C:\jtest\ary>java lineno < jary.java 

    1 //jary.java -- ary const -- by tsaiwn@csie.nctu.edu.tw
    2 import java.io.*;
    3 import java.awt.*;
    4 import java.awt.event.*;
    5 class jary {
    6 
    7    static int x[ ] = { 1, 2, 3, 4, 5, 6};
    8    
    9    public static void main(String xx[ ]) {
   10       for(int k:x) cout.print(" " +k);
   11       cout.println( );
   12      String y[ ]= { "Hello", "Haha", "You", "There" };
   13       for(int i=0; i < y.length; ++i ) cout.println(y[i]);
   14      int kk[ ][ ] = { {1, 2, 3}, {4, 5, 6, 7, 8}, {9, 10} };
   15       for(int k[ ]:kk) {
   16           for(int n:k) System.out.print(" " +n);
   17           cout.println( );
   18       }
   19    }
   20    static java.io.PrintStream cout = System.out;
   21 }
   22 /***
   23 C:\jtest\ary>javac jary.java
   24 
   25 C:\jtest\ary>java jary
   26  1 2 3 4 5 6
   27 Hello
   28 Haha
   29 You
   30 There
   31  1 2 3
   32  4 5 6 7 8
   33  9 10
   34 
   35 C:\jtest\ary>
   36 ******/


C:\jtest\ary>java lineno < lineno.java

    1 //lineno.java  --- by tsaiwn@csie.nctu.edu.tw
    2 // javac lineno.java
    3 // java lineno < file.name
    4 import java.io.*;
    5 import java.util.*;
    6 class lineno {
    7     static PrintStream cout = System.out;
    8     static BufferedReader br = new BufferedReader(
    9                             new InputStreamReader(System.in) );
   10     public static void main(String xxx[ ]) throws Exception {
   11         String s;
   12         int n = 0;
   13         s = br.readLine( );
   14         while(s != null) {
   15         //while( ! br.eof() ) {
   16              ++n;
   17              cout.printf("%5d %s\n", n, s);
   18              s = br.readLine( );
   19          } // while
   20          cout.printf("\n");
   21      } // main
   22 }

C:\jtest\ary>