private static void filenameComponents_() {
     
        String filename = "X:\\JCG\\articles\\org.apache.commons.io.FilenameUtils Example\\notes.txt";
     
        System.out.println("*** File name components ***");
        System.out.println("File name: " + filename);
     
        String prefix = FilenameUtils.getPrefix(filename);
        System.out.println("Prefix: " + prefix);
         
        String path = FilenameUtils.getPath(filename);
        System.out.println("Path: " + path);
         
        String fullPath = FilenameUtils.getFullPath(filename);
        System.out.println("Full path: " + fullPath);
         
        String name = FilenameUtils.getName(filename);
        System.out.println("Name: " + name);
         
        String baseName = FilenameUtils.getBaseName(filename);
        System.out.println("Base name: " + baseName);
         
        String extension = FilenameUtils.getExtension(filename);
        System.out.println("Extension: " + extension);
}

        

public static void usingFilenameUtils() throws IOException {
      String path = "C:\\dev\\project\\file.txt";
      System.out.println("Full Path: " +FilenameUtils.getFullPath(path));
      System.out.println("Relative Path: " +FilenameUtils.getPath(path));
      System.out.println("Prefix: " +FilenameUtils.getPrefix(path));
      System.out.println("Extension: " + FilenameUtils.getExtension(path));
      System.out.println("Base: " + FilenameUtils.getBaseName(path));
      System.out.println("Name: " + FilenameUtils.getName(path));

      String filename = "C:/commons/io/../lang/project.xml";
      System.out.println("Normalized Path: " + FilenameUtils.normalize(filename));
}

        

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

        

public String getExtensionByApacheCommonLib(String filename) {
    return FilenameUtils.getExtension(filename);
}

        

public void testGetExtension() {
        assertEquals(null, FilenameUtils.getExtension(null));
        assertEquals("ext", FilenameUtils.getExtension("file.ext"));
        assertEquals("", FilenameUtils.getExtension("README"));
        assertEquals("com", FilenameUtils.getExtension("domain.dot.com"));
        assertEquals("jpeg", FilenameUtils.getExtension("image.jpeg"));
        assertEquals("", FilenameUtils.getExtension("a.b/c"));
        assertEquals("txt", FilenameUtils.getExtension("a.b/c.txt"));
        assertEquals("", FilenameUtils.getExtension("a/b/c"));
        assertEquals("", FilenameUtils.getExtension("a.b\\c"));
        assertEquals("txt", FilenameUtils.getExtension("a.b\\c.txt"));
        assertEquals("", FilenameUtils.getExtension("a\\b\\c"));
        assertEquals("", FilenameUtils.getExtension("C:\\temp\\foo.bar\\README"));
        assertEquals("ext", FilenameUtils.getExtension("../filename.ext"));
}

        

public boolean isValid(final String value, final ConstraintValidatorContext context) {
    try {
        if (StringUtils.isEmpty(value)) {
            return true; // do not validate empty value there are other constraints for that e.g. @NotNull, @Size etc...
        }

        final Path path = Paths.get(value);

        if (checkIfExists && !path.toFile().exists()) {
            return false;
        }

        final String fileExt = FilenameUtils.getExtension(value);
        return allowableFileExtensions.isEmpty() ||
               !allowableFileExtensions.stream().filter(fileExt::equalsIgnoreCase).findFirst().orElse(StringUtils.EMPTY).isEmpty();

    } catch (final InvalidPathException e) {
        LOGGER.error(e.getMessage(), e);
        return false;
    }
}

        

public Resource transform(HttpServletRequest request, Resource resource, ResourceTransformerChain transformerChain) throws IOException {
    resource = transformerChain.transform(request, resource);

    final String fileName = resource.getFilename();
    final String fileExt = FilenameUtils.getExtension(fileName);
    switch (fileExt) {
        case "js":
        case "json":
        case "css":
        case "html":
            log.trace("format {} supported for Text-Injection", fileExt);
            return transformText(fileName, resource);
        default:
            log.trace("unsupported Resource-Type: {}", fileExt);
            return resource;
    }
}

        

public void exportImage() {
  try {
    File file = IOUtility.selectFileToSave(FileType.IMAGE);
    if (file != null) {
      Rectangle drawingArea = getDrawingArea();
      String extension = FilenameUtils.getExtension(file.getName());
      if (extension.equals("svg")) {
        SVGGraphics2D svgGenerator = IOUtility.getSVGGraphics(drawingArea.getSize());
        paintDrawing(svgGenerator, drawingArea.x, drawingArea.y);
        svgGenerator.stream(new FileWriter(file));
        svgGenerator.dispose();
      } else {
        BufferedImage bi = new BufferedImage(drawingArea.width, drawingArea.height, BufferedImage.TYPE_INT_RGB);
        Graphics g = bi.createGraphics();
        paintDrawing(g, drawingArea.x, drawingArea.y);
        ImageIO.write(bi, extension, file);
        g.dispose();
      }
    }
  } catch (Exception e) {
    e.printStackTrace();
  }
}

        

private void generateChannelApk(final File inputFile, final File outputDir, final String channel, final String alias, final Map<String, String> extraInfo) {
    final String channelName = alias == null ? channel : alias;
    final String name = FilenameUtils.getBaseName(inputFile.getName());
    final String extension = FilenameUtils.getExtension(inputFile.getName());
    final String newName = name + "_" + channelName + "." + extension;
    final File channelApk = new File(outputDir, newName);
    try {
        FileUtils.copyFile(inputFile, channelApk);
        ChannelWriter.put(channelApk, channel, extraInfo);
    } catch (IOException | SignatureNotFoundException e) {
        e.printStackTrace();
    }
}

        

public boolean accept(File file) {
    if (file.isDirectory()) {
        return true;
    }
    String extension = FilenameUtils.getExtension(file.getName());
    if (!extension.isEmpty()) {
        for (FileType ft : fileType) {
            if (ft.contains(extension))
                return true;
        }
    }
    return false;
}