Java Program to Get the File Extension

Difficulty Level : Basic
Last Updated : 07 Jan, 2021

Getting the file extension of the file is through Java using File class of Java i.e. probeContentType() method. The File class is Java’s representation of a file or directory pathname. The File class contains several methods for working with the pathname, deleting and renaming files, creating new directories, listing the contents of a directory, and determining several common attributes of files and directories.

probeContentType() Method

The probeContentType() is a method that comes predefined in the Java File class. The parameter to this method is passed the path of the file.

Parameters: A path of the file.

Return value: It returns a string(extension).

In Java, we can get the filename by –

File file = new File(“/home/mayur/GFG.java”);
String fileName = file.getName();

Below is the implementation of the problem statement:

Java

// Java Program to Get the File Extension
  
import java.io.*;
import java.nio.file.Files;
  
public class GFG {
    public static void main(String[] args)
    {
        // File location
        File f = new File("/home/mayur/GFG.java");
  
        // If file exists
        if (f.exists()) {
            String fileType = "Undetermined";
            String fileName = f.getName();
            String extension = "";
            int i = fileName.lastIndexOf('.');
  
            if (i > 0) {
                extension = fileName.substring(i + 1);
            }
            try {
                fileType
                    = Files.probeContentType(f.toPath());
            }
            catch (IOException ioException) {
                System.out.println(
                    "Cannot determine file type of "
                    + f.getName()
                    + " due to following exception: "
                    + ioException);
            }
  
            // Print Extension
            System.out.println(
                "Extension used for file is -> " + extension
                + " and is probably " + fileType);
        }
        else {
            System.out.println("File does not exist!");
        }
    }
}

Output:

Java Program to Get the File Extension

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.

My Personal Notes

Related Articles

Java