Java 创建/复制/遍历删除 文件目录

本文主要记录了使用java创建目录，复制目录，遍历目录及文件，删除目录等。

Java comes with two create directory methods :
 1. File(‘directory’).mkdir()
new File("C:\\Directory1").mkdir();
Create a directory named “Directory1″
 2. File(‘directories’).mkdirs()
new File("C:\\Directory2\\Sub2\\Sub-Sub2").mkdirs()
Create a directory named “Directory2 and all its sub-directories “Sub2″ and “Sub-Sub2″ in one shot.


To delete a directory, you can simply use the File.delete(), but the directory must be empty in order to delete it.

Often times, you may require to perform recursive delete in a directory, which means all it’s sub-directories and files should be delete as well.

完整代码如下：

package org.hnrsc.directory;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class JavaDirectory {

    public static void main(String[] args){
        System.out.println("------------create directory--------------");
        //create directory
        File file = new File("C:\\folder1");
        if(file.mkdir()){
            System.out.println("Directory is created.");
        }else{
            System.out.println("Failed to create directory.");
        }

        //create directories
        File files = new File("C:\\folder2\\folder2-1\\folder2-3");
        if(files.mkdirs()){
            System.out.println("Multiple directories are created");
        }else{
            System.out.println("Failed to create multiple directories.");
        }

        System.out.println("-----------copy folder---------------");
        File srcFolder = new File("C:\\logs");
        File destFolder = new File("C:\\logs-bak");

        //make sure source folder exists
        if(!srcFolder.exists()){
            System.out.println("Directory does not exists.");
            System.exit(0);
        }else{
            try{
                copyFolder(srcFolder,destFolder);
            }catch(IOException e){
                e.printStackTrace();
                System.exit(0);
            }
        }
        System.out.println("-----------traverse directory---------------");
        traverseDir(new File("C:\\logs-bak"));
        System.out.println("-----------delete node--------------");
        deleteNode(new File("C:\\logs-bak"));
    }

    private static void copyFolder(File src, File dest) throws IOException {

        if(src.isDirectory()){
            //if diirectory not exists ,create it
            if(!dest.exists()){
                dest.mkdir();
                System.out.println("Directory copied from " + src +" to " + dest);
            }
            //list all the directory contents
            String[] files = src.list();

            for(String file :files){
                //construct the src and dest file structure
                File srcFile = new File(src,file);
                File destFile = new File(dest,file);

                copyFolder(srcFile,destFile);
            }
        }else{
            //if file, then copy it use bytes stream to support all file types
            InputStream in = new FileInputStream(src);
            OutputStream out = new FileOutputStream(dest);

            byte[] buffer = new byte[1024];
            int len;
            while((len = in.read(buffer)) > 0){
                out.write(buffer,0,len);
            }
            in.close();
            out.close();
        }
    }

    public static void traverseDir(File node){
        System.out.println(node.getAbsoluteFile());

        if(node.isDirectory()){
            String[] subnode = node.list();
            for(String filename : subnode){
                traverseDir(new File(node,filename));
            }
        }
    }

    public static void deleteNode(File node){

        if(node.isDirectory()){

            //directory is empty, then delete it
            if(node.list().length == 0){
                node.delete();
                System.out.println("Directory is deleted: "+ node.getAbsolutePath());
            }else{
                //list all the directory contents
                String files[] = node.list();
                for(String temp:files){
                    //construct the file structure
                    File fileDelete = new File(node,temp);

                    //recursive delete
                    deleteNode(fileDelete);
                }

                //check the dir again , if empty then delete
                if(node.list().length == 0){
                    node.delete();
                    System.out.println("Directory is deleted: "+ node.getAbsolutePath());
                }
            }
        }else{
            //if file then delete it
            node.delete();
            System.out.println("File is deleted : " + node.getAbsolutePath());
        }
    }
}