Encoding program help

Question

Hello I am trying to make a program to encode or decode an array. I have gotten it to work but only by making many if statements but I don't want it to be that ugly. I am fairly new to programming and am having trouble with the
this method is the one I am having the trouble with It is supposed to compare find thisChar in the encoder array and then convert that to two characters down the array. I know it is not right and I am getting the out of bounds error. If someone could help me solve this I would appreciate it.
      char charMapEnco(char thisChar)
        for (int index =0; index < encoder.length; index++)
           if (thisChar == encoder[index])
               thisChar = encoder[index + 2];
         return thisChar;
        Here is the whole code
public class EncodeDecode
    //Input list of numbers/letters
    private String[] originalList;  
    //Resulting list of encoded numbers/letters
    private String[] encodeList;
    //Resulting list of decoded numbers/letters
    private String[] decodeList;
    private char[] encoder = {'A','B','C','D','E','F','G','H',
        'I','J','K','L','M','N','O','P','Q','R','S','T','U','V',
        'W','X','Y','Z','a','b','c','d','e','f','g','h',
        'i','j','k','l','m','n','o','p','q','r','s','t','u','v',
        'w','x','y','z','0','1','2','3','4','5','6','7','8','9'};
    public EncodeDecode(String[] origList)
        //Assign parameter to instance variable
        originalList = origList;
        //Create another string array of the same size
        encodeList = new String[originalList.length];
        //Do the mapping
        for (int index = 0; index < originalList.length; index++)
            encodeList[index] = encodeConverter(originalList[index]);  
     //Create another string array of the same size
        decodeList = new String[encodeList.length];
        //Do the mapping
        for (int index = 0; index < encodeList.length; index++)
            decodeList[index] = decodeConverter(encodeList[index]);  
    String encodeConverter(String origMix)
        //Start with empty result string
        String result = "";
        //for each character in the origMix
        for (int index = 0; index < origMix.length(); index++)
            //map it to correct number/letter and concat it to the result
            result = result + charMapEnco(origMix.charAt(index));
        //return result string
        return result;
    String decodeConverter(String encoMix)
        //Start with empty result string
        String result = "";
        //for each character in the encoMix
        for (int index = 0; index < encoMix.length(); index++)
            ////map it to correct number/letter and concat it to the result
            result = result + charMapDeco(encoMix.charAt(index));
        //return result string
        return result;
     * This maps one character to one number/letter using the standard
     * mapping. Any chars other than numbers, uppercase or lowercase
     * letters, will be flagged as errors and left unchanged
      char charMapEnco(char thisChar)
        for (int index =0; index < encoder.length; index++)
           if (thisChar == encoder[index])
               thisChar = encoder[index + 2];
         return thisChar;
     * This maps one characeter to one number/letter using the standard
     * mapping. Any chars other than numbers, uppercase or lowercase
     * letters, will be flagged as errors and left unchanged
   char charMapDeco(char thisChar)
    //Get all three lists:
    String[] getEncodeList()
        return encodeList;
    String[] getDecodeList()
        return decodeList;
    String[] getOriginalList()
        return originalList;
}Edited by: ebuffh51 on Feb 5, 2008 8:27 PM

Answer 1

Here's some code to play with
public class Test{
  private static char[] decoded = {'A','B','C','D','E','F','G','H',
        'I','J','K','L','M','N','O','P','Q','R','S','T','U','V',
        'W','X','Y','Z','a','b','c','d','e','f','g','h',
        'i','j','k','l','m','n','o','p','q','r','s','t','u','v',
        'w','x','y','z','0','1','2','3','4','5','6','7','8','9'};
  private char[] encoded;
  public Test(int offset){
    this.encoded = new char[decoded.length];
    System.arraycopy(Test.decoded,0,this.encoded,offset,this.encoded.length-offset);
    System.arraycopy(Test.decoded,Test.decoded.length-offset,this.encoded,0,offset);
  public String encode(String toencode){
    StringBuffer encoded = new StringBuffer();
    for(int i=0;i<toencode.length();i++){
         encoded.append(encodeChar(toencode.charAt(i)));
    return encoded.toString();
  public String decode(String todecode){
    StringBuffer decoded = new StringBuffer();
    return decoded.toString();
  private char encodeChar(char toencode){
    for(int i=0;i<Test.decoded.length;i++){
         if(toencode==Test.decoded){
          return this.encoded[i];
return toencode;
/*private char decodeChar(char todecode){
public static void main(String args[]){
Test t = new Test(7);
String sample = "ABCDEFGHIJKLMNOPQRSTUVWXYZ!?abcdefghijklmnopqrstuvwxyz123456789";
System.out.println("Sample before "+sample);
sample = t.encode(sample);
System.out.println("Sample encoded "+sample);
sample = t.decode(sample);
System.out.println("Sample decoded "+sample);