从字符串中删除字符

Question

I'm encrypting the text by using Vigenere cipher. Usually, I this method the key has to shorter than the original text, but what if the key is longer than the text? Can someone help me figure out ho to make the key equal to the text

NOTE: I already know how to encrypt the text.

The expected output should be: CIPHER_

import java.util.Arrays;

public class Test {

public static void main (String [] a) {  
String bellasoStr = "CIPHER_IS_LONGER_THAN_THE_PLAIN_TEXT";//key
String plainText = "TESTING";//String


int x = plainText.length();
int y = bellasoStr.length();
String bellasoEncrypted = "";


char[] chars1 = bellasoStr.toCharArray();


if (!bellasoStr.equals(plainText)) {
    for (int i = 0; i < plainText.length(); i++) {
        bellasoStr = bellasoStr.substring(0, bellasoStr.length() - i);

    }
    System.out.println(bellasoStr);
}

Answer 1

Use the following statement in a controlled way

bellasoStr = bellasoStr.substring(0, bellasoStr.length() - i);

ie

if(bellasoStr.length() <= plainText.length()) {
    bellasoStr = bellasoStr.substring(0,  bellasoStr.length() - i);
}