added PasswordValidator and exception methods

src/main/java/core/basesyntax/PasswordValidationException.java

@@ -4,4 +4,5 @@ public class PasswordValidationException extends Exception {
     public PasswordValidationException(String message) {
         super(message);
     }
+
 }

src/main/java/core/basesyntax/PasswordValidator.java

@@ -1,12 +1,12 @@
 package core.basesyntax;
 
 public class PasswordValidator {
-    public static final int MIN_VALUE_FOR_PASSWORD = 10;
+    public static final int MIN_PASSWORD_LENGTH = 10;
 
     public void validate(String password, String repeatPassword)
             throws PasswordValidationException {
-        if (password != repeatPassword || password.length() < MIN_VALUE_FOR_PASSWORD
-                || password == null || repeatPassword == null) {
+        if (password == null || repeatPassword == null
+                || !password.equals(repeatPassword) || password.length() < MIN_PASSWORD_LENGTH) {
             throw new PasswordValidationException("Wrong passwords");
         }
     }

src/main/java/core/basesyntax/UserService.java

@@ -3,7 +3,7 @@
 public class UserService {
     private PasswordValidator passwordValidator = new PasswordValidator();
 
-    public void registerUser(User user) throws PasswordValidationException {
+    public void registerUser(User user) {
         try {
             passwordValidator.validate(user.getPassword(), user.getRepeatPassword());
             saveUser(user);