FileUtil.java

package pl.piotrsukiennik.whowhen.shared.util;

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 * @author Main
 */
public abstract class FileUtil {

    public static final FilenameFilter CSV_FILE_FILTER = new FilenameFilter() {
        public boolean accept( File dir, String name ) {
            return name.endsWith( ".csv" );
        }
    };

    public static final FileFilter DIRECTORY_FILTER = new FileFilter() {
        public boolean accept( File pathname ) {
            return pathname.isDirectory();
        }
    };


    public static FileFilter getFileFilterForExtensions( String extension, String... extensions ) {
        final StringBuilder regex = new StringBuilder( "(.+)" ).append( extension );
        for ( String ex : extensions ) {
            regex.append( "|" ).append( ex );
        }
        // regex.append(")");
        System.out.println( "REGEX = " + regex.toString() );
        return new FileFilter() {
            private Pattern pattern = Pattern.compile( regex.toString(), Pattern.DOTALL );

            public boolean accept( File pathname ) {
                return pattern.matcher( pathname.getName() ).matches();
            }
        };
    }

    public static List<File> recursivelyListFiles( File rootDir, FileFilter fileFilter ) {
        List<File> files = new ArrayList<File>();
        if ( rootDir != null && rootDir.exists() ) {
            if ( rootDir.isFile() && fileFilter.accept( rootDir ) ) {
                files.add( rootDir );
                return files;
            }
            else if ( rootDir.isDirectory() ) {
                for ( File file : rootDir.listFiles() ) {
                    files.addAll( recursivelyListFiles( file, fileFilter ) );
                }
            }
        }
        return files;
    }

    public static void removeDirectory( File dir ) {
        for ( File f : dir.listFiles() ) {
            if ( f.isDirectory() ) {
                removeDirectory( f );
            }
            else {
                f.delete();
            }
        }
        dir.delete();
    }

    public static void copyFile( File source, File dest ) throws IOException {

        if ( !dest.exists() ) {
            dest.mkdirs();
            dest.createNewFile();
        }
        InputStream in = null;
        OutputStream out = null;
        try {
            in = new FileInputStream( source );
            out = new FileOutputStream( dest );

            // Transfer bytes from in to out
            byte[] buf = new byte[1024];
            int len;
            while ( ( len = in.read( buf ) ) > 0 ) {
                out.write( buf, 0, len );
            }
        }
        finally {
            in.close();
            out.flush();
            out.close();
        }

    }

    public static void copyDirectory( File sourceDir, File destDir ) throws IOException {

        if ( !destDir.exists() ) {
            destDir.mkdir();
        }

        File[] children = sourceDir.listFiles();

        for ( File sourceChild : children ) {
            String name = sourceChild.getName();
            File destChild = new File( destDir, name );
            if ( sourceChild.isDirectory() ) {
                copyDirectory( sourceChild, destChild );
            }
            else {
                copyFile( sourceChild, destChild );
            }
        }
    }

}