Setup
private String FILE_PATH = "com/levelup/java/io/sample.log";
Straight up Java
@Test
public void get_file_extension_with_java () {
String separator = System.getProperty("file.separator");
int indexOfLastSeparator = FILE_PATH.lastIndexOf(separator);
String filename = FILE_PATH.substring(indexOfLastSeparator + 1);
int extensionIndex = filename.lastIndexOf(".");
String fileExtension = filename.substring(extensionIndex + 1);
assertEquals("log", fileExtension);
}
Google Guava
@Test
public void get_file_extension_with_guava () {
String fileExtension = Files.getFileExtension(FILE_PATH);
assertEquals("log", fileExtension);
}
Apache Commons
@Test
public void get_file_extension_with_apache_commons () {
String fileExtension = FilenameUtils.getExtension(FILE_PATH);
assertEquals("log", fileExtension);
}