SpringMVC3.2 与 Freemarker 整合小记

<?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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
    
    <!-- Enables the Spring MVC @Controller programming model -->
    <mvc:annotation-driven/>
    <context:component-scan base-package="com.liuyu.learn.freemarker.controller" />
    <bean id="freemarkerConfigurer" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer" >
        <property name="configuration" ref="freemarkerConfiguration" />
    </bean>
    
    <bean id="freemarkerConfiguration" class="org.springframework.ui.freemarker.FreeMarkerConfigurationFactoryBean">
        <property name="templateLoaderPaths">
            <list>
                <value>/WEB-INF/ftl</value>
            </list>
        </property>
        <!-- 配置文件,全局设置 -->
        <property name="configLocation">
            <value>classpath:freemarker.properties</value>
        </property>
        <!-- 全局变量 -->
        <property name="freemarkerVariables">
            <map>
                <entry key="base" value="@{base}" />
                <entry key="resRoot" value="@{resRoot}" />
                <entry key="versionNo" value="@{appVersion}" />
                <entry key="buildNo" value="@{buildNo}" />
            </map>
        </property>
        <property name="defaultEncoding" value="utf-8" />
    </bean>
    
    <bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
        <property name="cache" value="false" />
        <property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView"/>
        <property name="viewNames">
            <array>
                <value>*.ftl</value>
            </array>
        </property>
        <!--  Note :  配置了 "viewNames"后一定不要配置 suffix=.ftl ,原因见下述 
        <property name="prefix" value=""/>
        <property name="suffix" value=".ftl"/> --!>
        <property name="contentType" value="text/html;charset=UTF-8"></property>
        <property name="requestContextAttribute" value="request" />
        <property name="exposeSpringMacroHelpers" value="true" />
        <property name="exposeRequestAttributes" value="true" />
        <property name="exposeSessionAttributes" value="true" />
    </bean>
</beans>

---

备注: 

1) "viewNames" 与 "suffix" 尽量不要同时配置 UrlBasedViewResolver#createView时会判断 viewName是否匹配配置的viewNames,代码段如下:

protected boolean canHandle(String viewName, Locale locale) {
        String[] viewNames = getViewNames();
        return (viewNames == null || PatternMatchUtils.simpleMatch(viewNames, viewName));
}

    在配置suffix的情况下,Controller 返回modelAndView时代码通常如下:

return "index";  // 非"index.ftl"

    此时, canHandle方法将验证不能过,导致无法找到相应的View.

 

   按上面的配置文件配置时,Controller 返回modelAndView时代码通常如下:

return "index.ftl";  // 非"index"

2) 在配置多个 viewResolver  时, 尽量配置viewNames,即按上述代码,以免导致 多个view重叠时,按order来加载view的情况,并会引申问题 3)

 

3) Spring 视图判断问题:  AbstractUrlBasedView#checkResource 判断view对应的资源是否存在时, 代码如下: 

public boolean checkResource(Locale locale) throws Exception {
    return true;
}

     很显然,在配置多个viewResolver  时,一定会出问题..即  有 a.ftl 文件 , 但 jsp viewResolver  order更高,即使你是想让Spring匹配a.ftl,但它在匹配viewResolver  时,就已经假设该资源&View一定存在,但 Dispatcher.render view时,就会报错.