get file extension in java

Download Apache Commons IO package
https://commons.apache.org/proper/commons-io/download_io.cgi

/**
 * @author lautturi.com
 * Java example: get file extension in java
 */

import java.util.*;
import apache.commons.io.FilenameUtils;

public class Lautturi {

	public static void main(String[] args) {

		String ext1 = FilenameUtils.getExtension("/path/to/file/foo.txt"); // returns "txt"
		String ext2 = FilenameUtils.getExtension("bar.exe");
	}
}