[Feature] email validation

giftrio/src/main/java/com/fluffytrio/giftrio/utils/validation/Validation.java

@@ -0,0 +1,14 @@
+package com.fluffytrio.giftrio.utils.validation;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class Validation {
+
+    public boolean isValidEmail(String email){
+        String emailRegex = "^[_a-z0-9-]+(.[_a-z0-9-]+)*@(?:\\w+\\.)+\\w+$";
+        Pattern pattern = Pattern.compile(emailRegex);
+        Matcher matcher = pattern.matcher(email);
+        return matcher.matches();
+    }
+}

giftrio/src/test/java/com/fluffytrio/giftrio/utils/validation/ValidationTest.java

@@ -0,0 +1,22 @@
+package com.fluffytrio.giftrio.utils.validation;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(SpringRunner.class)
+public class ValidationTest {
+
+    Validation validation = new Validation();
+
+    @Test
+    public void emailValidationTest() {
+        String notValidEmail = "email";
+        String validEmail = "email@test.com";
+
+        assertThat(validation.isValidEmail(notValidEmail)).isFalse();
+        assertThat(validation.isValidEmail(validEmail)).isTrue();
+    }
+}