Parse special characters: Servlet/xml

[Salman Moha]

Hi experts,
I have this requirement where I need to do implement XOR logic with the following.

 
Time = decrypt("���������","�����������");
 
it works fine with alpha numeric like -- decrypt("qr35%&5675","reg345*453"); But not working with special characters like ("���������","�����������");
 
Here is my decrypt code
 
private String decrypt(String taCryptText, String taKeyText)
      {
            int i = 0;
            int iCryptLength = 0;
            int iCryptTextLength = 0;
            int iKeyLength = 0;
            int iKeyTextLength = 0;
            int iDelta = 0;
            int iTemp = 0;
            char cTemp = 0;
            char cTemp0 = 0;
            String sTemp = null;
            String sCryptText = null;
            String sKeyText = null;
            String sPlainText = null;
            String taPlainText = null;
            StringBuffer sbTemp = null;
            int iCrypt[] = null;
            int iCryptBuffer[] = null;
            int iKey[] = null;
            int iKeyBuffer[] = null;
            boolean bNumericKey = false;
            boolean bNumericCrypt = false;
 
            sCryptText = taCryptText;
            sKeyText = taKeyText;
 
            iCryptTextLength = sCryptText.length();
            iKeyTextLength = sKeyText.length();
 
            System.out.println("Key is :"+sKeyText);
 
            System.out.println("sCryptText:"+sCryptText);
            System.out.println("iKeyTextLength:"+iKeyTextLength);
 
            // Find out if the crypttext is numeric:
            if (numericP(iCryptTextLength, sCryptText))
            {
                  bNumericCrypt = true;
                  System.out.println("The crypt text is numeric.");
                  // Fill the crypt array:
                  iCrypt = new int[iCryptTextLength];                      
                  // More than enough for the crypt integers.
                  i = 0;
                  while (i < iCryptTextLength)
                  {
                        cTemp = 0;
                        sbTemp = new StringBuffer();
                        while (cTemp != ' ' && i < iCryptTextLength)
                        {
                              try
                              {
                                    cTemp = sCryptText.charAt(i);
                              }
                              catch (StringIndexOutOfBoundsException e0)
                              {
                                    System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (crypt).");
                              }
                              if (cTemp != ' ')
                              {
                                    sbTemp.append(cTemp);
                              }
                              i++;
                        }
                        iCrypt[iCryptLength] = Integer.parseInt(sbTemp.toString());
                        iCryptLength++;
                  }
            }
            else
            {
                  iCryptLength = iCryptTextLength;
                  System.out.println("The crypt text is not numeric, iCryptLength = " + iCryptLength + ".");
            }
 
            // Find out if the key is numeric:
            if (numericP(iKeyTextLength, sKeyText))
            {
                  bNumericKey = true;
                  System.out.println("The key is numeric.");
                  // Fill the key array:
                  iKey = new int[iKeyTextLength];
                  i = 0;
                  while (i < iKeyTextLength)
                  {
                        cTemp = 0;
                        sbTemp = new StringBuffer();
                        while (cTemp != ' ' && i < iKeyTextLength)
                        {
                              try
                              {
                                    cTemp = sKeyText.charAt(i);
                              }
                              catch (StringIndexOutOfBoundsException e1)
                              {
                                    System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (key).");
                              }
                              if (cTemp != ' ')
                              {
                                    sbTemp.append(cTemp);
                              }
                              i++;
                        }
                        try
                        {
                              iTemp = Integer.parseInt(sbTemp.toString());
                        }
                        catch (NumberFormatException e1a)
                        {
                              System.out.println("Caught NumberFormatException in decrypt() (key).");
                              break;
                        }
                        iKey[iKeyLength] = iTemp;
                        iKeyLength++;
                  }
            }
            else
            {
                  iKeyLength = iKeyTextLength;
                  System.out.println("The key is not numeric, iKeyLength = " + iKeyLength + ".");
            }
 
