Question

我的Spring MVC应用程序出了问题，我的@Service类被创建了两次。我发现很少有线程讨论这个问题，并且大部分时间与应用程序和Servlet Context中都定义了<context:component-scan />有关。但在我的情况下，我在Application Context文件中有所有配置，并且Servlet Context conf文件为空。我包含web.xml和applicationContext.xml个文件。

的applicationContext.xml

<?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:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:task="http://www.springframework.org/schema/task"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd">

    <tx:annotation-driven />        
    <mvc:annotation-driven />
    <task:annotation-driven />
    <context:component-scan base-package="my.app" />
    <mvc:resources mapping="/resources/**" location="/resources/" />
    <mvc:resources mapping="/assets/**" location="/WEB-INF/assets/" />
    <mvc:resources mapping="/webjars/**" location="classpath:/META-INF/resources/webjars/"/>

    <bean id="templateResolver"
        class="org.thymeleaf.templateresolver.ServletContextTemplateResolver">
        <property name="prefix" value="/WEB-INF/views/" />
        <property name="suffix" value=".html" />
        <property name="characterEncoding" value="UTF-8" />
        <property name="templateMode" value="HTML5" />
        <property name="cacheable" value="false" />
    </bean>
    <bean id="templateEngine" class="org.thymeleaf.spring3.SpringTemplateEngine">
        <property name="templateResolver" ref="templateResolver" />
        <property name="additionalDialects">
        <set>
          <bean class="org.thymeleaf.extras.springsecurity3.dialect.SpringSecurityDialect"/>
        </set>
        </property>
    </bean>
    <bean class="org.thymeleaf.spring3.view.ThymeleafViewResolver">
        <property name="templateEngine" ref="templateEngine" />
        <property name="characterEncoding" value="UTF-8" />
        <property name="order" value="1" />
        <property name="viewNames" value="thymeleaf/*" />
    </bean>

      <mvc:interceptors>
        <!-- Changes the locale when a 'locale' request parameter is sent; e.g. 
        /?locale=de -->
        <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor" />
      </mvc:interceptors>
      <bean id="localeResolver" class="org.springframework.web.servlet.i18n.CookieLocaleResolver">
        <property name="cookieName" value="myCookie" />
        <property name="defaultLocale" value="sk_SK" />
      </bean>


    <import resource="spring/spring-security.xml"/>     
    <import resource="spring/data-source.xml" />
    <import resource="spring/lang-source.xml"/>
    <import resource="spring/data-properties.xml"/>
    <import resource="spring/data-managers.xml" />
</beans>

的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

    <session-config>
        <session-timeout>300</session-timeout>
    </session-config>

    <servlet>
        <servlet-name>appServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
        </init-param>
        <load-on-startup>0</load-on-startup>
    </servlet>  

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <filter>
        <filter-name>SetCharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>

    <!-- Spring Security -->
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

Answer 1

如果你使用spring mvc。您的应用程序中将有两个上下文。 spring context，它基于applicationContext.xml和appServlet-servlet.xml（名称基于你的servlet名称appServlet）。

当spring context init时，它将对applicationContext.xml中定义的包进行组件扫描。这是您的服务第一次创建。然后，当您使用DispatcherServlet时，它将创建一个spring上下文。如果您有appServlet-servlet.xml，则它基于此。如果是，它将组件扫描所有类路径。这是您的服务第二次创建。

如果您不想要它，可以在applicationContext.xml中编写它：

<context:component-scan base-package="my.app">
    <context:exclude-filter type="annotation"expression="org.springframework.stereotype.Controller" />
</context:component-scan>

然后你应该创建appServlet-servlet.xml并像这样编写组件扫描：

<context:component-scan base-package="my.app" use-default-filters="false">
    <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />
</context:component-scan>

因此，您可以在春季环境中保留所有组件和服务。而spring mvc只会握住控制器。

Spring MVC Service Beans加载了两次

1 个答案: