Spring-MVC：创建良好的基础架构（配置）并避免重复

您的代码和配置可以改善很多方面。让我们从您的dao开始，不要将

Session

in
存储在实例变量中，我强烈建议对所需的依赖项使用构造函数注入。考虑到这一点，您的dao应该看起来像这样。

@Transactional@Repositorypublic class CanvasDAOImpl implements CanvasDAO{    private final SessionFactory sessionFactory;    @Autowired    public CanvasDAOImpl(SessionFactory sessionFactory) {        this.sessionFactory=sessionFactory;    }   @overrride   public returnType methodName(params..){        Session session = this.sessionFactory.getCurrentSession();        // Do stuff with the session.    }}

No more setters (especially not for the

Session

!) just a plain class. The
same applies for the

@Service

classes.

@Service@Transactionalpublic class CanvasServiceImpl implements CanvasService {    private final CanvasDAO canvasDAO;    public CanvasServiceImpl(CanvasDAO canvasDAO) {        this.canvasDAO=canvasDAO;    }    //methods}

In your configuration you have explicitly defined all your

@Repository

and

@Service

beans. You also have a

<context:component-scan />

which already
detects all

@Component

s. Remove all explicitly declared

@Repository

and

@Service

beans. This will really clean up your configuration!.

In your hibernate configuration the

c3p0

and

connection

properties are
useless as you are injecting a

DataSource

and hibernate is’t managing it but
Spring is. Remove those lines. Also to cleanup this configuration further
instead of specifying each and every class it needs to proces add

packagesToScan

so it will automatically detect

@Entity

annotated beans.

<context:annotation-config />

is already implied by the use of

<context:component-scan />

so you can remove it as it basically duplicates
things.

You have explicitly defined a

RequestMappingHandlerMapping

which doesn’t do
anything as there is already one registered by

<mvc:annotation-driven />

. It
only takes up memory, the

MappingJackson2HttpMessageConverter

is registered
automatically of Jackson2 is detected on the class path so no need to do that.

Chancing the

Locale

doesn’t work for all URLs as you forgot to register the
interceptor with the

<mvc:annotation-driven />

element.

When applying all that advice to your classes and configuration the remaining
configuration looks like this.

    <context:component-scan base-package="com.journaldev.spring"/>    <context:property-placeholder location="classpath:application.properties"/>    <mvc:annotation-driven>        <mvc:argument-resolvers> <beans:bean />        </mvc:argument-resolvers>    </mvc:annotation-driven>    <mvc:interceptors>        <beans:bean />        <beans:ref bean="localeChangeInterceptor" />    </mvc:interceptors>    <mvc:default-servlet-handler/>    <resources mapping="/resources/" location="/resources/"/>    <beans:bean >        <beans:property name="prefix" value="/WEB-INF/views/"/>        <beans:property name="suffix" value=".jsp"/>    </beans:bean>    <beans:bean id="dataSource"      destroy-method="close">        <beans:property name="driverClassName" value="org.postgresql.Driver"/>        <beans:property name="url"  value="jdbc:postgresql://localhost:5432/dbname"/>        <beans:property name="username" value="dbuser"/>        <beans:property name="password" value="dbpass"/>        <beans:property name="removeAbandoned" value="true"/>        <beans:property name="removeAbandonedTimeout" value="20"/>        <beans:property name="defaultAutoCommit" value="false"/>    </beans:bean>    <!-- Hibernate 4 SessionFactory Bean definition -->    <beans:bean id="hibernate4AnnotatedSessionFactory" >        <beans:property name="dataSource" ref="dataSource"/>        <beans:property name="packagesToScan" value="com.journaldev.spring.model" />    </beans:property>        <beans:property name="hibernateProperties"> <beans:props>     <beans:prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQL9Dialect</beans:prop>     <beans:prop key="hibernate.show_sql">false</beans:prop>  <!--   <beans:prop key="hibernate.jdbc.batch_size">1000</beans:prop>     <beans:prop key="hibernate.order_updates">true</beans:prop>-->     <beans:prop key="hibernate.hbm2ddl.auto">update</beans:prop> </beans:props>        </beans:property>    </beans:bean>    <task:annotation-driven/>    <tx:annotation-driven transaction-manager="transactionManager"/>    <beans:bean id="transactionManager" >        <beans:property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory"/>    </beans:bean>    <!--  <beans:bean id="bayeux"  init-method="start" destroy-method="stop">          <beans:property name="transports">   <beans:list>       <beans:bean id="jsonTransport" ><beans:constructor-arg ref="bayeux"/>       </beans:bean>       <beans:bean id="jsonpTransport" ><beans:constructor-arg ref="bayeux"/>       </beans:bean>   </beans:list>        </beans:property>      </beans:bean>-->    <!-- locale -->    <beans:bean id="messageSource" >        <beans:property name="basename" value="classpath:/locale/messages"/>        <beans:property name="defaultEncoding" value="UTF-8"/>    </beans:bean>    <!-- default locale -->    <beans:bean id="localeResolver" >        <beans:property name="defaultLocale" value="de"/>    </beans:bean>    <!-- Change locale via url. -->    <beans:bean id="localeChangeInterceptor" >        <beans:property name="paramName" value="lang"/>    </beans:bean>    <beans:bean id="handlerMapping" >        <beans:property name="interceptors"> <beans:list>     <beans:ref bean="localeChangeInterceptor"/> </beans:list>        </beans:property>    </beans:bean>    <beans:bean />    <beans:bean id="multipartResolver" >        <beans:property name="maxUploadSize" value="52428800"/>    </beans:bean></beans:beans>

However you really should split things up in what is loaded by the

ContextLoaderListener

basically everything BUT

@Controller

s and what is
loaded by the

DispatcherServlet

just

@Controller

s and web related beans.

