从零开始学JAVA(08)-使用SpringMVC4 Restful 风格引用静态文件 css/js/png
在写完helloworld后想给网页加点样式(*.css),结果怎么也显示不了,百度了很多种方法后试行尝试,试验成功并记录下来,方便以后查看。
时隔两年,继续学习JAVA,太久没学了,忘记得差不多,还好以前写的helloworld,还能用。
一、关于开发环境
- eclipse-jee-neon-1a-win32
- Jdk 1.8u112 (32位版本)
- SpringMVC 4.3.4.RELEASE
- apache-tomcat-8.5.8
二、helloworld.jsp文件中的引用的样式表为 style.css 放在res/css文件夹中
<link rel="stylesheet" href="res/css/style.css">
三、加载静态资源 方法一
引用上一章的代码(http://www.cnblogs.com/lin557/p/4305405.html),需要修改web.xml与mydispatcher-servlet.xml两个文件,
原文件内容如下:
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name>Spring MVC</display-name> <servlet> <servlet-name>mydispatcher</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mydispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/mydispatcher-servlet.xml</param-value> </context-param> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> </web-app>
修改为:
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name>Spring MVC</display-name> <servlet> <servlet-name>mydispatcher</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mydispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/mydispatcher-servlet.xml</param-value> </context-param> <!-- 使用默认的方式进行处理 --> <servlet-mapping> <servlet-name>default</servlet-name> <url-pattern>*.css</url-pattern> </servlet-mapping> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> </web-app>
这里增加了*.css的处理
<!-- 使用默认的方式进行处理 --> <servlet-mapping> <servlet-name>default</servlet-name> <url-pattern>*.css</url-pattern> </servlet-mapping>
当然可以换成别的,比如说*.js,*.png....等等,方法如下:
<servlet-mapping> <servlet-name>default</servlet-name> <url-pattern>*.css</url-pattern> <url-pattern>*.js</url-pattern> <url-pattern>*.png</url-pattern> <url-pattern>*.gif</url-pattern> </servlet-mapping>
配置完web.xml,还需要修改mydispatcher-servlet.xml,启用default-servlet-handler
mydispatcher-servlet.xml 原文如下:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <context:component-scan base-package="com.web.controller" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix"> <value>/WEB-INF/views/</value> </property> <property name="suffix"> <value>.jsp</value> </property> </bean> </beans>
修改为:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 默认的注解映射的支持 --> <mvc:annotation-driven /> <!-- 对静态资源文件的访问 --> <mvc:default-servlet-handler /> <context:component-scan base-package="com.web.controller" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix"> <value>/WEB-INF/views/</value> </property> <property name="suffix"> <value>.jsp</value> </property> </bean> </beans>
最后:需要把静态文件(css,jsp,png,gif)放在根目录(WebContent或WebRoot)下才能被成功被页面引用。这种方法只能指向根目录(我不知道是否可以换成其他目录),如果要支持多种类型的文件,需要在web.xml里进行多次配置,否则会出现404的错误提示。
此方法目标结构为:
四、加载静态资源 方法二
web.xml保持不变,且不能有第一种方法中的代码
<!-- 使用默认的方式进行处理 这里不能出现 不然会出问题 --> <servlet-mapping> <servlet-name>default</servlet-name> <url-pattern>*.css</url-pattern> </servlet-mapping>
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name>Spring MVC</display-name> <servlet> <servlet-name>mydispatcher</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mydispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/mydispatcher-servlet.xml</param-value> </context-param> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener> </web-app>
修改mydispatcher-servlet.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 默认的注解映射的支持 --> <mvc:annotation-driven /> <mvc:resources mapping="/res/**" location="/WEB-INF/res/" cache-period="31556926"/> <context:component-scan base-package="com.web.controller" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix"> <value>/WEB-INF/views/</value> </property> <property name="suffix"> <value>.jsp</value> </property> </bean> </beans>
这种方法优点在于不需要额外的配置,只要把静态文件(css/js/png/jpg/gif等等)放在res文件夹中,都能可以直接调用。而且可以指定目录的位置。
此方法目录结构为
五、总结
从初学者的角度看,方法二感觉比较方便。
2016-12-07 by lin