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
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
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(Listresolvers) { 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:
拦截器文件
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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