package zhao;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Vector;


public class Test 
{ 
    
     public static void main(String args[]) 
     { 
         Vector<String> v = new Vector<String>();
         BufferedReader bufin = null;
         BufferedWriter bufout = null;
        try {
            bufin = new BufferedReader(new FileReader("D:\\eclipse\\test.txt"));
            String s = null;
            while((s=bufin.readLine()) != null) {
                v.add(s);
            }
            bufin.close();
            String [] array = v.toArray(new String[v.size()]);
            for(int i=array.length-1;i>=0;i-- ) {
                
                System.out.println(array[i]);
            }
            bufout = new BufferedWriter(new FileWriter("D:\\eclipse\\testin.txt"));
            for(String s1:v) {
                bufout.write(s1+"\n");
            }
            bufout.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(bufin!=null) {
                try {
                    bufin.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(bufout!=null) {
                try {
                    bufout.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
         
         
     } 
}

------解决方案--------------------
蹭分^_^

Java code

import java.io.*;
import java.util.*;
 
public class Test{
    
    public void doSomething(String inFileName,String outFileName) throws IOException{
        File inFile = new File(inFileName);
        File outFile = new File(outFileName);
        
        BufferedReader br = new BufferedReader(new FileReader(inFile));
        BufferedWriter bw = new BufferedWriter(new FileWriter(outFile));
        
        
        String s = null;
        Vector<String> list = new Vector<String>();
        while((s = br.readLine()) != null){
            list.add(s);
        }
        br.close();
        
        Collections.reverse(list);
        
        int line = 1;
        for(String tmp:list){
            System.out.println(tmp);
            bw.write((line++) + "\t" + tmp);
            bw.newLine();           
        }        
        bw.flush();
        bw.close(); 
    }
    
    public static void main(String[] args){
        try {
            new Test().doSomething("C:/in.txt","C:/out.txt");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}