
            try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
                String line;
                while ((line = reader.readLine()) != null) {
                    // 处理输入流数据
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    static class ProcessOutputStreamThread extends Thread {
        private final OutputStream outputStream;

        public ProcessOutputStreamThread(OutputStream outputStream) {
            this.outputStream = outputStream;
        }

        @Override
        public void run() {
            try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream))) {
                // 写入输出流数据
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}