如何显示使用JAVA 运行UNIX 命令的结果

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ExecDemoSort {
  public static void main(String[] av) throws IOException {

    Runtime r = Runtime.getRuntime();

    Process p;

    p = r.exec("sort sortdemo.txt");

    BufferedReader is = new BufferedReader(new InputStreamReader(p
        .getInputStream()));

    System.out.println("Here is your sorted data:");

    String aLine;
    while ((aLine = is.readLine()) != null)
      System.out.println(aLine);

    System.out.println("That is all, folks!");

 

    return;
  }
}