一、程式碼及解釋

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;


public class Main {
    public static int getValidLength
 
(byte[] bytes){//獲得快取區中實際位元組長
        int i = 0;
        if (null == bytes || 0 == bytes.length)
            return i ;
        for (; i < bytes.length; i++) {
            if (bytes[i] == '\0'||bytes[i] == '\n')
                break;
        }
        return i-1 ;
    }
    public static void main(String[] args) throws
 
 IOException {
        File f1=new File("E:\\mytext.txt");//原始檔
        File f2=new File("E:\\mynewtxt.txt");//目標檔案

        InputStream is=System.in;//從鍵盤輸入，以位元組流
        FileOutputStream os=new FileOutputStream(f1,true);//追加的形式
        byte []bt=new byte[1024];//快取位元組陣列
        is.read(bt);//讀入陣列
        os.write(bt,0
 
,getValidLength(bt));//寫入時忽略的空的位元組

        BufferedReader br=new BufferedReader(new FileReader(f1));//讀原始檔流
        BufferedWriter wr=new BufferedWriter(new FileWriter(f2));//寫原始檔流
        String s1=null;//快取字串
        while((s1=br.readLine())!=null) {//寫
            wr.write(s1);//寫
        }
        br.close();
        wr.close();

    }

}

二、結果