Song Encryption - Regex, char range containing different sym

package com.company;

import javafx.util.Pair;

import javax.xml.crypto.dsig.keyinfo.KeyValue;
import java.lang.reflect.Array;
import java.security.KeyStore;
import java.text.Collator;
import java.text.DecimalFormat;
import java.util.*;
import java.util.function.Predicate;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collector;
import java.util.stream.Collectors;


public class Main {

    public static String encrypt(String artist, String song, int key){
        String cryptedArtist = "";
        String cryptedSong = "";

        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < artist.length(); i++) {
            char character = artist.charAt(i);
            if(character == '\'' | character == ' '){
                builder.append(character);
                continue;
            }
            int encryptedCharacter;
            if((int) character + key > 122){
                int tempKey = (character) + key - 122 - 1;
                encryptedCharacter = (int) 'a' + tempKey;
            }else{
                encryptedCharacter = (int) character + key;
            }
            builder.append((char) encryptedCharacter);
        }
        cryptedArtist = builder.toString();
        builder = new StringBuilder();

        for (int i = 0; i < song.length(); i++) {
            char character = song.charAt(i);
            if(character == '\'' | character == ' '){
                builder.append(character);
                continue;
            }
            int encryptedCharacter;
            if((int) character + key > 90){
                int tempKey = (character) + key - 90 - 1;
                encryptedCharacter = (int) 'a' + tempKey;
            }else{
                encryptedCharacter = (int) character + key;
            }
            String appender =(char) encryptedCharacter + "";
            builder.append(appender.toUpperCase());
        }
        cryptedSong = builder.toString();

        return cryptedArtist + "@" + cryptedSong;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        final String REGEX =  "^([A-Z][a-z' ]+):([A-Z\\s]+)$";
        Pattern pattern = Pattern.compile(REGEX);

        String input = "";
        while(!"end".equals(input = scanner.nextLine())){
            Matcher matcher = pattern.matcher(input);
            if(matcher.find()){
                String artist = matcher.group(1);
                String song = matcher.group(2);

                int key = artist.length();

                System.out.print("Successful encryption: ");
                System.out.println(encrypt(artist, song, key));
            }else{
                System.out.println("Invalid input!");
            }
        }
    }
}