Spring mvc 從零搭建
以eclipse 為例
一：
new Dynamic Web Project
（如果沒有web.xml，輸入完專案名點下一步，勾選Generate web.xml deployment descriptor）
二：
在WebContent 寫一個靜態頁面 hello.html(試試web工程能否正常執行)
放入 tomcat 執行
http://localhost:1234/spring_mvc/hello.html
web程式正常執行
三：
編寫web.xml
配置spring mvc
以下是web.xml全部的配置
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>spring mvc</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 配置SpringMVC分發器，攔截所有請求 -->
<servlet>
<servlet-name>spring_mvc_test</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/springMvc-servlet.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>spring_mvc_test</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
四：
編寫springMvc-servlet.xml
放在與web.xml同級目錄下
內容如下
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:annotation-driven >
</mvc:annotation-driven>
<!-- 自動掃描controller包下的所有類，使其認為是spring mvc的控制器 路徑即為類路徑 -->
<context:component-scan base-package="com.Springmvc.Controller">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<context:component-scan base-package="com.Springmvc.Service"/>
<!-- <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />
--><bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
</beans>
這一步要注意的
路徑一定要指對，這個地方會掃描該目錄下所有的@Controller註解註解的類
五 ：
引入 spring mvc必要的jar
spring-framework.RELEASE.jar
官方的下載路徑如下
http://repo.spring.io/release/org/springframework/spring/
這裡我選的是 spring-framework-4.3.6.RELEASE
解壓縮，放入web- inf 的lib裡
六：
按標準，編寫 程式碼
我的目錄如下
HelloController
HelloService
七：
編寫完成直接啟動tomcat
報什麼錯，解決什麼問題
我這裡報錯
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/spring_mvc_test]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:753)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:729)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:621)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1835)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.getDeclaredFields(Unknown Source)
at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:256)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:132)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:336)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:786)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:307)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:95)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5213)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
... 10 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
... 24 more
五月 24, 2018 2:24:07 下午 org.apache.catalina.startup.HostConfig deployDescriptor
嚴重: Error deploying configuration descriptor E:\workspace_lee\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\conf\Catalina\localhost\spring_mvc_test.xml
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/spring_mvc_test]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:757)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:729)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:621)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1835)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
這是因為缺少commons-logging 的 jar包
官方下載路徑
http://commons.apache.org/proper/commons-logging/download_logging.cgi
引入再啟動
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.spring.service.HelloService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
是因為沒有沒有掃描service的配置
在spring servlet .xml中增加配置
<context:component-scan base-package="com.spring.service"/>
八：
解決完錯誤，
瀏覽器輸入路徑報錯
這個地方要說明，spring mvc返回的字串是檢視，但是我controller裡返回的是物件，所以無法解析這個物件，這裡要把返回的物件轉成json
網上有很多解決辦法，我這裡下載jar包 fastjson （網上有好多，官網需要郵件驗證比較麻煩）
引入jar
spring servlet .xml增加配置
<mvc:annotation-driven >
<mvc:message-converters register-defaults="true">
<!-- 避免IE執行AJAX時,返回JSON出現下載檔案 -->
<bean id="fastJsonHttpMessageConverter" class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>application/json;charset=UTF-8</value>
</list>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
【最後】
大功告成，接下來配合mybatis研究好了再繼續修改