简介
使用配置类和注解代替web.xml和SpringMVC配置文件的功能
在Servlet3.0环境中,容器会在类路径中查找实现javax.servlet.ServletContainerInitializer接口的类,如果找到的话就用它来配置Servlet容器。 Spring提供了这个接口的实现,名为SpringServletContainerInitializer,这个类又会查找实现WebApplicationInitializer的类并将配置的任务交给它们来完成。Spring3.2引入了一个便利的WebApplicationInitializer基础实现,名为AbstractAnnotationConfigDispatcherServletInitializer,当我们的类扩展了AbstractAnnotationConfigDispatcherServletInitializer并将其部署到Servlet3.0容器的时候,容器会自动发现它,并用它来配置Servlet上下文。
意思就是容器会自动发现继承了AbstractAnnotationConfigDispatcherServletInitializer的子类,并用它来配置servlet上下文。(用来代替web.xml)
注解类代替web.xml
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package com.hxut.rj1192.annoation; import org.springframework.web.filter.CharacterEncodingFilter; import org.springframework.web.filter.HiddenHttpMethodFilter; import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer; import javax.servlet.Filter; //代替web.xml filter过滤器 spring springmvc的配置类 dispracture的映射路径 public class webXml extends AbstractAnnotationConfigDispatcherServletInitializer { // 指定spring配置类 @Override protected Class<?>[] getRootConfigClasses() { return new Class[] {SpringConfig. class }; } // 指定springmvc配置类 @Override protected Class<?>[] getServletConfigClasses() { return new Class[]{SpringMvcConfig. class }; } // 指定dispracture的映射路径 即url-pattern @Override protected String[] getServletMappings() { return new String[]{ "/" }; } //注册编码过滤器 @Override protected Filter[] getServletFilters() { CharacterEncodingFilter encodingFilter = new CharacterEncodingFilter(); encodingFilter.setEncoding( "UTF-8" ); encodingFilter.setForceRequestEncoding( true ); HiddenHttpMethodFilter hiddenHttpMethodFilter = new HiddenHttpMethodFilter(); return new Filter[]{encodingFilter, hiddenHttpMethodFilter}; } } |
注解类代替Spring-mvc.xml
Spring-mvc配置文件(不管是xml还是注解的类)有如下八个功能
- 视图解析器
- 扫描包的范围(组件扫描)
- view-controller(只返回视图的控制方法)
- defalut-servlet-handler 静态资源处理
- mvc注解驱动
- 文件上传解析器
- 异常处理
- 拦截器
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package com.hxut.rj1192.annoation; import com.hxut.rj1192.InterceptorRegistry01; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.web.context.ContextLoader; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.multipart.commons.CommonsMultipartResolver; import org.springframework.web.servlet.HandlerExceptionResolver; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ViewResolver; import org.springframework.web.servlet.config.annotation.*; import org.springframework.web.servlet.handler.SimpleMappingExceptionResolver; import org.thymeleaf.spring5.SpringTemplateEngine; import org.thymeleaf.spring5.view.ThymeleafViewResolver; import org.thymeleaf.templatemode.TemplateMode; import org.thymeleaf.templateresolver.ITemplateResolver; import org.thymeleaf.templateresolver.ServletContextTemplateResolver; import java.util.List; import java.util.Properties; //1视图解析器 2扫描包的范围(组件扫描) 3view-controller(只返回视图的控制方法) 4defalut-servlet-handler 静态资源处理和 //5 mvc注解驱动 6文件上传解析器 7异常处理 8拦截器 //代替springmvc的配置文件 //扫描包的范围(组件扫描) @ComponentScan ( "com.hxut.rj1192" ) //开启MVC注解驱动 @EnableWebMvc @Configuration public class SpringMvcConfig implements WebMvcConfigurer { //配置视图解析器 // 这个注解是将类放进ioc容器中 因为web.xml中就是嵌套的, @Bean public ITemplateResolver templateResolver() { WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext(); // ServletContextTemplateResolver需要一个ServletContext作为构造参数,可通过WebApplicationContext 的方法获得 ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver( webApplicationContext.getServletContext()); templateResolver.setPrefix( "/WEB-INF/templates/" ); templateResolver.setSuffix( ".html" ); templateResolver.setCharacterEncoding( "UTF-8" ); templateResolver.setTemplateMode(TemplateMode.HTML); return templateResolver; } //生成模板引擎并为模板引擎注入模板解析器 @Bean public SpringTemplateEngine templateEngine(ITemplateResolver templateResolver) { SpringTemplateEngine templateEngine = new SpringTemplateEngine(); templateEngine.setTemplateResolver(templateResolver); return templateEngine; } //生成视图解析器并未解析器注入模板引擎 @Bean public ViewResolver viewResolver(SpringTemplateEngine templateEngine) { ThymeleafViewResolver viewResolver = new