SpringMVC注解配置

• • 1、创建初始化类，代替web.xml
  • 2、创建SpringConfig配置类，代替spring的配置文件
  • 3、创建SpringMVCConfig配置类，代替SpringMVC.xml的配置文件
  • 4、测试方法

使用配置类和注解代替web.xml和SpringMVC配置文件的功能

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。Spring提供了这个接口的实现，名为SpringServletContainerInitializer，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。

public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {

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

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

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

    // 添加过滤器
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter encodingFilter = new CharacterEncodingFilter();
        encodingFilter.setEncoding("UTF-8");
        encodingFilter.setForceRequestEncoding(true);
        HiddenHttpMethodFilter hiddenHttpMethodFilter = new HiddenHttpMethodFilter();
        return new Filter[]{encodingFilter, hiddenHttpMethodFilter};
    }
}

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

@Configuration
//扫描组件
@ComponentScan("com.ricky.controller")
//开启MVC注解驱动
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    // 使用默认的servlet处理静态资源
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    // 配置文件上传解析器
    @Bean
    public CommonsMultipartResolver multipartResolver(){
        return new CommonsMultipartResolver();
    }

    // 配置拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        FirstInterceptor firstInterceptor = new FirstInterceptor();
        registry.addInterceptor(firstInterceptor).addPathPatterns("/**");
    }
    
    // 配置视图控制
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
    }
    
    // 配置异常映射
	@Override
    public void configureHandlerExceptionResolvers(List resolvers) {
        SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();
        Properties prop = new Properties();
        prop.setProperty("java.lang.ArithmeticException", "error");
        // 设置异常映射
        exceptionResolver.setExceptionMappings(prop);
        // 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
    @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;
    }


}

@Controller
public class TestController {

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

    @RequestMapping("/demo")
    @ResponseBody
    public String demo() {
        int m = 1/0;
        return "hello springMVC";
    }

}