Java SpringMVC SAML库引发IllegalArgumentException:“；未找到名为MetadataKeyInfoGenerator的管理器"；生成服务元数据时

我试图在JavaSpringMVC框架内设置SAML。 基本上每当我尝试访问任一服务提供商（

http://baseaddress/context/saml/metadata

）或触发单点登录（应重定向到身份提供程序）我得到异常：

java.lang.IllegalArgumentException:名为“MetadataKeyInfoGenerator”的管理器不存在

。如果我使用

ResourceBackedMetadataProvider

，它就可以工作

<!-- IDP Metadata configuration - paths to metadata of IDPs in circle of trust is here -->
<bean id="metadata" class="org.springframework.security.saml.metadata.CachingMetadataManager">
    <constructor-arg>
        <list>      
            <bean class="org.springframework.security.saml.metadata.ExtendedMetadataDelegate">
                <property name="metadataTrustCheck" value="false" />
                <property name="metadataRequireSignature" value ="false" />
                <constructor-arg>
                    <bean class="org.opensaml.saml2.metadata.provider.HTTPMetadataProvider">
                        <constructor-arg>
                            <value type="java.lang.String">http://localhost:8088/metadata</value>
                        </constructor-arg>
                        <constructor-arg>
                            <value type="int">15000</value>
                        </constructor-arg>
                        <property name="parserPool" ref="parserPool"/>
                    </bean>
                </constructor-arg>
                    <constructor-arg>
                        <bean class="org.springframework.security.saml.metadata.ExtendedMetadata"/>
                    </constructor-arg>
            </bean> 
        </list>
    </constructor-arg>
    <!-- OPTIONAL used when one of the metadata files contains information about this service provider -->
    <!-- <property name="hostedSPName" value=""/> -->
    <!-- OPTIONAL property: can tell the system which IDP should be used for authenticating user by default. -->
    <!-- <property name="defaultIDP" value="http://localhost:8080/opensso"/> -->
</bean>

http://localhost:8088/metadata
15000