SpringMVC-注解配置

代替web.xml

• 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，这个类反过来又会查找实现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

public class WebInit 
        extends AbstractAnnotationConfigDispatcherServletInitializer {

    /**
     * 指定spring的配置类
     * @return
     */
    @Override
    protected Class[] getRootConfigClasses() {
        return new Class[]{SpringConfig.class};
    }

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

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

    /**
     * 添加过滤器
     * @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};
    }
}

代替spring的配置文件

@Configuration
public class SpringConfig {
	//ssm整合之后，spring的配置信息写在此类中
}

代替SpringMVC的配置文件

/**
 * 代替SpringMVC的配置文件：
 * 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、异常处理    8、拦截器
 */
//将当前类标识为一个配置类
@Configuration
//1、扫描组件
@ComponentScan("com.atguigu.mvc.controller")
//5、mvc注解驱动
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

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

    //8、拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        TestInterceptor testInterceptor = new TestInterceptor();
        registry.addInterceptor(testInterceptor).addPathPatterns("/**");
    }

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

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

    //7、异常处理
    @Override
    public void configureHandlerExceptionResolvers(
            List resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = 
                new SimpleMappingExceptionResolver();
        Properties prop = new Properties();
        prop.setProperty("java.lang.ArithmeticException", "error");
        exceptionResolver.setExceptionMappings(prop);
        exceptionResolver.setExceptionAttribute("exception");
        resolvers.add(exceptionResolver);
    }

    //配置生成模板解析器
    @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;
    }

}

 测试

@RequestMapping("/")
public String index(){
    return "index";
}