content: /*
   * Copyright 1999,2004 The Apache Software Foundation.
   * 
   * Licensed 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 net.sf.webdav.fromcatalina;
  
  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
  {
      private static org.slf4j.Logger LOG = org.slf4j.LoggerFactory
              .getLogger(URLEncoder.class);
  
  
      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);
          }
          for(char c : "$-_.+!*'(),".toCharArray()){
               addSafeCharacter(c);
          }
      }
  
      public void addSafeCharacter(char c) {
          _safeCharacters.set(c);
      }
  
      public String encode(String path) {
          int maxBytesPerChar = 10;
          // int caseDiff = ('a' - 'A');
          StringBuffer rewrittenPath = new StringBuffer(path.length());
          ByteArrayOutputStream buf = new ByteArrayOutputStream(maxBytesPerChar);
          OutputStreamWriter writer = null;
          try {
              writer = new OutputStreamWriter(buf, "UTF8");
          } catch (Exception e) {
              LOG.error("Error in encode <"+path+">", e);
              writer = new OutputStreamWriter(buf);
          }
  
          for (int i = 0; i < path.length(); i++) {
              int c = (int) 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 = (int) (toEncode & 0x0f);
                      int high = (int) ((toEncode & 0xf0) >> 4);
                      rewrittenPath.append(HEXADECIMAL[high]);
                      rewrittenPath.append(HEXADECIMAL[low]);
                  }
                  buf.reset();
              }
          }
          return rewrittenPath.toString();
      }
  }
  