68 Java - Directory Operations

Directory in Java

A directory is a File which can contain a list of other files and directories. You use File object to create directories, to list down files available in a directory. For complete detail, check a list of all the methods which you can call on File object and what are related to directories.

Creating Directories

There are two useful File utility methods, which can be used to create directories −

• The mkdir() method creates a directory, returning true on success and false on failure. Failure indicates that the path specified in the File object already exists, or that the directory cannot be created because the entire path does not exist yet.

• The mkdirs() method creates both a directory and all the parents of the directory.

Example to Create Directory in Java

Following example creates "/tmp/user/java/bin" directory −

package com.codeheap;

import java.io.File;

public class DirectoryTest {
   public static void main(String args[]) {
      String dirname = "/tmp/user/java/bin";
      File directory = new File(dirname);

      // Create directory now.
      directory.mkdirs();

      // create new file object
      File file = new File("/tmp/user/java/bin");

      System.out.println(file.exists());      
   }
}

Output

Compile and execute the above code to create "/tmp/user/java/bin" folders.

true

Note − Java automatically takes care of path separators on UNIX and Windows as per conventions. If you use a forward slash (/) on a Windows version of Java, the path will still resolve correctly.

Listing (Reading) Directories

You can use list() method provided by File object to list down all the files and directories available in a directory as follows −

Example to Read (List) a Directory in Java

package com.codeheap;

import java.io.File;

public class DirectoryTest {

   public static void main(String[] args) {
      File file = null;
      String[] paths;
  
      try {      
         // create new file object
         file = new File("/tmp");

         // array of files and directory
         paths = file.list();

         // for each name in the path array
         for(String path:paths) {
            // prints filename and directory name
            System.out.println(path);
         }
      } catch (Exception e) {
         // if any error occurs
         e.printStackTrace();
      }
   }
}

Output

This will produce the following result based on the directories and files available in your /tmp directory −

user

Deleting Directories

You can use delete() method provided by File object to delete a directory as follows −

Example to Delete a Directory in Java

package com.codeheap;

import java.io.File;

public class DirectoryTest {

   public static void main(String[] args) {
      File file = new File("/tmp/user/java/bin");
      if(file.exists()) {
         boolean success = file.delete();

         if (success) {
            System.out.println("The directory has been successfully deleted."); 
         }else {
            System.out.println("The directory deletion failed.");
         }        
      }else {
         System.out.println("The directory is not present."); 
      }
   }
}

Output

This will produce the following result based on the directories and files available in your /tmp directory −

The directory has been successfully deleted.