使用内容协商让Spring MVC支持xml json等格式输出
在dispatcher-servlet.xml里配置
<!-- Content Negotiating View Resolver --><bean value="true" /><property name="defaultContentType" value="text/html" /><property name="mediaTypes"><map><entry key="html" value="text/html" /><entry key="xml" value="application/xml" /><entry key="json" value="application/json" /></map></property><property name="favorParameter" value="false" /><property name="viewResolvers"><list><bean value="false" /><property name="contentType" value="text/html" /><property name="prefix" value="" /><property name="suffix" value=".html.ftl" /><property name="exposeSpringMacroHelpers" value="true" /><property name="requestContextAttribute" value="rc" /></bean><bean value="false" /><property name="contentType" value="application/xml" /><property name="prefix" value="" /><property name="suffix" value=".xml.ftl" /><property name="exposeSpringMacroHelpers" value="true" /><property name="requestContextAttribute" value="rc" /></bean><bean value="false" /><property name="contentType" value="application/json" /><property name="prefix" value="" /><property name="suffix" value=".json.ftl" /><property name="exposeSpringMacroHelpers" value="true" /><property name="requestContextAttribute" value="rc" /></bean></list></property></bean>