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 MVCdisplay-name>
<servlet>
<servlet-name>mydispatcherservlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
servlet-class>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>mydispatcherservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>/WEB-INF/mydispatcher-servlet.xmlparam-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 MVCdisplay-name>
<servlet>
<servlet-name>mydispatcherservlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
servlet-class>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>mydispatcherservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>/WEB-INF/mydispatcher-servlet.xmlparam-value>
context-param>
<servlet-mapping>
<servlet-name>defaultservlet-name>
<url-pattern>*.cssurl-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
<servlet-mapping>
<servlet-name>defaultservlet-name>
<url-pattern>*.cssurl-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>defaultservlet-name> <url-pattern>*.cssurl-pattern> <url-pattern>*.jsurl-pattern> <url-pattern>*.pngurl-pattern> <url-pattern>*.gifurl-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>.jspvalue>
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">
<mvc:annotation-driven />
<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>.jspvalue>
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
default
*.css
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 MVCdisplay-name>
<servlet>
<servlet-name>mydispatcherservlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
servlet-class>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>mydispatcherservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>/WEB-INF/mydispatcher-servlet.xmlparam-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">
<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>.jspvalue>
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