Java利用高效缓冲字符流来快速copy文件

代码:

package cn1;

import java.io.*;
import java.util.Date;

public class Copy1 {
    public static void main(String[] args) {
        //算出程序开始的时间
        Date date = new Date();
        long starTime = date.getTime();
        BufferedReader reader = null;
        BufferedWriter writer = null;
        try {
            //创建一个高效缓冲输入流
            reader = new BufferedReader(new FileReader("hello.txt"));
            //创建一个高效缓冲输出流
            writer = new BufferedWriter(new FileWriter("hello1.txt"));
            //创建一个读一行的变量
            String line = null;
            while ((line = reader.readLine()) != null){
                writer.write(line);
                writer.newLine();//换行
                writer.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (writer != null){
                    writer.close();
                }
                if (reader != null){
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        Date date1 = new Date();
        long endTime = date1.getTime();
        long runTime = endTime - starTime;
        System.out.println("程序运行了"+runTime+"毫秒");
    }
}