How to Extract File Extensions in Java with Ease

When dealing with files in Java, extracting their extensions is often necessary. However, instead of writing a custom parser, consider leveraging the utility provided by Apache Commons IO.

Using FilenameUtils.getExtension

The FilenameUtils class offers a convenient method called getExtension that can efficiently extract the file extension from a given input. This method supports both full paths and just file names.

Example Usage

The following code snippet demonstrates how to utilize this method:

import org.apache.commons.io.FilenameUtils;

// ...

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

Maven Dependency

To incorporate this functionality into your Java project, you'll need to add the following dependency to your Maven configuration:

  commons-io
  commons-io
  2.6

Conclusion

FilenameUtils.getExtension from Apache Commons IO provides an effortless solution for extracting file extensions in Java. By leveraging this utility, you can avoid writing your own parser and enjoy the convenience of a built-in method.