FileUtil.java

/*
 * Copyright (c) 2002-2014, Mairie de Paris
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice
 *     and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright notice
 *     and the following disclaimer in the documentation and/or other materials
 *     provided with the distribution.
 *
 *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * License 1.0
 */
package fr.paris.lutece.util.file;

import fr.paris.lutece.portal.service.util.AppPropertiesService;

import org.apache.commons.lang.StringUtils;

/**
 * Utility class for files
 */
public final class FileUtil
{
    private static final String PROPERTY_ALLOWED_IMAGES_EXTENSIONS = "portal.files.allowedImagesExtentions";
    private static final String PROPERTY_ALLOWED_HTML_EXTENSIONS = "portal.files.allowedHtmlExtentions";
    private static final String DEFAULT_IMAGES_EXTENSION = "gif,png,jpg,jpeg,bmp";
    private static final String DEFAULT_HTML_EXTENSION = "html,htm,xhtml";
    private static final String CONSTANT_POINT = ".";
    private static final String CONSTANT_COMMA = ",";

    /**
     * Private constructor
     */
    private FileUtil( )
    {
    }

    /**
     * Check if the extension of the file is an image extension
     * 
     * @param strImageFileName
     *            The file name to check
     * @return True if the extension is correct, false otherwise
     */
    public static boolean hasImageExtension( String strImageFileName )
    {
        String strImagesExtentions = AppPropertiesService.getProperty( PROPERTY_ALLOWED_IMAGES_EXTENSIONS, DEFAULT_IMAGES_EXTENSION );

        return hasExtension( strImageFileName, strImagesExtentions );
    }

    /**
     * Check if a file has a valid html extension
     * 
     * @param strFileName
     *            The file name to check
     * @return True if the file name is valid, false otherwise
     */
    public static boolean hasHtmlExtension( String strFileName )
    {
        String strImagesExtentions = AppPropertiesService.getProperty( PROPERTY_ALLOWED_HTML_EXTENSIONS, DEFAULT_HTML_EXTENSION );

        return hasExtension( strFileName, strImagesExtentions );
    }

    /**
     * Check if a file name match extensions in a given list
     * 
     * @param strFileName
     *            The file name to check
     * @param strAllowedExtensions
     *            The comma separated list of allowed extensions
     * @return True of the extension of the file exists in the extension list
     */
    private static boolean hasExtension( String strFileName, String strAllowedExtensions )
    {
        int nIndex = strFileName.lastIndexOf( CONSTANT_POINT );

        if ( ( nIndex >= 0 ) && ( strFileName.length( ) > ( nIndex + 2 ) ) )
        {
            String strExtension = strFileName.substring( nIndex + 1 );

            if ( StringUtils.isNotEmpty( strExtension ) )
            {
                for ( String strAllowedExtention : strAllowedExtensions.split( CONSTANT_COMMA ) )
                {
                    if ( StringUtils.equalsIgnoreCase( strExtension, strAllowedExtention ) )
                    {
                        return true;
                    }
                }
            }
        }

        return false;
    }
}