【SpringMVC】完全注解配置SpringMVC

創建初始化類，代替web.xml

在Servlet3.0環境中，容器會在類路徑中查找實現javax.servlet.ServletContainerInitializer接口的類，如果找到的話就用它來配置Servlet容器。
Spring提供了這個接口的實現，名為SpringServletContainerInitializer，這個類反過來又會查找實現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，當我們的類擴展了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的映射規則，即url-pattern
     * @return
     */
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    /**
     * 添加過濾器
     * @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};
    }
}

創建SpringConfig配置類，代替spring的配置文件

@Configuration
public class SpringConfig {
	//ssm整合之后，spring的配置信息寫在此類中
}

創建WebConfig配置類，代替SpringMVC的配置文件

@Configuration
//掃描組件
@ComponentScan("com.gonghr.springmvc.controller")
//開啟MVC注解驅動
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    //使用默認的servlet處理靜態資源
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    //配置文件上傳解析器
    @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("/**");
    }
    
    //配置視圖控制
    
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
    }
    
    //配置異常映射
    @Override
    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();
        Properties prop = new Properties();
        prop.setProperty("java.lang.ArithmeticException", "error");
        //設置異常映射
        exceptionResolver.setExceptionMappings(prop);
        //設置共享異常信息的鍵
        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作為構造參數，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;
    }

    //生成模板引擎並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;
    }

    //生成視圖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";
}