org.sventon.util.FileExtensionFilter.java Source code

Introduction

Here is the source code for org.sventon.util.FileExtensionFilter.java

Source

/*
 * ====================================================================
 * Copyright (c) 2005-2012 sventon project. All rights reserved.
 *
 * This software is licensed as described in the file LICENSE, which
 * you should have received as part of this distribution. The terms
 * are also available at http://www.sventon.org.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 * ====================================================================
 */
package org.sventon.util;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang.Validate;
import org.sventon.model.DirEntry;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * File extension filter.
 * Filters out given extension and removes entries with non-matching extension.
 *
 * @author jesper@sventon.org
 */
public final class FileExtensionFilter {

    /**
     * The file extension to filter.
     */
    private final String filterExtension;

    /**
     * Constructor.
     *
     * @param filterExtension File extension to filter (i.e. keep).
     */
    public FileExtensionFilter(final String filterExtension) {
        Validate.notEmpty(filterExtension, "File extension was null or empty");
        this.filterExtension = filterExtension;
    }

    /**
     * Filter a given list of entries.
     *
     * @param entries List of entries to filter.
     * @return List of entries matching given extension.
     */
    public List<DirEntry> filter(final List<DirEntry> entries) {
        final List<DirEntry> dir = Collections.checkedList(new ArrayList<DirEntry>(), DirEntry.class);

        for (final DirEntry entry : entries) {
            final String fileExtension = FilenameUtils.getExtension(entry.getName()).toLowerCase();
            if (filterExtension.equals(fileExtension)) {
                dir.add(entry);
            }
        }
        return dir;
    }
}