use spring in vaadin

问题:

i want to use spring in vaadin
it's my config:
web.xml

<context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>VaadinApplicationServlet</servlet-name>
        <servlet-class>com.vaadin.server.VaadinServlet</servlet-class>
        <init-param>
            <param-name>UI</param-name>
            <param-value>com.MyUI</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>VaadinApplicationServlet</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

applicationContext.xml
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="org.postgresql.Driver"/>
        <property name="url" value="jdbc:postgresql://localhost:5432/Activiti"/>
        <property name="username" value="postgres"/>
        <property name="password" value="10"/>
    </bean>

    <bean id="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
        <property name="databaseType" value="postgres"/>
        <property name="dataSource" ref="dataSource"/>
        <property name="transactionManager" ref="transactionManager"/>
        <property name="databaseSchemaUpdate" value="true"/>
        <property name="deploymentResources"
                  value="classpath* : #{Init.path_Process}"/>
        <property name="history" value="audit"/>
        <property name="jobExecutorActivate" value="false"/>
    </bean>

    <bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
        <property name="processEngineConfiguration" ref="processEngineConfiguration"/>
    </bean>

    <bean id="repositoryService" factory-bean="processEngine"
          factory-method="getRepositoryService"/>
    <bean id="runtimeService" factory-bean="processEngine"
          factory-method="getRuntimeService"/>
    <bean id="taskService" factory-bean="processEngine"
          factory-method="getTaskService"/>
    <bean id="historyService" factory-bean="processEngine"
          factory-method="getHistoryService"/>
    <bean id="managementService" factory-bean="processEngine"
          factory-method="getManagementService"/>
    <bean id="formService" factory-bean="processEngine"
          factory-method="getFormService"/>
    <bean id="identityService" factory-bean="processEngine"
          factory-method="getIdentityService"/>

    <bean id="Init" class="util.Init"/>
    <context:annotation-config/>
    <context:component-scan base-package="com"/>    
    <context:spring-configured/>
    <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
    <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor"/>

in MyUI class:
#java
@Component
@Configurable
public class MyUI extends UI {
 protected void init(VaadinRequest vaadinRequest) {
...
@Autowired
    private IdentityService identityService;
...
}}

this config work in junit and Ok!
but
when run in vaadin and tomcat , java.lang.NullPointerException error for identityService
where is my problem?
thanks

回答1:

com.MyUI is created by the Vaadin servlet and that servlet does not know about Spring. What's happening is that your UI instance is created by reflection and isn't a Spring managed bean.

You need to use a Vaadin plugin that integrates with Spring. Please check the vaadin4spring project for more details.

Maybe you should update the class to org.vaadin.spring.servlet.SpringAwareVaadinServlet?

回答2:

Try to autowire your bean explicite (e.g. in the constructor):

   if (VaadinServlet.getCurrent() != null) {
        try {
            WebApplicationContextUtils
                    .getRequiredWebApplicationContext(VaadinServlet.getCurrent().getServletContext())
                    .getAutowireCapableBeanFactory().autowireBean(this);
        } catch (BeansException e) {
            LOG.error("Could not inject beans!" + this.getClass(), e); //$NON-NLS-1$
        }
    }

回答3:

You may use ru.xpoft.vaadin.SpringVaadinServlet, check Vaadin website-addons

<servlet>
    <servlet-name>MyCustom Application</servlet-name>
      <servlet-class>ru.xpoft.vaadin.SpringVaadinServlet</servlet-class> ...............