用BufferedRead和BufferedWrite来复制和粘贴

package Zuoye01;

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.io.Reader;
import java.io.Writer;

public class Copy {


    public static void main(String[] args) {
        
        System.out.println(System.getProperty("file.encoding"));
        
        //复制和粘贴   用BufferRead 和 BufferWrite 
        
        //复制应该先读取   输入  文件 => 程序
        Reader r = null;
        BufferedReader er = null;
        
        //再输出 应该从程序写   粘贴    程序 => 文件
        
        Writer w = null;
        BufferedWriter ew = null;
        //找到要读取的文件地址
        
        try {
            r = new FileReader("D:/MyDemo/Demo.txt");
            
            er = new BufferedReader(r);
            //要写一下要复制到哪里的地址
            try {
                w = new FileWriter("D:/MyDemo/t.txt");
                
                ew = new BufferedWriter(w);
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            
            
            //读取 的时候可以  用Buffere的ReadLine方法  一行的读效率会比较高
            String line = null;
            try {
                while((line = er.readLine())!=null) {
                    //这里的line是字符串，所以可以直接这样写:
                    //调用BufferedWrite的Write 把line字符串传进去
                    ew.write(line);
                    
                    ew.flush();
                    
                    ew.newLine();
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            try {
                ew.close();
                w.close();
                er.close();
                r.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            
            
            
            
        }
    }
    
    
    
    
    
}