So the

servlet-context.xml

should look something like this.

    <context:component-scan base-package="com.journaldev.spring" use-default-filters="false">        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />    </context:component-scan>    <context:property-placeholder location="classpath:application.properties"/>    <mvc:annotation-driven>        <mvc:argument-resolvers> <beans:bean />        </mvc:argument-resolvers>    </mvc:annotation-driven>    <mvc:interceptors>        <beans:bean />        <beans:ref bean="localeChangeInterceptor" />    </mvc:interceptors>    <mvc:default-servlet-handler/>    <resources mapping="/resources/" location="/resources/"/>    <beans:bean >        <beans:property name="prefix" value="/WEB-INF/views/"/>        <beans:property name="suffix" value=".jsp"/>    </beans:bean>    <!-- locale -->    <beans:bean id="messageSource" >        <beans:property name="basename" value="classpath:/locale/messages"/>        <beans:property name="defaultEncoding" value="UTF-8"/>    </beans:bean>    <!-- default locale -->    <beans:bean id="localeResolver" >        <beans:property name="defaultLocale" value="de"/>    </beans:bean>    <!-- Change locale via url. -->    <beans:bean id="localeChangeInterceptor" >        <beans:property name="paramName" value="lang"/>    </beans:bean>    <beans:bean id="handlerMapping" >        <beans:property name="interceptors"> <beans:list>     <beans:ref bean="localeChangeInterceptor"/> </beans:list>        </beans:property>    </beans:bean>    <beans:bean />    <beans:bean id="multipartResolver" >        <beans:property name="maxUploadSize" value="52428800"/>    </beans:bean>

Then add what was removed and a

<context:component-scan />

(or modify it) to
the

root-context.xml

.

<context:component-scan base-package="com.journaldev.spring">    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" /></context:component-scan><context:property-placeholder location="classpath:application.properties"/><beans:bean id="dataSource"  destroy-method="close">    <beans:property name="driverClassName" value="org.postgresql.Driver"/>    <beans:property name="url"         value="jdbc:postgresql://localhost:5432/dbname"/>    <beans:property name="username" value="dbuser"/>    <beans:property name="password" value="dbpass"/>    <beans:property name="removeAbandoned" value="true"/>    <beans:property name="removeAbandonedTimeout" value="20"/>    <beans:property name="defaultAutoCommit" value="false"/></beans:bean><!-- Hibernate 4 SessionFactory Bean definition --><beans:bean id="hibernate4AnnotatedSessionFactory" >    <beans:property name="dataSource" ref="dataSource"/>    <beans:property name="packagesToScan" value="com.journaldev.spring.model" /></beans:property>    <beans:property name="hibernateProperties">        <beans:props> <beans:prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQL9Dialect</beans:prop> <beans:prop key="hibernate.show_sql">false</beans:prop>         <!--   <beans:prop key="hibernate.jdbc.batch_size">1000</beans:prop> <beans:prop key="hibernate.order_updates">true</beans:prop>--> <beans:prop key="hibernate.hbm2ddl.auto">update</beans:prop>        </beans:props>    </beans:property></beans:bean><task:annotation-driven/><tx:annotation-driven transaction-manager="transactionManager"/><beans:bean id="transactionManager" >    <beans:property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory"/></beans:bean><!--  <beans:bean id="bayeux"  init-method="start" destroy-method="stop">      <beans:property name="transports">          <beans:list>   <beans:bean id="jsonTransport" >       <beans:constructor-arg ref="bayeux"/>   </beans:bean>   <beans:bean id="jsonpTransport" >       <beans:constructor-arg ref="bayeux"/>   </beans:bean>          </beans:list>    </beans:property>  </beans:bean>-->

Remove the

<import resource="servlet-context.xml" />

from your

security-context.xml

.

Finally let the

DispatcherServlet

load the

servlet-context.xml

instead of
the

security-context.xml

.

Now as you aren’t loading beans twice per context anymore you should have a
reduced memory footprint and you shouldn’t have 4 scheduled jobs any more.
Also your

Email

class should, ideally, also be a Spring managed bean and I
would suggest using the

JavaMailSender

API which simplifies sending emails.

So basically the task ahead for you is to mainly remove things, you will end
up with less pre and less configuration and still achieve the same.

For more hands-on-advice I’m for hire ;)…