spring mvc 配置 velocity 模板

1、必要jar包

1.1 spring的jar包

除了必要的spring核心jar包 和 spring mvc jar包， web jar包
特別注意：還要，spring-context-support 這個jar包

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context-support</artifactId>
    <version>${spring-framework.version}</version>
</dependency>

1.2 velocity的jar包

這個jar包是必須的

<dependency>
    <groupId>org.apache.velocity</groupId>
    <artifactId>velocity</artifactId>
    <version>1.7</version>
</dependency>

有時候也要用到這個jar包

<dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-tools</artifactId>
            <version>2.0</version>
        </dependency>

2、xxx-mvc.xml配置文件增加velocity環境和velocity視圖解析器

這裏是引用spring官方文檔的

<!--
This bean sets up the Velocity environment for us based on a root path for templates.
Optionally, a properties file can be specified for more control over the Velocity
environment, but the defaults are pretty sane for file based template loading.
-->
<bean id="velocityConfig" class="org.springframework.web.servlet.view.velocity.VelocityConfigurer">
    <property name="resourceLoaderPath" value="/WEB-INF/velocity/"/>
</bean>

<!--
View resolvers can also be configured with ResourceBundles or XML files. If you need
different view resolving based on Locale, you have to use the resource bundle resolver.
-->
<bean id="viewResolver" class="org.springframework.web.servlet.view.velocity.VelocityViewResolver">
    <property name="cache" value="true"/>
    <property name="prefix" value=""/>
    <property name="suffix" value=".vm"/>
</bean>

3、查錯&問題？？？

剛開始，沒有引用spring-context-surport jar包，發生如下錯誤：

Related cause: org.springframework.beans.factory.CannotLoadBeanClassException: Error loading class [org.springframework.web.servlet.view.velocity.VelocityConfigurer] for bean with name 'velocityConfig' defined in class path resource [mvc-config.xml]: problem with class file or dependent class; nested exception is **java.lang.NoClassDefFoundError: org/springframework/ui/velocity/VelocityEngineFactory**
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
    **at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)**
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:658)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:624)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:672)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:543)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:484)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1241)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1154)

但是 org.apache.velocity 的jar包我已經導入，而且工程中 類 VelocityEngineFactory 也是存在的。
往下看錯誤內容：
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)

類 AbstractApplicationContext 是在 spring-context jar包中的
所以這個是一個抽象類，但是我查看了一下它的實現類，沒有一個是在 spring-context-support包中的

所以，從錯誤日誌中，我還是不知道， 這個報錯爲什麼要引入 spring-context-support 跟這個jar包有什麼關係？