Exemplo configuração i18n spring.

mvc-dispatcher-servlet

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

	<bean id="localeResolver"
		class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
		<property name="defaultLocale" value="en" />
	</bean>

	<bean id="localeChangeInterceptor"
		class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
		<property name="paramName" value="language" />
	</bean>
	
	<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" >
		<property name="interceptors">
			<list>
				<ref bean="localeChangeInterceptor" />
			</list>
		</property>
	</bean>

	<!-- Register the welcome.properties -->
	<bean id="messageSource"
		class="org.springframework.context.support.ResourceBundleMessageSource">
		<property name="basename" value="welcome" />
	</bean>

</beans>