1 import java.util.*;
2 import java.io.*;
3
4 public class Example {
5 public static void main(String[] args){
6 readFile("proxy.txt",0);
7 readFile("proxy.txt",1);
8 readFile("proxy.txt",4);
9 execSystemCmd("notepad"); // windows cmd
10 execSystemCmd("ls /home/whucs");
11 execSystemCmd("tail -n /home/whucs/vote.py");
12 execSystemCmd("wc -l php-fpm.log"); // count lines of a file. 500MB ~ 2s
13 }
14
15 public static void readFile(String path, int beginLine) {
16 FileInputStream inputStream = null;
17 Scanner sc = null;
18 try {
19 inputStream = new FileInputStream(path);
20 sc = new Scanner(inputStream, "UTF-8");
21 int begin = 0;
22 if (beginLine == 0) beginLine = 1;
23 while (sc.hasNextLine()) {
24 begin ++;
25 if (begin >= beginLine) {
26 String line = sc.nextLine();
27 // TODO...
28 System.out.println(line);
29 } else {
30 sc.nextLine();
31 }
32 }
33 if (begin < beginLine) {
34 System.out.println("error! beginLine > file's total lines.");
35 }
36 inputStream.close();
37 sc.close();
38 } catch (IOException e) {
39 System.out.println("FileReader IOException!");
40 e.printStackTrace();
41 }
42 }
43
44 public static void execSystemCmd(String cmd) {
45 String outPut = null;
46 System.out.println("cmd=" + cmd);
47 try
48 {
49 Process p = Runtime.getRuntime().exec(cmd);
50 InputStream is = p.getInputStream();
51 BufferedReader br = new BufferedReader(new InputStreamReader(is));
52 StringBuilder buf = new StringBuilder();
53 String line = null;
54 while ((line = br.readLine()) != null) buf.append(line + "\n");
55 outPut = buf.toString();
56 System.out.printf("outPut = %s",outPut);
57 }
58 catch (IOException e)
59 {
60 e.printStackTrace();
61 }
62 }
63
64 }
