Synnefo

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package gr.ebs.gss.server.webdav;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.util.BitSet;

/**

 *

 * This class is very similar to the java.net.URLEncoder class.

 *

 * Unfortunately, with java.net.URLEncoder there is no way to specify to the

 * java.net.URLEncoder which characters should NOT be encoded.

 *

 * This code was moved from DefaultServlet.java

 *

 * @author Craig R. McClanahan

 * @author Remy Maucherat

 */

public class URLEncoder {

        /**

         *

         */

        protected static final char[] hexadecimal =

        {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',

                'A', 'B', 'C', 'D', 'E', 'F'};

        /**

         * Array containing the safe characters set.

         */

        protected BitSet safeCharacters = new BitSet(256);

        /**

         *

         */

        public URLEncoder() {

                for (char i = 'a'; i <= 'z'; i++)

                        addSafeCharacter(i);

                for (char i = 'A'; i <= 'Z'; i++)

                        addSafeCharacter(i);

                for (char i = '0'; i <= '9'; i++)

                        addSafeCharacter(i);

        }

        /**

         * @param c

         */

        public void addSafeCharacter( char c ) {

                safeCharacters.set( c );

        }

        /**

         * @param path

         * @return the encoded string

         */

        public String encode( String path ) {

                int maxBytesPerChar = 10;

                StringBuffer rewrittenPath = new StringBuffer(path.length());

                ByteArrayOutputStream buf = new ByteArrayOutputStream(maxBytesPerChar);

                OutputStreamWriter writer = null;

                try {

                        writer = new OutputStreamWriter(buf, "UTF8");

                } catch (Exception e) {

                        e.printStackTrace();

                        writer = new OutputStreamWriter(buf);

                }

                for (int i = 0; i < path.length(); i++) {

                        int c = path.charAt(i);

                        if (safeCharacters.get(c))

                                rewrittenPath.append((char)c);

                        else {

                                // convert to external encoding before hex conversion

                                try {

                                        writer.write((char)c);

                                        writer.flush();

                                } catch(IOException e) {

                                        buf.reset();

                                        continue;

                                }

                                byte[] ba = buf.toByteArray();

                                for (int j = 0; j < ba.length; j++) {

                                        // Converting each byte in the buffer

                                        byte toEncode = ba[j];

                                        rewrittenPath.append('%');

                                        int low = toEncode & 0x0f;

                                        int high = (toEncode & 0xf0) >> 4;

                                rewrittenPath.append(hexadecimal[high]);

                                rewrittenPath.append(hexadecimal[low]);

                                }

                                buf.reset();

                        }

                }

                return rewrittenPath.toString();

        }

}