注解配置SpringMVC

使用配置类和注解代替web.xml和Spring和SpringMVC配置文件的功能。

创建初始化类，代替web.xml

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。

web.xml的替代配置类

//代替web.xml
public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {@Override
//    设置一个配置类代替spring的配置文件protected Class<?>[] getRootConfigClasses() {return new Class[]{SpringConfig.class};}@Override
//    设置一个配置类代替springMVC的配置文件protected Class<?>[] getServletConfigClasses() {return new Class[]{WebConfig.class};}@Override
//    设置springmvc的前端控制器DispatcherServlet的url-patternprotected String[] getServletMappings() {return new String[]{"/"};}
//    设置当前的过滤器  ctrl+o@Overrideprotected Filter[] getServletFilters() {
//        创建编码过滤器CharacterEncodingFilter characterEncodingFilter=new CharacterEncodingFilter();characterEncodingFilter.setEncoding("UTF-8");characterEncodingFilter.setForceEncoding(true);
//        处理请求方式的过滤器HiddenHttpMethodFilter hiddenHttpMethodFilter=new HiddenHttpMethodFilter();return new Filter[]{characterEncodingFilter,hiddenHttpMethodFilter};}
}

SpringConfig配置类，代替spring的配置文件

applicationContext.xml的替代配置类

//代替spring的配置文件
@Configuration  //将当前类标识为配置类
public class SpringConfig {
//ssm整合之后，spring的配置信息写在此类中
}

WebConfig配置类，代替SpringMVC的配置文件

//代替springmvc的配置文件/*** 扫描组件，视图解析器，默认的servlet，mvc的注解驱动，视图控制器，文件上传解析器，拦截器，异常解析器*///扫描组件
@ComponentScan("com.atguigu.controller")//开启mvc的注解驱动
@EnableWebMvcpublic class WebConfig implements WebMvcConfigurer {@Override//默认的servlet处理静态资源  ctrl+opublic void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {configurer.enable();}@Overridepublic void addViewControllers(ViewControllerRegistry registry) {
//  配置视图解析器    addViewController : 设置浏览器发送的请求为/上下文路径的时候所设置的逻辑视图就是indexregistry.addViewController("/").setViewName("index");}//    文件上传解析器@Bean //可以将标识的方法的返回值作为bean进行管理，bean的id为方法的方法名public CommonsMultipartResolver multipartResolver(){return new CommonsMultipartResolver();}//    配置拦截器@Overridepublic void addInterceptors(InterceptorRegistry registry) {FirstInterceptor firstInterceptor=new FirstInterceptor();registry.addInterceptor(firstInterceptor).addPathPatterns("/**");}//    异常解析器@Overridepublic void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {SimpleMappingExceptionResolver exceptionResolver=new SimpleMappingExceptionResolver();Properties properties=new Properties();properties.setProperty("java.lang.ArithmeticException","error");//设置异常映射exceptionResolver.setExceptionMappings(properties);//设置共享异常信息的键exceptionResolver.setExceptionAttribute("ex");resolvers.add(exceptionResolver);}//配置生成模板解析器@Beanpublic 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 = newServletContextTemplateResolver(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@Beanpublic 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@Beanpublic ViewResolver viewResolver(SpringTemplateEngine templateEngine) {ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();viewResolver.setCharacterEncoding("UTF-8");viewResolver.setTemplateEngine(templateEngine);return viewResolver;}
}