Spring mvc 从零搭建
以eclipse 为例
一:
new Dynamic Web Project
(如果没有web.xml,输入完项目名点下一步,勾选Generate web.xml deployment descriptor)
二:
在WebContent 写一个静态页面 hello.html(试试web工程能否正常运行)
放入 tomcat 运行
http://localhost:1234/spring_mvc/hello.html
web程序正常运行
三:
编写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分发器,拦截所有请求 -->
<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:
编写springMvc-servlet.xml
放在与web.xml同级目录下
内容如下
<?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>
<!-- 自动扫描controller包下的所有类,使其认为是spring mvc的控制器 路径即为类路径 -->
<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>
这一步要注意的
路径一定要指对,这个地方会扫描该目录下所有的@Controller注解注解的类
五 :
引入 spring mvc必要的jar
spring-framework.RELEASE.jar
官方的下载路径如下
http://repo.spring.io/release/org/springframework/spring/
这里我选的是 spring-framework-4.3.6.RELEASE
解压缩,放入web- inf 的lib里
六:
按标准,编写 代码
我的目录如下
HelloController
HelloService
七:
编写完成直接启动tomcat
报什么错,解决什么问题
我这里报错
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
严重: 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)
这是因为缺少commons-logging 的 jar包
官方下载路径
http://commons.apache.org/proper/commons-logging/download_logging.cgi
引入再启动
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)}
是因为没有没有扫描service的配置
在spring servlet .xml中增加配置
<context:component-scan base-package="com.spring.service"/>
八:
解决完错误,
浏览器输入路径报错
这个地方要说明,spring mvc返回的字符串是视图,但是我controller里返回的是对象,所以无法解析这个对象,这里要把返回的对象转成json
网上有很多解决办法,我这里下载jar包 fastjson (网上有好多,官网需要邮件验证比较麻烦)
引入jar
spring servlet .xml增加配置
<mvc:annotation-driven >
<mvc:message-converters register-defaults="true">
<!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->
<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>
【最后】
大功告成,接下来配合mybatis研究好了再继续修改