WEB-INF/appServlet/servlet-context.xml에 해당 부분 넣어주기.

<beans:bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
		<beans:property name="basenames">
			<beans:list>
				<beans:value>error_message</beans:value> **<!-- /src/main/resources/error_message.properties -->**
			</beans:list>
		</beans:property>
		<beans:property name="defaultEncoding" value="UTF-8"/>
	</beans:bean>

validator 인터페이스를 구현하는 객체validator 클래스를 만듦.

ex)UserValidator

public class UserValidator implements Validator {

									...
									
}