(1)问题:如何在Web项目中配置Spring的IoC容器?
答:如果需要在Web项目中使用Spring的IoC容器,可以在Web项目配置文件web.xml中做出如下配置:
<!-- Spring监听器 -->
<listener> <listener-class>org.springframework.web. contex t. ContextLoaderListener</listener-class> </listener>
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(2)如何在Web项目中配置Spring MVC?
答:要使用Spring MVC需要在Web项目配置文件中web.xml中配置其前端控制器DispatcherServlet:
<!-- Spring MVC servlet -->
<servlet> <servlet-name>SpringMVC</servlet-name> <servlet-class>org.springframework.web. servlet. DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value> classpath:spring/spring-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping> <servlet-name>SpringMVC</servlet-name> <url-pattern>/</url-pattern>
</servlet-mapping>
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spring-mvc.xml 文件内容:
<?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-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 自动扫描该包,使SpringMVC认为包下用了@controller注解的类是控制器 --> <mvc:annotation-driven/> <mvc:default-servlet-handler/> <context:component-scan base-package="com.XXXX.controller"> <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service" /> </context:component-scan> <!-- 定义跳转的文件的前后缀 ,视图模式配置--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/"/> <property name="suffix" value=".jsp"/> </bean> <!-- 启用默认配置 --> <mvc:annotation-driven> <mvc:message-converters register-defaults="true"> <!-- 配置Fastjson支持 --> <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>application/json</value> <value>text/html;charset=UTF-8</value> </list> </property> </bean> </mvc:message-converters> </mvc:annotation-driven> <!-- 配置文件上传,如果没有使用文件上传可以不用配置,当然如果不配,那么配置文件中也不必引入上传组件包 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 默认编码 --> <property name="defaultEncoding" value="utf-8"/> <!-- 文件大小最大值 --> <property name="maxUploadSize" value="1048576000"/> <!-- 内存中的最大值 --> <property name="maxInMemorySize" value="10240"/> </bean> </beans>
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所以 <mvc:annotation-driven> 标签主要是用来帮助我们 处理请求映射,决定是哪个controller的哪个方法来处理当前请求,异常处理。 <context:component-scan/>标签: 它的实现类是org.springframework.context.annotation.ComponentScanBeanDefinitionParser. 用来扫描该包内被@Repository @Service @Controller的注解类,然后注册到工厂中。
并且context:component-scan激活@ required。@ resource,@ autowired、@PostConstruct @PreDestroy @PersistenceContext @PersistenceUnit。使得在适用该bean的时候用@Autowired就行了。主要用于对实体的注解交给spring容器管理
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<annotaion-driven/>标签:包含以下两个实例: RequestMappingHandlerMapping 处理@RequestMapping注解的 RequestMappingHandlerAdapter 处理@Controller注解的控制器类