Spring mvc可以配置多种视图，比如json、xml、ftl等等(REST内容协商)。
RESTful服务中很重要的一个特性是对于同一资源,可以有多种表述形式。
既然是协商视图，那么Spring MVC REST改如何决定采用何种方式(视图)展示内容呢？
第一种：根据http request header中的Accept
Accept: text/css,*/*;q=0.1 //返回css格式数据
Accept: application/xml //返回xml格式数据
Accept: application/json //返回json格式数据
缺点：
chrome:
Accept:application/xml,application/xhtml+xml,textml;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
firefox:
Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
IE8:
Accept:image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/x-silverlight, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, */*
用户直接通过浏览器访问，由于各个浏览器发送的Accept的不一致，将导致服务器不知要返回什么格式的数据。
第二种：根据扩展名
http://www.sxrczx.com/rest.xml //将返回xml格式数据
http://www.sxrczx.com/rest.json //将返回json格式数据
http://www.sxrczx.com/rest.htm //将返回html格式数据
缺点：
不能统一通过同一URL实现多种展示视图。
第三种：根据format参数
http://www.sxrczx.com/rest?format=xml //将返回xml格式数据
http://www.sxrczx.com/rest?format=json //将返回json格式数据
http://www.sxrczx.com/rest?format=htm //将返回html格式数据
缺点：
需要额外的传递format参数，URL变得冗余，繁琐，缺少了REST的简洁风范。
配置：web.xml,显示Spring的配置文件位置
...<!-- spring mvc --><servlet> <servlet-name>SpringMvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/config/spring/appContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet><servlet-mapping> <servlet-name>SpringMvc</servlet-name> <url-pattern>*.htm</url-pattern> <url-pattern>*.json</url-pattern> <!-- <url-pattern>*.xml</url-pattern> --></servlet-mapping>...
==========================================================================================================================
Spring配置appContext.xml(无扩展名(jsp作为视图)/json/xml)
<!-- 根据客户端的不同的请求决定不同的view进行响应, 如 http://www.sxrczx.com/rest.json http://www.sxrczx.com/rest.xml --><bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver"> <!-- 设置为true以忽略对Accept Header的支持--> <property name="ignoreAcceptHeader" value="true"/> <!-- 在没有扩展名时即: "http://www.sxrczx.com/rest" 时的默认展现形式 --> <property name="defaultContentType" value="text/html"/> <!-- 扩展名至mimeType的映射,即 http://www.sxrczx.com/rest.json 映射为 application/json --> <property name="mediaTypes"> <map> <entry key="json" value="application/json" /> <entry key="xml" value="application/xml" /> </map> </property> <!-- 用于开启 http://www.sxrczx.com/rest?format=json 的支持 --> <property name="favorParameter" value="false"/> <property name="viewResolvers"> <list> <bean class="org.springframework.web.servlet.view.BeanNameViewResolver" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/pages"/> <property name="suffix" value=".jsp"></property> </bean> </list> </property>
<property name="defaultViews"> <list> <!-- for application/json --> <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" /> <!-- for application/xml --> <!-- <bean class="org.springframework.web.servlet.view.xml.MarshallingView" > <property name="marshaller"> <bean class="org.springframework.oxm.xstream.XStreamMarshaller"/> </property> </bean>
--> </list> </property> </bean>
=======================================================================================================================Spring配置appContext.xml(freemarker/json)<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver"> <property name="order" value="1" /> <property name="favorParameter" value="false" /> <property name="ignoreAcceptHeader" value="true" /> <property name="defaultContentType" value="application/json" /> <property name="mediaTypes"> <map> <entry key="json" value="application/json" /> </map> </property> <property name="viewResolvers"> <list> <!-- 配置freemarker作为视图层 --> <bean id="freeMarkerViewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver"> <property name="cache" value="true" /> <property name="order" value="0" /> <property name="prefix" value="" /> <property name="suffix" value=".htm" /> <property name="contentType" value="text/html;charset=utf-8" /> <!-- 把contextPath暴露给freemaker，前端可以通过${request.getContextPath()} 来获取上下文路径 <property name="requestContextAttribute" value="request"/> --> <property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView"/> </bean> </list> </property> <property name="defaultViews"> <list> <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" /> </list> </property></bean> <!-- Freemarker --><bean id="freeMarkerViewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver"> <property name="cache" value="true" /> <property name="order" value="0" /> <property name="prefix" value="" /> <property name="suffix" value=".htm" /> <property name="contentType" value="text/html;charset=utf-8" /> <!-- 把contextPath暴露给freemaker，前端可以通过￥{request.getContextPath()} 来获取上下文路径 <property name="requestContextAttribute" value="request"/> --> <property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView" /></bean>
<!-- ftl参数配置 --><bean id="freemarkerConfiguration" class="org.springframework.beans.factory.config.PropertiesFactoryBean"> <property name="location" value="/WEB-INF/config/ftl/freemarker.properties"/></bean><bean id="freemarkerConfig" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer"> <property name="defaultEncoding" value="utf-8"/> <property name="templateLoaderPath" value="/WEB-INF/template"/> <property name="freemarkerSettings" ref="freemarkerConfiguration"/></bean>freemarker.properties
datetime_format=yyyy-MM-dd HH:mm:ssdate_format=yyyy-MM-ddtime_format=HH:mm:ssnumber_format=0.######;boolean_format=true,false#auto_import="/common/index.ftl" as uiwhitespace_stripping=truedefault_encoding=UTF-8tag_syntax=square_bracketurl_escaping_charset=UTF-8#开启默认容错，既null时，默认使用""代替classic_compatible=true
联系客服
