[20160731]read a file and print it on the screen

 //read a file and print it on the screen
 import java.io.*;

 public class MyPrintStreamTest2{
 public static void main(String[] args) {
 String filename = args[0];    // firsttime to see!!!
 if(filename!=null){ list(filename,System.out); }
 }

 public static void list(String filename,PrintStream ps){
 try
 {
 BufferedReader br = new BufferedReader( new FileReader(filename) );
 String s = null;
 while ((s=br.readLine())!=null) {
 ps.println(s);
 }
 br.close();
 }

 catch(IOException e)
 {
 ps.println("reading file error!");
 }

 }
 }