mvc:resources does not work for Spring

The error message is as follows

cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'mvc:resources'.

The problem is often caused by improper setting in yourproject-servlet.xml file.  

The validated xxx-servlet.xml is as follows.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:util="http://www.springframework.org/schema/util" xmlns:context="http://www.springframework.org/schema/context"
       xmlns:oxm="http://www.springframework.org/schema/oxm"
       xsi:schemaLocation="http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.0.xsd
  http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
  http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
  http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd
  http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
      
    <context:component-scan base-package="com.xxx.controller" /> 
    
    <mvc:resources mapping="/resources/**" location="/resources/" />
    <!-- also add the following beans to get rid of some exceptions -->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
    <bean
        class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
    </bean>
    
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/WEB-INF/pages/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>
    
</beans>