spring中父子容器

在spring容器中,分有父容器和子容器

父容器是使用了ContextLoaderListener加载并实例化的ioc容器为父容器

子容器是使用了DispatcherServerlet加载并实例化的ioc容器为子容器

他们之间的关系是

父容器不能调用子容器中任何的组件,子容器可以调用除了controller以外的组件.

列如父容器要调用子容器中dubbo的服务,这时是无法调用的,会出现空指针异常,只能通过父容器再实例化一次dubbo才能调用.

DispatcherServlet内实例化dubbo容器为子容器,如下

<servlet>
   <servlet-name>springmvc</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <!--  指定加载的配置文件 ，通过参数 contextConfigLocation 加载 -->
   <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring/springmvc.xml</param-value>
   </init-param>
   <load-on-startup>1</load-on-startup>
</servlet>

ContextLoaderListener内实例化security容器为父容器,如下
<listener>
   <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>classpath:spring/spring-*.xml</param-value>
</context-param>

下面是springmvc.xml配置文件

<?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:dubbo="http://code.alibabatech.com/schema/dubbo"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean
                    class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                <property name="supportedMediaTypes" value="application/json"/>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>
    <context:component-scan base-package="cn.ryq.shop.controller"/>
    <!--  引用 dubbo  服务  -->
    <dubbo:application name="pinyougou-shop-web">
        <!--  不开启 qos ； qos 可通过指令动态调动提供的服务  -->
        <dubbo:parameter key="qos.enable" value="false"/>
    </dubbo:application>
    <dubbo:registry address="zookeeper://192.168.12.168:2181"/>
    <dubbo:annotation package="cn.ryq.shop.controller" />
</beans>

下面是security.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security"
             xmlns:beans="http://www.springframework.org/schema/beans"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
             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.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <!--  引用 dubbo  服务  -->
    <dubbo:application name="pinyougou-shop-web" >
        <!--  不开启 qos ； qos 可通过指令动态调动提供的服务  -->
        <dubbo:parameter key="qos.enable" value="false"/>
    </dubbo:application>
    <dubbo:registry address="zookeeper://192.168.12.168:2181"/>
    <dubbo:annotation package="cn.ryq.shop.service.impl" />
    <http pattern="/shoplogin.html" security="none"/>
    <http pattern="/register.html" security="none"/>
    <http pattern="/seller/add.do" security="none"/>
    <http pattern="/js/**" security="none"/>
    <http pattern="/css/**" security="none"/>
    <http pattern="/img/**" security="none"/>
    <http pattern="/plugins/**" security="none"/>
    <http use-expressions="false">
        <intercept-url pattern="/**" access="ROLE_SELLER"/>
        <form-login login-page="/shoplogin.html" authentication-success-forward-url="/admin/index.html"
                    authentication-failure-forward-url="/shoplogin.html" always-use-default-target="true"/>
        <csrf disabled="true"/>
        <headers>
            <frame-options policy="SAMEORIGIN"/>
        </headers>
        <logout/>
    </http>
    <beans:bean class="org.springframework.security.crypto.password.NoOpPasswordEncoder" id="passwordEncoder"/>
    <beans:bean class="cn.ryq.shop.service.impl.UserDetailsServiceImpl" id="userDetailsService"/>
    <authentication-manager>
        <authentication-provider user-service-ref="userDetailsService">
            <password-encoder ref="passwordEncoder"/>
        </authentication-provider>
    </authentication-manager>
</beans:beans>

下面是父容器要调用子容器中的组件,dubbo的服务对象

public class UserDetailsServiceImpl implements UserDetailsService {
    @Reference(timeout = 3000)
    private SellerService sellerService;