CODEWITHSUNDEEP
javaiofile-listing
Ariyan
Ariyan

Reputation: 15158

Fast listing files in a directory and all of its subdirectories

I need to find all files in a directory and all of its subdirectories (except some).
Currently I'm using this method:

public  static Collection<File> listFiles(File directory,FilenameFilter filter,boolean recurse){
    Vector<File> files = new Vector<File>();
    File[] entries = directory.listFiles();
    if(entries!=null){
        for (File entry : entries){
            if (filter == null || filter.accept(directory, entry.getName())){
                    files.add(entry);
            }

            if (recurse && entry.isDirectory()){
                    files.addAll(listFiles(entry, filter, recurse));
            }
        }
    }
    return files;
}

and using it like this: 

        this.foundFiles=listFiles(new File(this.BaseDirectory), new FilenameFilter() {
            public boolean accept(File dir, String name) {
                boolean res=true;
                if(name.endsWith(".pdf")){
                    if(!dir.getPath().endsWith("done")){
                        if((workingFile!=null && (dir.getPath().equals(workingFile.getParent()) && name.equals(workingFile.getName())))){
                            res=false;
                        }else{
                            try {
                                ArrayList<String> AuthFolders = DB.getGroupAuthFoldersArray();
                                for(String folder:AuthFolders){
                                    if(dir.getPath().startsWith(BaseDirectory+File.separator+folder)){
                                        res=true;
                                        break;
                                    }else{
                                        res=false;
                                    }
                                }
                            } catch (SQLException ex) {
                                Logger.getLogger(scanner.class.getName()).log(Level.SEVERE, null, ex);
                                res=false;
                            } catch (InterruptedException ex) {
                                Logger.getLogger(scanner.class.getName()).log(Level.SEVERE, null, ex);
                                res=false;
                            }
                        }
                    }else{
                        res=false;
                    }
                }else{
                    res=false;
                }
                return res;
            }
        }, true);

But this is too slow! I have about 3000 files in the directory and it takes 10-15 mins (!!) for this method to find them all.

How Can I do this fast?
I'm thinking about using org.apache.commons.io.FileUtils.listfiles method. Is there a faster way?

Thanks

Upvotes: 3

Views: 5721

Answers (2)

Andrew Thompson
Andrew Thompson

Reputation: 168825

} catch (SQLException ex) {

This does not belong in a class intended to do a directory listing!

Upvotes: 1

dogbane
dogbane

Reputation: 274542

Use Files.walkFileTree in Java 7, which is faster than listFiles because it uses streaming. Read the tutorial for more information.

Upvotes: 9

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