ThymeleafViewResolver(); viewResolver.setCharacterEncoding( "UTF-8" ); viewResolver.setTemplateEngine(templateEngine); return viewResolver; } //default-servlet configuure @Override public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) { WebMvcConfigurer. super .configureDefaultServletHandling(configurer); } @Override public void addInterceptors(InterceptorRegistry registry) { InterceptorRegistry01 interceptorRegistry= new InterceptorRegistry01(); // addPathPatterns("/");是设置拦截的url // excludePathPatterns(); 是设置不拦截的url registry.addInterceptor(interceptorRegistry).addPathPatterns( "/" ); } //视图控制器 @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController( "/hello" ).setViewName( "succes" ); } //配置文件上传解析器 @Bean public CommonsMultipartResolver multipartResolver(){ CommonsMultipartResolver commonsMultipartResolver= new CommonsMultipartResolver(); return commonsMultipartResolver; } //配置异常映射 @Override public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) { SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver(); Properties prop = new Properties(); prop.setProperty( "java.lang.ArithmeticException" , "error" ); //设置异常映射 exceptionResolver.setExceptionMappings(prop); //设置共享异常信息的键 exceptionResolver.setExceptionAttribute( "ex" ); resolvers.add(exceptionResolver); } } |
全用xml写:
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<? 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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd" > <!--2.扫描包的范围(组件扫描)--> < context:component-scan base-package = "com.hxut.rj1192.zyk" /> <!-- 1.配置Thymeleaf视图解析器 --> < bean id = "viewResolver" class = "org.thymeleaf.spring5.view.ThymeleafViewResolver" > < property name = "order" value = "1" /> < property name = "characterEncoding" value = "UTF-8" /> < property name = "templateEngine" > < bean class = "org.thymeleaf.spring5.SpringTemplateEngine" > < property name = "templateResolver" > < bean class = "org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver" > < property name = "prefix" value = "/WEB-INF/templates/" /> < property name = "suffix" value = ".html" /> < property name = "templateMode" value = "HTML5" /> < property name = "characterEncoding" value = "UTF-8" /> </ bean > </ property > </ bean > </ property > </ bean > <!--4.静态资源处理--> < mvc:default-servlet-handler /> <!--5.mvc注解驱动--> < mvc:annotation-driven /> < mvc:interceptors > < bean class = "com.hxut.rj1192.zyk.interceptor.interceptor01" /> </ mvc:interceptors > < bean class = "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" > < property name = "exceptionMappings" > < props > < prop key = "java.lang.ArithmeticException" >error</ prop > </ props > </ property > < property name = "exceptionAttribute" value = "ex" ></ property > </ bean > <! --3.view-controller--> < mvc:view-controller path = "/testView" view-name = "success" ></ mvc:view-controller > <! --4.文件上传解析器--> < bean id = "multipartResolver" class = "org.springframework.web.multipart.commons.CommonsMultipartResolver" > </ bean > <! --7.异常处理--> < bean class = "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" > < property name = "exceptionMappings" > < props > < prop key = "java.lang.ArithmeticException" >error</ prop > </ props > </ property > <!-- 将错误信息放到ex这个变量中,并放进model中--> < property name = "exceptionAttribute" value = "ex" ></ property > </ bean > <! --8.拦截器--> < mvc:interceptors > < ref bean = "first" ></ ref > < ref bean = "second" ></ ref > </ mvc:interceptors > </ beans > |
拦截器文件
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package com.hxut.rj1192; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class InterceptorRegistry01 implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println( "prehandle 执行" ); return true ; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println( "posthandle 执行" ); HandlerInterceptor. super .postHandle(request, response, handler, modelAndView); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println( "afterhandle 执行" ); HandlerInterceptor. super .afterCompletion(request, response, handler, ex); } } |
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原文链接:https://blog.csdn.net/sharesb/article/details/124715584