Help with Interface, FileFilter/FileNameFilter

Question

I need some help with FileFilter/FileNameFilter i a part of a search engine.
If you type "-s" as argument + suffixes you want to filter, then they are added to a list as you can see...But how to use a filter? I know that i need a new class that implements FileFilter, but how is it supposed to look, and how do i use in my particular application? i should use accept as its required by the filename filter, yes?
can you please write the whole class as i'm quite sure its not that long...and how to use in my app...
And please comment other things in the code if you find any errors...thanks!
//Viktor from Sweden!
import java.io.File;
import java.util.LinkedList;
    This class prints the paths of all files (if -d flag i set),
    also recursively if -r flag is set.
<p>
    You can also filter files by writing -s flag and suffixes.
public class PrintNonDirectories {
        @param args Flags:
    <p>
        -d: Searches specified directory.
    <p>
        -r: Searches recursively.
    <P>
        -s: Filtering specified file extensions.
    public static void main (String[] args) {
        // Creates a list of suffixes.
        LinkedList <String> suffixes = new LinkedList <String>();
        File inputFile = new File(".");
        // Set the flags to false by default.
        boolean recursive = false;
        boolean directory = false;
        boolean suffix = false;
        // Check all arguments.
        for (int i = 0; i<args.length; i++) {
            if (args.equals("-d")) {
if (!directory) {
// Check if "-d" is followed by a valid path.
if (i+1 < args.length && !args[i+1].startsWith("-")) {
directory = true;
String someDir = args[i+1];
inputFile = new File(someDir);
i++;
else {
System.out.println("'-d' must be followed by a valid path");
System.exit(0);
else {
System.out.println("You wrote '-d' too many times");
System.exit(0);
else if (args[i].equals("-r")) {
if (!recursive) {
recursive = true;
else {
System.out.println("You wrote '-r' too many times");
System.exit(0);
else if (args[i].equals("-s")) {
if (!suffix) {
suffix = true;
// Check if "-s" is followed by valid file-extensions.
if (i+2>args.length || args[i+1].startsWith("-")) {
System.out.println("You must write at least one extension/file suffix");
System.exit(0);
else {
// Add suffixes.
for (i = i+1; i<args.length && !args[i].startsWith("-"); i++) {
suffixes.add(args[i]);
else {
System.out.println("You wrote '-s' too many times");
System.exit(0);
else {
System.out.println("Wrong argument");
System.exit(0);
if (inputFile.isDirectory()) {
listFiles(inputFile, recursive);
else {
System.out.println("Not a directory");
// Method lists the path of all files.
private static void listFiles (File f, boolean recursive) {
File[] filesInDir = f.listFiles();
for (File FileInDir : filesInDir) {
if (FileInDir.canRead()) {
if (FileInDir.isFile()) {
System.out.println(FileInDir.getPath());
} else if (recursive) {
listFiles(FileInDir, true);
else {
System.out.println("A file could not be read, you may not have access to the file");

Answer 1

Yes, i know that i must implement the accept method, but how do i use the list that i got from my file, to add all the suffixes?
i've read like
return filname.toLowerCase().endsWith(".jpg")
but how do i get from my list to use like,
return filname.toLowerCase().endsWith(".txt")||filname.toLowerCase().endsWith(".doc")
and so on?
shoud i use a constructor to get my suffixes list?
should i use a for loop to try for all the diffrent file extensions each time?
smthn like
public class SuffixFilter implements FilenameFilter {
    public SuffixFilter(LinkedList<String> suffixes) {
    public boolean accept (File dir, String name){
        for(int i = 0; i<suffixes.size(); i++)
                if(name.endsWith("suffixes.get(i))
                        return true;
                 else
                        return false;
{code}