File


File

Java file class is an abstract representation of directory pathnames and file pathnames.

Syntax for declaring java.io.File class is as follows:

public class File extends Object implements Serializable, Comparable

For a given java file, the pathname might be relative or absolute. There are various methods in a file class to work with directories and files, including creating a newer file or directory, deletion and renaming any file or directory, listing data and contents of a directory, etc.

Different formats are available for directory names and file names; therefore, only a string is not adequate for naming them.

Here are some more things to know about the Java file class:

  • A pathname in a string form or abstract can be relative or absolute. You can get the parent of an abstract pathname by invoking the class method called getParent().
  • First, it is essential to create the File class object by passing the directory name or the filename. Further, a file system might implement a few restrictions to operations on the actual object of the file system, like writing, reading, and executing. All these restrictions are termed access permissions.
  • File class instances are immutable, and therefore, after being created, the abstract pathname of the file object cannot be altered.

Constructors of Java File class:

  • File (File parent, String child): It creates a new file instance using the parent abstract pathname and the pathname string of the child class.
  • File (String pathname): It creates a new file instance after it converts the provided pathname string into an abstract pathname.
  • File (String parent, String child): It creates a new file instance using the pathname string of parent and the child classes.
  • File (URL uri): It create a new file instance after it converts the file URL into an abstract pathname.

Example :

import java.io.*; public class FileDemo { public static void main(String[] args) { try { File file = new File("knowledge2life.txt"); if (file.createNewFile()) { System.out.println("New File is created!"); } else { System.out.println("File already exists."); } } catch (IOException e) { e.printStackTrace(); } } }

OUTPUT:

New File is created!