SpringMVC同时支持多视图(JSP,Velocity,Freemarker等)的一种思路实现

在基于SpringMVC的项目中有时需要同时使用多种视图格式，如jsp,velocity及freemarker等，通过不同的请求路径配置规则，映射到不同的视图文件。下面我提供一种思路，通过视图模板文件后缀名的方式来进行处理。例如：

@RequestMapping(value = "/hello")
public String jspTest(HttpServletRequest request, ModelMap map) {
    return "demo.jsp";
}
将通过”demo.jsp”的后缀自动使用jsp的视图解析器。

 

下面描述下详细思路：

 

一.自定义视图解析器

package com.jeedev.common.web.springmvc.view;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.ViewResolver;

/**
 * 自定义视图解析(通过配置实现多视图整合,如jsp,velocity,freemarker,pdf,excel...)
 * @author huligong
 *
*/
public class JeeDevViewResolver implements ViewResolver  {

private static Log logger = LogFactory.getLog(JeeDevViewResolver.class);

public View resolveViewName(String viewName, Locale locale) throws Exception {
for(Map.Entry<Set<String>, ViewResolver> map : viewResolverMap.entrySet()){
           Set<String> suffixs = map.getKey();
for(String suffix : suffixs){
if (viewName.endsWith(suffix)){
                   ViewResolver viewResolver = map.getValue();
if(null != viewResolver){
if (logger.isDebugEnabled()) {
                            logger.debug("found viewResolver '" + viewResolver + "' for viewName '" + viewName+ "'");
                        }
return viewResolver.resolveViewName(viewName, locale);
                   }
               }
           }
       }

if(defaultViewResolver != null){
return defaultViewResolver.resolveViewName(viewName, locale);
       }
// to allow for ViewResolver chaining
return null;
    }


private Map<Set<String>,ViewResolver> viewResolverMap = new HashMap<Set<String>,ViewResolver>();

private ViewResolver defaultViewResolver = null;

public Map<Set<String>, ViewResolver> getViewResolverMap() {
return viewResolverMap;
    }

public void setViewResolverMap(Map<Set<String>, ViewResolver> viewResolverMap) {
this.viewResolverMap = viewResolverMap;
    }

public ViewResolver getDefaultViewResolver() {
return defaultViewResolver;
    }

public void setDefaultViewResolver(ViewResolver defaultViewResolver) {
this.defaultViewResolver = defaultViewResolver;
    }
}

在自定义视图解析器(其实是视图中转器)中，通过对视图文件的后缀判断(而不是请求地址的后缀)而返回给不同的视图解析器处理。

 

二.视图映射配置dispather-servlet.xml

 

<bean id="viewResolver" class="com.jeedev.common.web.springmvc.view.JeeDevViewResolver">
<property name="defaultViewResolver" ref="beanNameViewResolver"/>
<property name="viewResolverMap">
<map>
<entry>
<key>
<set>
<value>.jsp</value>
</set>
</key>
<ref bean="jspViewResolver"/>
</entry>
<entry>
<key>
<set>
<value>.vm</value>
<value>.htm</value>
</set>
</key>
<ref bean="velocityViewResolver"/>
</entry>
<entry>
<key><value>.ftl</value></key>
<ref bean="freeMarkerViewResolver"/>
</entry>
</map>
</property>
</bean>


<bean id="beanNameViewResolver" class="org.springframework.web.servlet.view.BeanNameViewResolver"/>

<bean id="jspViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsp/"/>
<!--<property name="suffix" value=".jsp"/>-->
</bean>

<!--  Velocity ViewResolver Configuration -->
<bean id="velocityViewResolver" class = "org.springframework.web.servlet.view.velocity.VelocityViewResolver">
<property name="order" value="0" />
<property name="contentType" value="text/html;charset=UTF-8" />
<property name="requestContextAttribute" value="req"/>
</bean>

<!-- Velocity Configuration -->     
<bean id="velocityConfig" class = "org.springframework.web.servlet.view.velocity.VelocityConfigurer">
<property name="configLocation" value="/WEB-INF/velocity.properties"/>
<property name="resourceLoaderPath" value="/" />
</bean>

<!--  FreeMarker ViewResolver Configuration -->
<bean id="freeMarkerViewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">  
<property name="order" value="0" />
<property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView"/>  
</bean> 


<!-- FreeMarker Configuration -->     
<bean id="freemarkerConfig"  class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">  
<property name="configLocation" value="/WEB-INF/freemarker.properties"/>
<property name="templateLoaderPath" value="/WEB-INF/ftl/"/>  
<property name="freemarkerVariables">
<map>
<entry key="xml_escape" value-ref="fmXmlEscape"/>
</map>
</property>
</bean>   

<bean id="fmXmlEscape" class="freemarker.template.utility.XmlEscape"/>

这里我配置成所有返回.jsp的视图模板请求都转到JSP视图解析器jspViewResolver中去处理，返回.htm,.vm视图模板请求都转到velocity视图解析器中去处理。

 

三.控制器代码示例

 

package com.jeedev.demo.view;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 多视图解析器支持示例
 * @author huligong
 *
*/
@Controller
@RequestMapping(value = "/demo")
public class JeeDevViewResolverTestController {
private static Log logger = LogFactory.getLog(JeeDevViewResolverTestController.class);

    @RequestMapping(value = "/test1")
public String test1(HttpServletRequest request, ModelMap map) {
        logger.info("使用JSP视图解析器");
        map.put("name", "hello world");
return "jspTest.jsp";
    }

    @RequestMapping(value = "/test2")
public String test2(HttpServletRequest request, ModelMap map) {
        logger.info("使用Freemarker视图解析器");
        map.put("name", "hello world");
return "hello.ftl";
    }

    @RequestMapping(value = "/test3")
public String test3(HttpServletRequest request, ModelMap map) {
        logger.info("使用Velocity视图解析器");
        map.put("name", "hello world");
return "/html/demo.htm";
    }
}

 

四.测试请求

我在web.xml里给DispatcherServlet添加了/view/*，所以，只要在请求前加上/view就可以了。

http://localhost:8080/view/demo/test1

http://localhost:8080/view/demo/test2

http://localhost:8080/view/demo/test3

皆验证通过。