HTMLTranscoder.java

/**
 * Copyright (c) 2009 - 2010 AppWork UG(haftungsbeschränkt) <e-mail@appwork.org>
 * 
 * This file is part of org.appwork.utils.encoding
 * 
 * This software is licensed under the Artistic License 2.0,
 * see the LICENSE file or http://www.opensource.org/licenses/artistic-license-2.0.php
 * for details
 */
package org.appwork.utils.encoding;

import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

/**
 * @author thomas
 * 
 */
public class HTMLTranscoder {
    private static final HashMap<Character, String> MAP         = new HashMap<Character, String>();
    private static final HashMap<Character, String> MAP_SIMPLE  = new HashMap<Character, String>();
    private static final HashMap<String, Character> MAP_REVERSE = new HashMap<String, Character>();
    static {
        HTMLTranscoder.MAP_SIMPLE.put('<', "<");
        HTMLTranscoder.MAP_SIMPLE.put('>', ">");
        HTMLTranscoder.MAP_SIMPLE.put('&', "&");
        HTMLTranscoder.MAP_SIMPLE.put('"', """);
        HTMLTranscoder.MAP_SIMPLE.put('\n', "<br>");
        HTMLTranscoder.MAP_SIMPLE.put('\r', "<br>");

        HTMLTranscoder.MAP.put('\n', "<br>");
        HTMLTranscoder.MAP.put('\r', "<br>");
        HTMLTranscoder.MAP.put('<', "<");
        HTMLTranscoder.MAP.put('>', ">");
        HTMLTranscoder.MAP.put('&', "&");
        HTMLTranscoder.MAP.put('"', """);
        HTMLTranscoder.MAP.put('\t', "	");
        HTMLTranscoder.MAP.put('!', "!");
        HTMLTranscoder.MAP.put('#', "#");
        HTMLTranscoder.MAP.put('$', "$");
        HTMLTranscoder.MAP.put('%', "%");
        HTMLTranscoder.MAP.put('\'', "'");
        HTMLTranscoder.MAP.put('(', "(");
        HTMLTranscoder.MAP.put(')', ")");
        HTMLTranscoder.MAP.put('*', "*");
        HTMLTranscoder.MAP.put('+', "+");
        HTMLTranscoder.MAP.put(',', ",");
        HTMLTranscoder.MAP.put('-', "-");
        HTMLTranscoder.MAP.put('.', ".");
        HTMLTranscoder.MAP.put('/', "/");
        HTMLTranscoder.MAP.put(':', ":");
        HTMLTranscoder.MAP.put(';', ";");
        HTMLTranscoder.MAP.put('=', "=");
        HTMLTranscoder.MAP.put('?', "?");
        HTMLTranscoder.MAP.put('@', "@");
        HTMLTranscoder.MAP.put('[', "[");
        HTMLTranscoder.MAP.put('\\', "\");
        HTMLTranscoder.MAP.put(']', "]");
        HTMLTranscoder.MAP.put('^', "^");
        HTMLTranscoder.MAP.put('_', "_");
        HTMLTranscoder.MAP.put('`', "`");
        HTMLTranscoder.MAP.put('{', "{");
        HTMLTranscoder.MAP.put('|', "|");
        HTMLTranscoder.MAP.put('}', "}");
        HTMLTranscoder.MAP.put('~', "~");

        // reverse map for decode
        Entry<Character, String> next;
        for (final Iterator<Entry<Character, String>> it = HTMLTranscoder.MAP.entrySet().iterator(); it.hasNext();) {
            next = it.next();
            HTMLTranscoder.MAP_REVERSE.put(next.getValue(), next.getKey());

        }

    }

    /**
     * @param text
     * @return
     */
    public static String encode(final String text) {

        final StringBuilder result = new StringBuilder();
        final StringCharacterIterator iterator = new StringCharacterIterator(text);
        char character = iterator.current();

        String rep = null;
        while (character != CharacterIterator.DONE) {
            rep = HTMLTranscoder.MAP.get(character);
            if (rep == null) {
                result.append(character);
            } else {
                result.append(rep);
            }

            character = iterator.next();
        }
        return result.toString();
    }

    /**
     * 
     * encodes only newline, <>" and &
     * 
     * @param text
     * 
     * @return
     */
    public static String encodeSimple(final String text) {

        final StringBuilder result = new StringBuilder();
        final StringCharacterIterator iterator = new StringCharacterIterator(text);
        char character = iterator.current();
        char lastC = 0;

        String rep = null;
        while (character != CharacterIterator.DONE) {
            if (character == '\n' && lastC == '\r') {
                lastC = character;
                character = iterator.next();
            }
            rep = HTMLTranscoder.MAP_SIMPLE.get(character);
            if (rep == null) {
                result.append(character);
            } else {
                result.append(rep);
            }
            lastC = character;
            character = iterator.next();
        }
        return result.toString();
    }

    public static void main(final String[] args) {
        final String text = "<b>I'm a fat & htmled test</b>";

        final String encoded = HTMLTranscoder.encode(text);
        System.out.println(encoded);
        // final String decoded = HTMLTranscoder.decode(encoded);
        // System.out.println(decoded);
        // System.out.println(decoded.equals(text));
    }

}