java 从指定行读文件，执行系统命令

 import java.util.*;
 import java.io.*;

 public class Example {
     public static void main(String[] args){
         readFile("proxy.txt",0);
         readFile("proxy.txt",1);
         readFile("proxy.txt",4);
         execSystemCmd("notepad"); // windows cmd
         execSystemCmd("ls /home/whucs");
         execSystemCmd("tail -n /home/whucs/vote.py");
         execSystemCmd("wc -l php-fpm.log"); // count lines of a file. 500MB ~ 2s
     }

     public static void readFile(String path, int beginLine) {
         FileInputStream inputStream = null;
         Scanner sc = null;
         try {
             inputStream = new FileInputStream(path);
             sc = new Scanner(inputStream, "UTF-8");
             int begin = 0;
             if (beginLine == 0) beginLine = 1;
             while (sc.hasNextLine()) {
                 begin ++;
                 if (begin >= beginLine) {
                     String line = sc.nextLine();
                     // TODO...
                     System.out.println(line);
                 } else {
                     sc.nextLine();
                 }
             }
             if (begin < beginLine) {
                 System.out.println("error! beginLine > file's total lines.");
             }
             inputStream.close();
             sc.close();
         } catch (IOException e) {
             System.out.println("FileReader IOException!");
             e.printStackTrace();
         }
     }

     public static void execSystemCmd(String cmd) {
         String outPut = null;
         System.out.println("cmd=" + cmd);
         try
         {
             Process p = Runtime.getRuntime().exec(cmd);
             InputStream is = p.getInputStream();
             BufferedReader br = new BufferedReader(new InputStreamReader(is));
             StringBuilder buf = new StringBuilder();
             String line = null;
             while ((line = br.readLine()) != null)    buf.append(line + "\n");
             outPut = buf.toString();
             System.out.printf("outPut = %s",outPut);
         }
         catch (IOException e)
         {
             e.printStackTrace();
         }
     }

 }