举一个StreamGobbler的例子

StreamGobbler是Java中一个处理进程I/O流的类。下面是一个使用StreamGobbler的例子，它启动一个进程并从其标准输出流中读取数据：

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

public class ProcessRunner {
    public static void main(String[] args) {
        try {
            Runtime runtime = Runtime.getRuntime();
            Process process = runtime.exec("ping www.baidu.com");

            InputStream inputStream = process.getInputStream();
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

            StreamGobbler streamGobbler = new StreamGobbler(bufferedReader);
            Thread thread = new Thread(streamGobbler);
            thread.start();

            int exitCode = process.waitFor();
            System.out.println("Exited with error code " + exitCode);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static class StreamGobbler implements Runnable {
        private BufferedReader bufferedReader;

        public StreamGobbler(BufferedReader bufferedReader) {
            this.bufferedReader = bufferedReader;
        }

        public void run() {
            try {
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

这个例子启动一个ping命令并将其输出打印到控制台。StreamGobbler类实现了Runnable接口，它在单独的线程中读取进程的标准输出流并将其输出到控制台。在主线程中，我们使用Runtime.exec()方法启动进程，然后创建一个StreamGobbler实例来读取进程的输出流。最后，我们等待进程退出并打印其错误代码。