Java中FileInputStream和FileOutputStream类实现文件夹及文件的复制粘贴

基本思路就是边搜索边复制，这里用的是广度搜索(BFS)

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayDeque;

public class CopyFile {

    public static void main(String[] args) {
        File f1 = new File("kkk");
        File f2 = new File("D:\");
        try {
            getPathBFS(f1,f2);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    /**
     * 用于读和写
     * @param f1 输入流
     * @param f2 输出流
     */
    private static void copyFile(File f1,String f2){
        InputStream in = null;
        OutputStream out = null;
        try {
            in = new BufferedInputStream(new FileInputStream(f1));
            out = new BufferedOutputStream(new FileOutputStream(f2));
            byte by[] = new byte[1024];
            int len = 0;
            while((len = in.read(by))!=-1){
                out.write(by, 0, len);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            if(in!=null){
                try {
                    in.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if(out != null){
                try {
                    out.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
    /**
     * 用于搜索
     * @param f1 目标文件
     * @param f2 复制到的目标
     * @throws IOException
     */
    private static void getPathBFS(File f1,File f2) throws IOException {
        //运用队列进行广度搜索
        ArrayDeque<File> deque = new ArrayDeque<File>();
        //用于存储复制目标文件
        ArrayDeque<File> dequeCopy = new ArrayDeque<File>();
        //第一个File实例入队
        deque.offer(f1);
        //创建第一个文件夹
        f2 = new File(f2,f1.getName());
        dequeCopy.offer(f2);
        //队列为空时停止
        while(!deque.isEmpty()){
            //取队头
            File[] ff = deque.peek().listFiles();
            File copyFiledir = dequeCopy.peek();
            //创建文件夹
            copyFiledir.mkdir();
            //出队
            deque.poll();
            dequeCopy.poll();
            for(int i=0;i<ff.length;i++){
                //如果是目标文件夹入队
                if(ff[i].isDirectory()){
                    //复制文件夹入队
                    File temp = new File(copyFiledir,ff[i].getName());
                    dequeCopy.push(temp);
                    deque.push(ff[i]);
                }else{
                    //复制到相应文件夹
                    copyFile(ff[i],copyFiledir.getAbsolutePath()+"\"+ff[i].getName());
                }
            }
        }
    }

}