IO4:Buffered~--java30(02/25/2016)

package com.atguigu.java;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.print.attribute.standard.Destination;

import org.junit.Test;

/* 
* 抽象基类         节点流（文件流）        缓冲流(处理流的一种，可以提高文件处理效率)
* InputStream      FileInputStream        BufferedInputStream
* OutputStream    FileOutputStream       BufferedOutputStream  (flus())
* Reader            FileReader             BufferedReader  (readLine())
* Writer            FileWriter             BufferedWriter  (flus())（bw.newLine()）
*/

public class testBuffered {
    @Test
    public void testBufferedReader(){
        BufferedReader br = null;
        BufferedWriter bw = null;
        try {
            File file = new File("07.txt");
            File file1 = new File("08.txt");
            FileReader fr = new FileReader(file);
            FileWriter fw = new FileWriter(file1);
            br = new BufferedReader(fr);
            bw = new BufferedWriter(fw);
//          char[] c = new char[1024];
//          int len;
//          while((len = br.read(c))!= -1){
//              String str = new String(c, 0, len);
//              System.out.println(str);
//          }
            
            String str;
            while((str = br.readLine()) != null){
//              System.out.println(str);
                bw.write(str);//上面是在一行读出来的，现在写也不会换行，加入新方法
//              System.out.println();//不换行
//              bw.write(str + "\n");//这种方法换行也可以
                bw.newLine();
                bw.flush();
            }
            
        } catch (Exception e) {
            e.printStackTrace();
        }finally{//先关吧
            if(bw != null){
                try {
                    bw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                
            }
            if(br != null){
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                
            }
        }
        
        
    }
    
    @Test
    public void testCopyFile(){
        long start = System.currentTimeMillis();
        String src = "C:\\Users\\xiaotinh\\Desktop\\03.jpg";
        String dest = "C:\\Users\\xiaotinh\\Desktop\\05.jpg";
        copyFile(src, dest);
        long end = System.currentTimeMillis();
        System.out.println("文件复制的时间：" + (end - start));//15ms
        
    }
    //使用缓冲流实现文件的复制的方法
    public void copyFile(String src,String dest){
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            //1.提供读入、写出的文件
            File file1 = new File(src);
            File file2 = new File(dest);
            //2.先创建相应的节点流：FileInputStream、FileOutputStream
            FileInputStream fis = new FileInputStream(file1);
            FileOutputStream fos = new FileOutputStream(file2);
            //3.将创建的节点流的对象作为形参传递给缓冲流的构造器中
            bis = new BufferedInputStream(fis);
            bos = new BufferedOutputStream(fos);
            //4.具体的实现文件复制的操作
            byte[] b = new byte[1024];
            int len;
            while((len = bis.read(b)) != -1){
                bos.write(b, 0, len);
                bos.flush();//最好后面都加一句这个，因为前面几次都写出去了，
                //但是到最后一句的时候，可能没有写满，这时需要清空一下，防止对下次有影响
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
            //5.关闭相应的流
            if(bos != null){
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(bis != null){
                try {
                    bis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    
    
    //使用BufferedInputStream和BufferedOutputStream实现非文本文件的复制
    @Test
    public void testBufferedInputOutputStream(){
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            //1.提供读入、写出的文件
            File file1 = new File("C:\\Users\\xiaotinh\\Desktop\\03.jpg");
            File file2 = new File("C:\\Users\\xiaotinh\\Desktop\\04.jpg");
            //2.先创建相应的节点流：FileInputStream、FileOutputStream
            FileInputStream fis = new FileInputStream(file1);
            FileOutputStream fos = new FileOutputStream(file2);
            //3.将创建的节点流的对象作为形参传递给缓冲流的构造器中
            bis = new BufferedInputStream(fis);
            bos = new BufferedOutputStream(fos);
            //4.具体的实现文件复制的操作
            byte[] b = new byte[1024];
            int len;
            while((len = bis.read(b)) != -1){
                bos.write(b, 0, len);
                bos.flush();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
            //5.关闭相应的流
            if(bos != null){
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(bis != null){
                try {
                    bis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}