/* ***** BEGIN LICENSE BLOCK *****
    * Version: MPL 1.1/GPL 2.0/LGPL 2.1
    *
    * The contents of this file are subject to the Mozilla Public License Version
    * 1.1 (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.mozilla.org/MPL/
    *
    * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is "SMS Library for the Java platform".
   *
   * The Initial Developer of the Original Code is Markus Eriksson.
   * Portions created by the Initial Developer are Copyright (C) 2002
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  package org.marre.util;
  
  import java.util.Random;
  
  /***
   * Various functions to encode and decode strings.
   * 
   * @author Markus Eriksson
   */
  public final class StringUtil
  {
      private static final char[] RANDOM_CHARS = "abcdefghijklmnopqrstuvwxyz1234567890".toCharArray();
  
      private static Random myRandom = new Random();
  
      /***
       * This class isn't intended to be instantiated.
       */
      private StringUtil()
      {
      }
  
      /***
       * 
       * @param stringTable
       * @param text
       * @return
       */
      public static int findString(String[] stringTable, String text)
      {
          if (stringTable != null)
          {
              for (int i = 0; i < stringTable.length; i++)
              {
                  if ((stringTable[i] != null) && (stringTable[i].equals(text)))
                  {
                      return i;
                  }
              }
          }
          return -1;
      }
  
      /***
       * Converts a byte array to a string with hex values.
       * 
       * @param theData
       *            Data to convert
       * @return the encoded string
       */
      public static String bytesToHexString(byte[] theData)
      {
          StringBuffer hexStrBuff = new StringBuffer(theData.length * 2);
  
          for (int i = 0; i < theData.length; i++)
          {
              String hexByteStr = Integer.toHexString(theData[i] & 0xff).toUpperCase();
              if (hexByteStr.length() == 1)
              {
                  hexStrBuff.append("0");
              }
              hexStrBuff.append(hexByteStr);
          }
  
          return hexStrBuff.toString();
     }
 
     /***
      * Converts a byte to a string with hex values.
      * 
      * @param theByte
      *            Byte to convert
      * @return the encoded string
      */
     public static String byteToHexString(byte theByte)
     {
         StringBuffer hexStrBuff = new StringBuffer(2);
 
         String hexByteStr = Integer.toHexString(theByte & 0xff).toUpperCase();
         if (hexByteStr.length() == 1)
         {
             hexStrBuff.append("0");
         }
         hexStrBuff.append(hexByteStr);
 
         return hexStrBuff.toString();
     }
 
     /***
      * Converts a string of hex characters to a byte array.
      * 
      * @param theHexString
      *            The hex string to read
      * @return the resulting byte array
      */
     public static byte[] hexStringToBytes(String theHexString)
     {
         byte[] data = new byte[theHexString.length() / 2];
 
         for (int i = 0; i < data.length; i++)
         {
             String a = theHexString.substring(i * 2, i * 2 + 2);
             data[i] = (byte) Integer.parseInt(a, 16);
         }
 
         return data;
     }
 
     /***
      * Method intToString.
      * 
      * Converst an integer to nChars characters
      * 
      * @param value
      *            Integer value
      * @param nChars
      *            Number of chars to represent the "value"
      * @return String The string representing "value"
      */
     public static String intToString(int value, int nChars)
     {
         String strValue = Integer.toString(value);
         StringBuffer strBuf = new StringBuffer(nChars);
 
         for (int i = strValue.length(); i < nChars; i++)
         {
             strBuf.append('0');
         }
         strBuf.append(strValue);
 
         return strBuf.toString();
     }
 
     /***
      * Generates a random string of the given length.
      * 
      * "abcdefghijklmnopqrstuvwxyz1234567890"
      * 
      * @param length
      * @return A random string
      */
     public static String randString(int length)
     {
         StringBuffer sb = new StringBuffer(length);
 
         for (int i = 0; i < length; i++)
         {
             sb.append(RANDOM_CHARS[myRandom.nextInt(RANDOM_CHARS.length)]);
         }
 
         return sb.toString();
     }
 }