Java 字节流实现文件拷贝

利用字节流实现文件拷贝

FileOutputStream（输出流，写入信息）
FileInputStream（输入流，读取信息）

字节流图：

Markdown

代码

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.StringReader;
import java.nio.file.LinkPermission;

public class demo01 {
    public static void main(String[] args) {
        testCopy();
    }

    public static void testCopy(){
        long start = 0 , end = 0;
        start = System.currentTimeMillis();
        Copy("test//demo01.txt","test//demo02.txt","test//demo02.txt");
        end = System.currentTimeMillis();
        System.out.println("完成时间： "+ (end-start)+" ms");
    }

    public static void Copy(String sourceName, String targetName, String redName){
        FileInputStream input = null;
        FileInputStream input2 = null;
        FileOutputStream output = null;
        try {
            input = new FileInputStream(sourceName);//读取文件
            output = new FileOutputStream(targetName);//写入文件
            input2 = new FileInputStream(redName);//读取文件
            int lenth = -1;
            int lenth2 = -1;
            byte[] bytes = new byte[1024];//字节数组来复制，效率更高
            while ((lenth = input.read(bytes))>-1){
                output.write(bytes);
            }
            while ((lenth2 = input2.read(bytes))>-1){
                String str = new String(bytes);
                System.out.println(str);
            }
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            try {
                if (input != null)
                    input.close();
            }catch (IOException e){
                e.printStackTrace();
            }
            try {
                if (output != null)
                    output.close();
            }catch (IOException e){
                e.printStackTrace();
            }

        }
    }
}