Password Validation Regex

PasswordValidationTest.java

public class PasswordValidationTest {

    private Pattern pattern;

    @Before
    public void setUp() {
        String regex = "^(((?=.*[a-z])(?=.*[A-Z])(?=.*\\d))|((?=.*[A-Z])(?=.*\\d)(?=.*[@$!%*#?&]))|((?=.*[a-z])(?=.*[A-Z])(?=.*[@$!%*#?&]))|((?=.*[a-z])(?=.*\\d)(?=.*[@$!%*#?&])))(?=\\S+$).{8,}$";
        pattern = Pattern.compile(regex);
    }

    @Test
    public void test_first_valid_password_example() {
        //Number, upper case, lower case in no particular order
        String password = "13Edlpouhgfdcfvgbqb";
        Assert.assertTrue(matchPassword(password));
    }

    @Test
    public void test_second_valid_password_example() {
        //Lower case, number, special character in no particular order
        String password = "dfgjrwerdvfbghjhgfdxc90@";
        Assert.assertTrue(matchPassword(password));
    }

    @Test
    public void test_third_valid_password_example() {
        //Upper case, number, lower case in no particular order
        String password = "POIIUHGFBGNHUYF2df";
        Assert.assertTrue(matchPassword(password));
    }

    @Test
    public void test_fourth_valid_password_example() {
        //Upper case, lower case, number, special character in no particular order
        String password = "KJSrtyhgh!58E543561#";
        Assert.assertTrue(matchPassword(password));
    }

    @Test
    public void test_invalid_password_example() {
        String password = "TGsayhtgfdcsxrbfdvc";
        Assert.assertFalse(matchPassword(password));
    }

    //Utility function
    private boolean matchPassword(String password) {
        Matcher matcher = pattern.matcher(password);
        return matcher.matches();
    }
}