(四)IO流之InputStream和OutputStream
阿新 • • 發佈:2018-09-18
exc 24* code ktr lose lis main trac fileinput
InputStream:定義了字節輸入流的抽象類
OutputStream:定義了字節輸出流的抽象類;該類所有方法返回void值
FileInputStream:
FileOutputStream:
package com.tanlei.InputOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; public class FileInputOutputStream { publicstatic void main(String[] args) { try { FileUtil.copyFile(new File("C:\\zhangsan\\tanlei.txt"), new File("D:\\zhangsan.txt")); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } class FileUtil{ public static void copyFile(File src,File dst) throwsIOException { FileInputStream fis=new FileInputStream(src); FileOutputStream fos=new FileOutputStream(dst); long time=System.currentTimeMillis(); int data=-1; while ((data=fis.read())!=-1) { fos.write(data); } fos.close();long time2=System.currentTimeMillis(); System.out.println("共花費+"+(time2-time)); } }
緩沖區優化
read(byte[] b) 方法
byte[] buf=new byte[1024*1024];//創建一個1M大小的緩沖區,用來存放輸入流中的字節數 long time=System.currentTimeMillis(); int data=0;//用來保存實際讀到的字節數 while ((data=fis.read(buf))!=-1) { fos.write(buf,0,data); } fos.close(); long time2=System.currentTimeMillis(); System.out.println("共花費+"+(time2-time));
(四)IO流之InputStream和OutputStream