ch.entwine.weblounge.common.impl.util.html.HTMLUtils.java Source code

Introduction

Here is the source code for ch.entwine.weblounge.common.impl.util.html.HTMLUtils.java

Source

/*
 *  Weblounge: Web Content Management System
 *  Copyright (c) 2011 The Weblounge Team
 *  http://weblounge.o2it.ch
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software Foundation
 *  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

package ch.entwine.weblounge.common.impl.util.html;

import org.apache.commons.lang.StringEscapeUtils;

import java.io.StringWriter;

/**
 * Utility class that facilitates dealing with <code>HTML</code> code.
 */
public final class HTMLUtils {

    /**
     * This is a utility class and must not be instantiated.
     */
    private HTMLUtils() {
        // Nothing to do here
    }

    /**
     * <p>
     * Escapes the characters in the <code>String</code> passed and writes the
     * result to the <code>Writer</code> passed.
     * </p>
     * 
     * @param writer
     *          The <code>Writer</code> to write the results of the escaping to.
     *          Assumed to be a non-null value.
     * @param str
     *          The <code>String</code> to escape. Assumed to be a non-null value.
     * 
     * @see #escapeHtml(String)
     */
    public static String escapeHtml(String str) {
        StringWriter writer = createStringWriter(str);
        int len = str.length();
        for (int i = 0; i < len; i++) {
            char c = str.charAt(i);
            if (c > 0x7F) {
                writer.write("&#");
                writer.write(Integer.toString(c, 10));
                writer.write(';');
            } else {
                writer.write(c);
            }
        }
        return writer.toString();
    }

    /**
     * <p>
     * Unescapes the escaped entities in the <code>String</code> passed and writes
     * the result to the <code>Writer</code> passed.
     * </p>
     * 
     * @param writer
     *          The <code>Writer</code> to write the results to; assumed to be
     *          non-null.
     * @param str
     *          The source <code>String</code> to unescape; assumed to be
     *          non-null.
     * @return the unescaped string
     * @see #escapeHtml(String)
     */
    public static String unescape(String str) {
        return StringEscapeUtils.unescapeHtml(str);
    }

    /**
     * Make the StringWriter 10% larger than the source String to avoid growing
     * the writer
     * 
     * @param str
     *          The source string
     * @return A newly created StringWriter
     */
    private static StringWriter createStringWriter(String str) {
        return new StringWriter((int) (str.length() + (str.length() * 0.1)));
    }

}