How to check if two words are anagrams

Question

I have a program that shows you whether two words are anagrams of one another. There are a few examples that will not work properly and I would appreciate any help, although if it were not advanced that would be great, as I am a 1st year programmer. "schoolmaster" and "theclassroom" are anagrams of one another, however when I change "theclassroom" to "theclafsroom" it still says they are anagrams, what am I doing wrong?

import java.util.ArrayList;
public class AnagramCheck {
    public static void main(String args[]) {
        String phrase1 = "tbeclassroom";
        phrase1 = (phrase1.toLowerCase()).trim();
        char[] phrase1Arr = phrase1.toCharArray();

        String phrase2 = "schoolmaster";
        phrase2 = (phrase2.toLowerCase()).trim();
        ArrayList<Character> phrase2ArrList = convertStringToArraylist(phrase2);

        if (phrase1.length() != phrase2.length()) {
            System.out.print("There is no anagram present.");
        } else {
            boolean isFound = true;
            for (int i = 0; i < phrase1Arr.length; i++) {
                for (int j = 0; j < phrase2ArrList.size(); j++) {
                    if (phrase1Arr[i] == phrase2ArrList.get(j)) {
                        System.out.print("There is a common element.\n");
                        isFound =;
                        phrase2ArrList.remove(j);
                    }
                }
                if (isFound == false) {
                    System.out.print("There are no anagrams present.");
                    return;
                }
            }
            System.out.printf("%s is an anagram of %s", phrase1, phrase2);
        }
    }

    public static ArrayList<Character> convertStringToArraylist(String str) {
        ArrayList<Character> charList = new ArrayList<Character>();
        for (int i = 0; i < str.length(); i++) {
            charList.add(str.charAt(i));
        }
        return charList;
    }
}

Answer 1

Fastest algorithm would be to map each of the 26 English characters to a unique prime number. Then calculate the product of the string. By the fundamental theorem of arithmetic, 2 strings are anagrams if and only if their products are the same.