Question

I with my beginner skils in Java, can’t figure out how to encrypt text. Yes I do know that there are alot of libraries and APIS, but this time I want to do this ny way so I understand everything perfectly.

So my idea and question is how to assign values to characters and later use them (encrypt and decrypt). For example A = 12; B = 13; C = 14; D = 15. So DBAC would be 15131214

So far I made this program that just increases character by one, but I cant figure out how to assign diferent values.

package javaapplication2;

public class JavaApplication2 {
public static void main(String[] args) {
    int b;
    String text = "criptable text";
    char[] textArray = text.toCharArray();

    for(int index=0; index < textArray.length;index++){
        textArray[index]++;

    }

    String done = new String (textArray);
    System.out.println(done);
}
}

Answer 1

You might be looking for something like this?

public class TestType {

public static void main(String[] args) {

    /*
     * Create a Map of replacements
     */
    Map<Character, String> keyMap = new HashMap<Character, String>();
    keyMap.put('a', "12");  keyMap.put('b', "13");
    keyMap.put('c', "14");  keyMap.put('d', "15");
    keyMap.put('e', "16");  keyMap.put('f', "17");
    keyMap.put('g', "18");  keyMap.put('h', "19");
    //Add more key-values for all letter support


    String plainText = "abcdefgh";
    StringBuffer encrypted = new StringBuffer();

    for (char ch : plainText.toCharArray()) {
        /* Form the encrypted string */
        encrypted.append(keyMap.get(ch));

    }

    System.out.println("Encrypted: " + encrypted.toString());

}

}