IO字节流四种方式复制文件

package com.qyh.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

/*
 * 字节流四种方式复制文件
 * 基本字节流一次读取一个字节
 * 基本字节流一次读取一个字节数组
 * 高效字节流一次读取一个字节
 * 高效字节流一次读取一个字节数组
 */

public class CopyImageDemo {
    public static void main(String[] args) throws IOException {
        method1("d:\兔子.jpg","copy1.jpg");
        method2("d:\兔子.jpg","copy2.jpg");
        method3("d:\兔子.jpg","copy3.jpg");
        method4("d:\兔子.jpg","copy4.jpg");
    }
    
    
    //高效字节流一次读取一个字节数组
    private static void method4(String srcString,String destString ) throws IOException {
        //封装数据源
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcString));
        //封装目的地
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destString));
        
        byte[] bys = new byte[1024];
        int len = 0;
        while((len=bis.read(bys))!=-1) {
            bos.write(bys, 0, len);
        }
        bos.close();
        bis.close();
        
    }
    
    
    // 高效字节流一次读取一个字节
    private static void method3(String srcString , String destString ) throws IOException {
        //封装数据源
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcString));
        //封装目的地
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destString));
        
        int by = 0;
        while((by=bis.read())!=-1) {
            bos.write(by);
        }
        bos.close();
        bis.close();
    }

    //基本字节流一次读取一个字节数组
    private static void method2(String srcString , String destString) throws IOException {
        //封装数据源
        FileInputStream fis = new FileInputStream(srcString);
        //封装目的地
        FileOutputStream fos = new FileOutputStream(destString);
        
        byte[] bys = new byte[1024];
        int len = 0;
        while((len=fis.read(bys))!=-1) {
            fos.write(bys, 0, len);
        }
        fos.close();
        fis.close();
        
        
    }

    // 基本字节流一次读取一个字节
    private static void method1(String srcString,String destString) throws IOException {
        //封装数据源
        FileInputStream fis = new FileInputStream(srcString);
        //封装目的地
        FileOutputStream fos = new FileOutputStream(destString);
        
        int by = 0;
        while((by=fis.read())!=-1) {
            fos.write(by);
            
        }
        fos.close();
        fis.close();                    
    }

}