AbstractAnnotationConfigDispatcherServletlnitializer

在 Servlet3.0 环境中，容器会在类路径中查找实现javax.servlet.ServletContainerlnitializer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SpringServletContainerlnitializer，这个类反过来又会查找实现WebApplicationlnitializer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 WebApplicationlnitializer基础实现，名为AbstractAnnotationConfigDispatcherServletlnitializer

当类扩展了AbstractAnnotationConfigDispatcherServletlnitializer并将其部署到 Servlet3.0 容器时，容器会自动发现它，并用它来配置Servlet 上下文

初始化类

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/**
 * web工程的初始化类，代替web.xml
 */
public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {
    /**
     * 指定Spring配置类
     *
     * @return
     */
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{SpringConfig.class};
    }

    /**
     * 指定SpringMVC配置类
     *
     * @return
     */
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }

    /**
     * 指定SpringMVC的映射规则，即url-pattern
     *
     * @return
     */
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    /**
     * 注册过滤器
     *
     * @return
     */
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
        characterEncodingFilter.setEncoding("UTF-8");
        characterEncodingFilter.setForceResponseEncoding(true);
        HiddenHttpMethodFilter hiddenHttpMethodFilter = new HiddenHttpMethodFilter();
        return new Filter[]{characterEncodingFilter, hiddenHttpMethodFilter};
    }
}

SpringMVC 配置类

SpringMVC 配置类清单

  • 1、扫描组件
  • 2、视图解析器
  • 3、view-controller
  • 4、default-servlet-handler
  • 5、MVC注解驱动
  • 6、文件上传解析器
  • 7、拦截器
  • 8、异常处理解析器
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// 标识为配置类
@Configuration
// ========== 1、扫描组件 ==========
@ComponentScan("com.vectorx.springmvc.controller")
// ========== 5、MVC注解驱动 ==========
@EnableWebMvc
public class WebConfig {}

视图解析器

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@Configuration
@ComponentScan("com.vectorx.springmvc.controller")
@EnableWebMvc
public class WebConfig {
    // ========== 2、视图解析器 ==========

    /**
     * 生成模板解析器
     *
     * @return
     */
    @Bean
    public ITemplateResolver templateResolver() {
        SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setPrefix("/WEB-INF/templates/");
        templateResolver.setSuffix(".html");
        templateResolver.setTemplateMode(TemplateMode.HTML);
        templateResolver.setCharacterEncoding("UTF-8");
        return templateResolver;
    }

    /**
     * 生成模板引擎并注入模板解析器
     *
     * @param templateResolver
     * @return
     */
    @Bean
    public ISpringTemplateEngine templateEngine(ITemplateResolver templateResolver) {
        SpringTemplateEngine templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);
        return templateEngine;
    }

    /**
     * 生成视图解析器并注入模板引擎
     *
     * @param templateEngine
     * @return
     */
    @Bean
    public ViewResolver viewResolver(ISpringTemplateEngine templateEngine) {
        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
        viewResolver.setOrder(1);
        viewResolver.setCharacterEncoding("UTF-8");
        viewResolver.setTemplateEngine(templateEngine);
        return viewResolver;
    }
}

WebMvcConfigurer

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@Configuration
@ComponentScan("com.vectorx.springmvc.controller")
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
    // 略...

    // ========== 3、view-controller ==========
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
    }
    // ========== 4、default-servlet-handler ==========
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    // ========== 7、拦截器 ==========
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new TestInterceptor()).addPathPatterns("/**");
    }

    // ========== 8、异常处理解析器 ==========
    @Override
    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();
        Properties properties = new Properties();
        properties.setProperty("java.lang.ArithmeticException", "error");
        exceptionResolver.setExceptionMappings(properties);
        exceptionResolver.setExceptionAttribute("ex");
        resolvers.add(exceptionResolver);
    }
}

文件上传解析器

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@Configuration
@ComponentScan("com.vectorx.springmvc.controller")
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
    // 略...

    // ========== 6、文件上传解析器 ==========
    @Bean
    public MultipartResolver multipartResolver() {
        MultipartResolver multipartResolver = new CommonsMultipartResolver();
        return multipartResolver;
    }
}

测试

访问首页

测试异常

附录：SpringMVC 配置类总览

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// 标识为配置类
@Configuration
// ========== 1、扫描组件 ==========
@ComponentScan("com.vectorx.springmvc.controller")
// ========== 5、MVC注解驱动 ==========
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    // ========== 2、视图解析器 ==========

    /**
     * 生成模板解析器
     *
     * @return
     */
    @Bean
    public ITemplateResolver templateResolver() {
        SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setPrefix("/WEB-INF/templates/");
        templateResolver.setSuffix(".html");
        templateResolver.setTemplateMode(TemplateMode.HTML);
        templateResolver.setCharacterEncoding("UTF-8");
        return templateResolver;
    }

    /**
     * 生成模板引擎并注入模板解析器
     *
     * @param templateResolver
     * @return
     */
    @Bean
    public ISpringTemplateEngine templateEngine(ITemplateResolver templateResolver) {
        SpringTemplateEngine templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);
        return templateEngine;
    }

    /**
     * 生成视图解析器并注入模板引擎
     *
     * @param templateEngine
     * @return
     */
    @Bean
    public ViewResolver viewResolver(ISpringTemplateEngine templateEngine) {
        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
        viewResolver.setOrder(1);
        viewResolver.setCharacterEncoding("UTF-8");
        viewResolver.setTemplateEngine(templateEngine);
        return viewResolver;
    }

    // ========== 3、view-controller ==========
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
    }

    // ========== 4、default-servlet-handler ==========
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    // ========== 6、文件上传解析器 ==========
    @Bean
    public MultipartResolver multipartResolver() {
        MultipartResolver multipartResolver = new CommonsMultipartResolver();
        return multipartResolver;
    }

    // ========== 7、拦截器 ==========
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new TestInterceptor()).addPathPatterns("/**");
    }

    // ========== 8、异常处理解析器 ==========
    @Override
    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();
        Properties properties = new Properties();
        properties.setProperty(ArithmeticException.class.getCanonicalName(), "error");
        exceptionResolver.setExceptionMappings(properties);
        exceptionResolver.setExceptionAttribute("ex");
        resolvers.add(exceptionResolver);
    }
}

总结

本届重点掌握

  • web 工程初始化的配置方法
  • SpringMVC 配置类的组件配置方法

附上导图，仅供参考