Spring MVC Service Beans loaded twice

Question

I have a problem with my Spring MVC application where my @Service classes are being created twice. I found few threads discussing this issue and most of the time it's related to have the <context:component-scan /> defined both in the Application and also Servlet Context. But in my case I have all the configuration in the Application Context file and the Servlet Context conf file is empty. I'm including the web.xml and the applicationContext.xml files.

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>

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

If you use spring mvc. There will be two context in your application. the spring context which is based on applicationContext.xml and the appServlet-servlet.xml(the name is based on your servlet name appServlet).

When the spring context init, it will component-scan your package defined in applicationContext.xml. It is the first time your service created. Then when you use DispatcherServlet, it will create a spring context. If you have appServlet-servlet.xml, it is based on this. if else, it will component-scan all your classpath. It is the second time your service created.

If you don't want it, you can write it in your applicationContext.xml:

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

And then you should create appServlet-servlet.xml and write component-scan like this:

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

So you can hold all your compontent and service in your spring context. And spring mvc will just hold the controller.