配置Spring-Security报错，找不到元素 'b:beans' 的声明

Spring新手，现在想在SpringMVC的基础上使用Spring Security框架。但Spring Security配置报错，困扰了很久。先上代码

 <?xml version="1.0" encoding="UTF-8"?>

<b:beans xmlns="http://www.springframework.org/schema/security" 
        xmlns:b="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.xsd
                            http://www.springframework.org/schema/security 
                            http://www.springframework.org/schema/security/spring-security-3.1.xsd">

报错

 org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 9 in XML document from class path resource [config/spring-security.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 9; columnNumber: 99; cvc-elt.1: 找不到元素 'b:beans' 的声明。

尝试网上的方法，加入

 <!DOCTYPE b:beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

则报错

 org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 9 in XML document from class path resource [config/spring-security.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 9; columnNumber: 99; 必须声明元素类型 "b:beans"。

请指教

<?xml version="1.0" encoding="UTF-8"?>
xmlns:security="http://www.springframework.org/schema/security"
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-3.1.xsd
http://www.springframework.org/schema/security
http://www.springframework.org/schema/security/spring-security-3.1.xsd">

<security:http auto-config='true'>

<curity:http>
<security:http auto-config="true" use-expressions="false" 
    access-denied-page="/login.jsp">

    <security:form-login login-page="/login.jsp"
        authentication-failure-url="/login.jsp?error=true"
        authentication-success-handler-ref="loginSuccessHandler"
        always-use-default-target="true" />
    <security:logout logout-url="/logout" logout-success-url="/login.jsp"/>
    <security:session-management>
        <security:concurrency-control
            max-sessions="1" error-if-maximum-exceeded="false" expired-url="/login.jsp?error=islogin"><curity:concurrency-control>
    <curity:session-management>

    <security:intercept-url pattern="rvices/**"
        access="IS_AUTHENTICATED_FULLY"><curity:intercept-url>
    <security:intercept-url pattern="/jsp/*.jsp"
        access="IS_AUTHENTICATED_FULLY"><curity:intercept-url>
    <security:custom-filter ref="myFilter"
        before="FILTER_SECURITY_INTERCEPTOR" />

<curity:http>

<security:authentication-manager alias="authenticationManager">
    <security:authentication-provider
        user-service-ref="myUserDetailService">
    <curity:authentication-provider>
<curity:authentication-manager>

<bean id="loginSuccessHandler" class="com.springsecurity.handler.LoginSuccessHandler">
    <property name="jdbcService" ref="jdbcService" />
</bean>

<bean id="myFilter" class="com.springsecurity.filter.MyFilterSecurityInterceptor">
    <property name="authenticationManager" ref="authenticationManager" />
    <property name="accessDecisionManager" ref="myAccessDecisionManagerBean" />
    <property name="securityMetadataSource" ref="mySecurityMetadataSource" />
</bean>
<bean id="myUserDetailService" class="com.springsecurity.handler.MyUserDetailService">
    <property name="userDao" ref="userDao" />
    <property name="jdbcService" ref="jdbcService" />
</bean>

<bean id="myAccessDecisionManagerBean" class="com.springsecurity.filter.MyAccessDecisionManager">
    <property name="myInvocationSecurityMetadataSource" ref="mySecurityMetadataSource" />
</bean>

<bean id="mySecurityMetadataSource"
    class="com.springsecurity.filter.MyInvocationSecurityMetadataSource">
    <constructor-arg>
        <ref bean="roleDao" />
    </constructor-arg>
</bean>

改成这种即可解决。