建立初始化類，代替web.xml

在Servlet3.0環境中，容器會在類路徑中查詢實現javax.servlet.ServletContainerInitializer介面的類，如果找到的話就用它來配置Servlet容器。

Spring提供了這個介面的實現，名為SpringServletContainerInitializer，這個類反過來又會查詢實現WebApplicationInitializer的類並將配置的任務交給它們來完成。Spring3.2引入了一個便利的WebApplicationInitializer基礎實現，名為AbstractAnnotationConfigDispatcherServletInitializer，當我們的類擴充套件了AbstractAnnotationConfigDispatcherServletInitializer並將其部署到Servlet3.0容器的時候，容器會自動發現它，並用它來配置Servlet上下文。

public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {

    /**

     * 指定spring的配置類

     * @return

     */

    @Override

    protected Class<?>[] getRootConfigClasses() {

        return new Class[]{SpringConfig.class};

    }

    /**

     * 指定SpringMVC的配置類

     * @return

     */

    @Override

    protected Class<?>[] getServletConfigClasses() {

        return new Class[]{WebConfig.class};

    }

    /**

     * 指定DispatcherServlet的對映規則，即url-pattern

     * @return

     */

    @Override

    protected String[] getServletMappings() {

        return new String[]{"/"};

    }

    /**

     * 新增過濾器

     * @return

     */

    @Override

    protected Filter[] getServletFilters() {

        CharacterEncodingFilter encodingFilter = new CharacterEncodingFilter();

        encodingFilter.setEncoding("UTF-8");

        encodingFilter.setForceRequestEncoding(true);

        HiddenHttpMethodFilter hiddenHttpMethodFilter = new HiddenHttpMethodFilter();

        return new Filter[]{encodingFilter, hiddenHttpMethodFilter};

    }

}

建立SpringConfig配置類，代替spring的配置檔案

@Configuration

public class SpringConfig {

	//ssm整合之後，spring的配置資訊寫在此類中

}

建立WebConfig配置類，代替SpringMVC的配置檔案

@Configuration

//掃描元件

@ComponentScan("com.gonghr.springmvc.controller")

//開啟MVC註解驅動

@EnableWebMvc

public class WebConfig implements WebMvcConfigurer {

    //使用預設的servlet處理靜態資源

    @Override

    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {

        configurer.enable();

    }

    //配置檔案上傳解析器

    @Bean

    public CommonsMultipartResolver multipartResolver(){

        return new CommonsMultipartResolver();

    }

    //配置攔截器

    @Override

    public void addInterceptors(InterceptorRegistry registry) {

        FirstInterceptor firstInterceptor = new FirstInterceptor();

        registry.addInterceptor(firstInterceptor).addPathPatterns("/**");

    }

    //配置檢視控制

    @Override

    public void addViewControllers(ViewControllerRegistry registry) {

        registry.addViewController("/").setViewName("index");

    }

    //配置異常對映

    @Override

    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {

        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();

        Properties prop = new Properties();

        prop.setProperty("java.lang.ArithmeticException", "error");

        //設定異常對映

        exceptionResolver.setExceptionMappings(prop);

        //設定共享異常資訊的鍵

        exceptionResolver.setExceptionAttribute("ex");

        resolvers.add(exceptionResolver);

    }

    //配置生成模板解析器

    @Bean

    public ITemplateResolver templateResolver() {

        WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext();

        // ServletContextTemplateResolver需要一個ServletContext作為構造引數，可通過WebApplicationContext 的方法獲得

        ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(

                webApplicationContext.getServletContext());

        templateResolver.setPrefix("/WEB-INF/templates/");

        templateResolver.setSuffix(".html");

        templateResolver.setCharacterEncoding("UTF-8");

        templateResolver.setTemplateMode(TemplateMode.HTML);

        return templateResolver;

    }

    //生成模板引擎併為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;

    }

    //生成檢視解析器並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;

    }

}

測試功能

@RequestMapping("/")

public String index(){

    return "index";

}