一、字节流的四种读写数据方式:
package Test;
import java.io.*;
public class Test5 {
public static void main(String[] args) throws IOException {
File f= new File("G:/liu/liu.avi");
long start=System.currentTimeMillis();
test1(f); //最慢
test2(f);
test3(f); //1610
test4(f);//复制耗时:149 最快
long end=System.currentTimeMillis();
System.out.println("复制耗时:"+(end-start));
}
第一种:按字节读取数据
//1.按字节读取数据
private static void test1(File f) throws IOException {
FileInputStream fis=new FileInputStream(f);
FileOutputStream fos=new FileOutputStream("G:/liu/liu1/liu1.avi");
int data=0;
while((data=fis.read())!=-1){
fos.write(data);
}
fis.close();
fos.close();
}
第二种按字节数组读写数据
//2.按字节数组读数据
private static void test2(File f) throws IOException {
FileInputStream fis=new FileInputStream(f);
FileOutputStream fos=new FileOutputStream("G:/liu/liu1/liu2.avi");
byte[] buf=new byte[1024];
int len=0;
while((len=fis.read(buf,0,buf.length))!=-1){
fos.write(buf,0,len);
}
fis.close();
fos.close();
}
第三种:缓冲流按字节读数据
//3.缓冲流按字节读数据
private static void test3(File f) throws IOException {
//1.创建对象
FileInputStream fis=new FileInputStream(f);
BufferedInputStream bis=new BufferedInputStream(fis);
FileOutputStream fos = new FileOutputStream("G:/liu/liu1/liu3.avi");
BufferedOutputStream bos=new BufferedOutputStream(fos);
//2.处理数据
int data=0;
while((data=bis.read())!=-1){
bos.write(data);
}
//3。关闭流
fis.close();
fos.close();
}
第四种:缓冲流按字节数组读数据
//4.缓冲流按字节数组读数据
private static void test4(File f) throws IOException {
//1.创建对象
FileInputStream fis=new FileInputStream(f);
BufferedInputStream bis=new BufferedInputStream(fis);
FileOutputStream fos = new FileOutputStream("G:/liu/liu1/liu3.avi");
BufferedOutputStream bos=new BufferedOutputStream(fos);
//2.处理数据
int len=0;
byte[] buf=new byte[1024];
while((len=bis.read(buf,0,buf.length))!=-1){
bos.write(buf,0,len);
}
//3。关闭流
fis.close();
fos.close();
}