来自互联网 ：

既高效又好用才是王道！

import java.io.IOException;  
import java.io.FileInputStream;  
import java.io.InputStreamReader;  
import java.io.BufferedReader;  
import java.io.OutputStreamWriter;  
import java.io.PrintWriter;  
import java.io.StreamTokenizer;  
import java.util.ArrayList;  
import java.util.Collections;  
  
public class Main  
{  
    public static final boolean DEBUG = false;  
      
    public StreamTokenizer tokenizer;  
    public BufferedReader cin;  
    public PrintWriter cout;  
      
    public void init()  
    {  
        try {  
            if (DEBUG) {  
                cin = new BufferedReader(new InputStreamReader(  
                        new FileInputStream("d:\\OJ\\uva_in.txt")));  
            } else {  
                cin = new BufferedReader(new InputStreamReader(System.in));  
            }  
            cout = new PrintWriter(new OutputStreamWriter(System.out));  
            tokenizer = new StreamTokenizer(cin);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
      
    public String next()  
    {  
        try {  
            tokenizer.nextToken();  
            if (tokenizer.ttype == StreamTokenizer.TT_EOF)  
                return null;  
            else if (tokenizer.ttype == StreamTokenizer.TT_NUMBER) {  
                return String.valueOf((int)tokenizer.nval);  
            } else if (tokenizer.ttype == StreamTokenizer.TT_WORD) {  
                return tokenizer.sval;  
            } else return null;  
        } catch (Exception e) {  
            e.printStackTrace();  
            return null;  
        }  
    }  
      
      
    public void solve(String s)  
    {  
        
    }  
      
    public static void main(String[] args)   
    {  
        
    }  
}  

ACM中Java高效输入输出封装