java.net.FileNameMap Interface in Java

java.net.FileNameMap is a Java Interface. FileNameMap interface is a part of the java.net package. FileNameMap provides a mechanism to map between a file name and a MIME type string. We can use FileNameMap getContentTypeFor method to get the MIME type of the specified file.

Syntax:

public interface FileNameMap

Method of java.net.FileNameMap Interface

The FileNameMap Interface consists of only one method named as:

getContentTypeFor(String fileName) Method – It is a part of java.net.FileNameMap interface. As the method name suggests, getContentFor is used to get the MIME type in String format for a specific file.

Syntax:

String getContentTypeFor(String fileName)

Method Parameter: This method has only one parameter which is of String Type.

Method Return Type: It has a String return type and will return the MIME type for the file.

How to invoke getContentTypeFor method?

Step 1: It load fileNameMap from a data file using URLConnection.getFileNameMap() static method

FileNameMap fileNameMap = URLConnection.getFileNameMap();

Step 2: It invokes FileNameMap.getContentTypeFor(String fileName) method and pass on the fileName to get it’s MIME type 

String mimeType = fileNameMap.getContentFor(String nameOfTheFile);

Example: Below is the java program for a better understanding of the FileNameMap interface and then to get the MIME type of the file using FileNameMap getContentTypeFor() method.

Java

// Java program to demsonstrate the
// working of the FileNameMap interface

import java.io.*;
import java.net.*;

class GFG {
    public static void main(String[] args)
    {
        try {
            FileNameMap fileNameMap
                = URLConnection.getFileNameMap();

            // specify all the fileName whose
            // MIME type we need to know
            String firstFileName = "tmp.txt";
            String secondFileName = "profile.png";
            String thirdFileName = "gfg.mp4";

            // call getContentTypeFor() method for each
            // fileName to get it's MIME type , method will
            // return null if fileName is invalid
            String firstFileMimeType = fileNameMap.getContentTypeFor(firstFileName);
            String secondFileMimeType = fileNameMap.getContentTypeFor(secondFileName);
            String thirdFileMimeType = fileNameMap.getContentTypeFor(thirdFileName);

            // print all the MIME types
            System.out.println("Mime type of "
                               + firstFileName + " is "
                               + firstFileMimeType);
            System.out.println("Mime type of "
                               + secondFileName + " is "
                               + secondFileMimeType);
            System.out.println("Mime type of "
                               + thirdFileName + " is "
                               + thirdFileMimeType);
        }
        catch (Exception e) {
            System.out.println("Some Exception "
                               + e.getMessage());
        }
    }
}

Output

Mime type of tmp.txt is text/plain
Mime type of profile.png is image/png
Mime type of gfg.mp4 is video/mp4