[CHALLENGE]: String rotation

challenge-string-rotation.txt

- Write a func that accepts 2 strings, and returns true if one string is rotation of the other:
"abcde", "eabcd" - true
"abcde", "cdeab" - true
"abcde", "abced" - false
"abc",   "a"     - false

StringRotationCompactCode.java

import org.junit.Test;

public class StringRotationCompactCode {
    @Test
    public void test() {
        System.err.println("abcde => eabcd: " + isRotation("abcde", "eabcd"));
        System.err.println("abcde => cdeab: " + isRotation("abcde", "cdeab"));
        System.err.println("abcde => abced: " + isRotation("abcde", "abced"));
        System.err.println("abc => a: " + isRotation("abc", "a"));
    }

    private boolean isRotation(String str1, String str2) {
        if (str1.length() != str2.length()) return false;
        String str1Repeated = str1.concat(str1).concat(str1);
        return str1Repeated.contains(str2);
    }
}

StringRotationMassiveCode.java

import org.junit.Test;

public class StringRotationMassiveCode {
    @Test
    public void test() {
        System.err.println("abcde => eabcd: " + isRotation("abcde", "eabcd"));
        System.err.println("abcde => cdeab: " + isRotation("abcde", "cdeab"));
        System.err.println("abcde => abced: " + isRotation("abcde", "abced"));
        System.err.println("abc => a: " + isRotation("abc", "a"));
    }

    private boolean isRotation(String str1, String str2) {
        if (str1.length() != str2.length()) return false;

        String str2Copy = str2;

        for (int x = 1; x <= str1.length(); x++) {
            char firstChar = str2Copy.charAt(0);
            str2Copy = str2Copy.substring(1, str2.length()) + firstChar;

            if (str2Copy.equals(str1)) return true;
        }

        return false;
    }
}