            if (iCryptLength < iKeyLength)
            {
                  if (bNumericCrypt)
                  {
                        System.out.println("Ignoring excess key digits.");
                  }
                  else
                  {
                        System.out.println("Ignoring excess key characters.");
                  }
            }
            else
            {
                  if (iKeyLength < iCryptLength)
                  {
                        System.out.println("Key is shorter than crypttext: repeating the key.");
                        //      lblMessage.setText("Key is shorter than crypttext: repeating the key.");
                        if (bNumericKey)
                        {
                              // Repeat the key as necessary to make it long enough.
                              iKeyBuffer = new int[iKeyLength];                                  // Need to stash the key characters someplace
                              for (i = 0; i < iKeyLength; i++)                                   // while we get more memory for the array.
                              {
                                    iKeyBuffer[i] = iKey[i];
                              }
                              iKey = new int[iCryptLength];                                      // Expand the key array.
                              for (i = 0; i < iKeyLength; i++)
                              {
                                    iKey[i] = iKeyBuffer[i];
                              }
                              for (i = iKeyLength; i < iCryptLength; i++)
                              {
                                    iKey[i] = iKey[i - iKeyLength];
                              }
                        }
                        else
                        {
                              sbTemp = new StringBuffer(sKeyText);
                              for (i = iKeyLength; i < iCryptLength; i++)
                              {
                                    try
                                    {
                                          cTemp = sbTemp.charAt(i - iKeyLength);
                                    }
                                    catch (StringIndexOutOfBoundsException e2)
                                    {
                                          System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e2).");
                                    }
                                    sbTemp.append(cTemp);
                              }
                              sKeyText = sbTemp.toString();
                              iKeyLength = sKeyText.length();
                        }
                  }
                  else
                  {
                        // They are equal in length, do nothing.
                  }
            }
            // Begin the decryption.
            sbTemp = new StringBuffer();
            for (i = 0; i < iCryptLength; i++)
            {
                  if (bNumericKey)
                  {
                        if (bNumericCrypt)
                        {
                              iTemp = iCrypt[i] ^ iKey[i];
                        }
                        else
                        {
                              try
                              {
                                    cTemp = sCryptText.charAt(i);
                              }
                              catch (StringIndexOutOfBoundsException e3)
                              {
                                    System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e3).");
                              }
                              iTemp = cTemp ^ iKey[i];
                        }
                  }
                  else
                  {
                        if (bNumericCrypt)
                        {
                              try
                              {
                                    cTemp = sKeyText.charAt(i);
                              }
                              catch (StringIndexOutOfBoundsException e4)
                              {
                                    System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e4).");
                              }
                              iTemp = iCrypt[i] ^ cTemp;
                        }
                        else
                        {
                              try
                              {
                                    cTemp = sCryptText.charAt(i);
                                    cTemp0 = sKeyText.charAt(i);
                              }
                              catch (StringIndexOutOfBoundsException e5)
                              {
                                    System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e5) , i = " + i + ".");
                              }
                              iTemp = cTemp ^ cTemp0;
                        }
                  }
                  sbTemp.append((char) iTemp);
            }
            sTemp = sbTemp.toString();
            System.out.println("sTemp " + sTemp );
 
            if (unprintableP(iCryptLength, sTemp))
            {
                  System.out.println("Unprintable decrypted text, writing " + iCryptLength + " characters as numeric code.");
                  //lblMessage.setText("Unprintable decrypted text, writing " + iCryptLength + " characters as numeric code.");
                  sbTemp = new StringBuffer();
                  for (i = 0; i < iCryptLength; i++)
                  {
                        try
                        {
                              iTemp = sTemp.charAt(i);
                        }
                        catch (StringIndexOutOfBoundsException e6)
                        {
                              System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e6).");
                        }
 
                        if (i == iCryptLength - 1)
                        {
                              sbTemp.append(iTemp);
                        }
                        else
                        {
                              sbTemp.append(iTemp + " ");
                        }
                  }
                  taPlainText=sbTemp.toString();
            }
            else
            {
                  System.out.println("Printable decrypted text, writing " + iCryptLength + " characters.");
                  //      lblMessage.setText("Printable decrypted text, writing " + iCryptLength + " characters.");
                  taPlainText=sTemp;
            }
            return taPlainText;
      }                                      
      boolean numericP(int iTextLength, String sText)
      {
            boolean r = true;
            int i = 0;
            char cTemp = 0;
            int iRunLength = 0;
            int iMaxRunLength = 0;
 
            for (i = 0; i < iTextLength; i++)
            {
                  try
                  {
                        cTemp = sText.charAt(i);
                  }
                  catch (StringIndexOutOfBoundsException e7)
                  {
                        System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e7).");
                  }
                  if (cTemp != ' ')
                  {
                        if (cTemp < 48 || cTemp > 57)
                        {
                              r = false;
                              break;                                                          // Break out of for loop.
                        }
                        else
                        {
                              if (cTemp > 47 && cTemp < 58)
                              {
                                    // We have a decimal digit.
                                    iRunLength++;
                              }
                        }
                  }
                  else
                  {
                        // We have a space:                                                // Detect delimiting spaces
                        if (iRunLength > iMaxRunLength)
                        {
                              iMaxRunLength = iRunLength;
                        }
                        iRunLength = 0;
                  }
            }                                                                     // End of for.
 
            if (iRunLength > iMaxRunLength)                                       // Catch the case where the space
            {                                                                     // comes at the end of the string.
                  iMaxRunLength = iRunLength;
            }
 
            if (iMaxRunLength > 3)                                                // It's not text that happens to to be
            {                                                                     // a string (or strings) of digits.
                  r = false;
            }
 
            return r;
      }
 
      boolean unprintableP(int iLength, String sText)
      {
            boolean r = false;
            int i = 0;
            char cTemp = 0;
 
            for (i = 0; i < iLength; i++)
            {
                  try
                  {
                        cTemp = sText.charAt(i);
                  }
                  catch (StringIndexOutOfBoundsException e8)
                  {
                        System.out.println("Caught StringIndexOutOfBoundsException in decrypt() (e8).");
                  }
 
                  if (cTemp < 32 || cTemp == 127)
                  {
                        if (cTemp != 9 && cTemp != 10 && cTemp != 12 && cTemp != 13)
                        {
                              r = true;
                              System.out.println("Unprintable on character " + (int) cTemp);
                              break;                                                          // Break out of for loop.
                        }
                  }
            }
 
            return r;
      }
 

Experts please let me know how to handle special characters in this decrypt method.

[Campbell Ritchie]

Don't know, and the code posted is too long to read properly, but please check all these if blocks. You are checking whether the characters are in a particular range. Please go through those ranges and see that they don't restrict you to using a particular subgroup of character values. Also have a look at the Character class, which has all sorts of useful methods for checking types of character.

[Martijn Verburg]

I might also be worth looking at an Unicode/ASCII encoding issues.