mvc纯注解驱动

1、自定义servlet容器初始化配置类，加载SpringMVC核心配置类，代替web.xml

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.filter.CharacterEncodingFilter;
import org.springframework.web.servlet.support.AbstractDispatcherServletInitializer;

import javax.servlet.DispatcherType;
import javax.servlet.FilterRegistration;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import java.util.EnumSet;

public class ServletContainersInitConfig extends AbstractDispatcherServletInitializer {
    //创建Servlet容器时，使用注解的方式加载SPRINGMVC配置类中的信息，并加载成WEB专用的ApplicationContext对象
    //该对象放入了ServletContext范围，后期在整个WEB容器中可以随时获取调用
    @Override
    protected WebApplicationContext createServletApplicationContext() {
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        ctx.register(SpringMVCConfiguration.class);
        return ctx;
    }

    //注解配置映射地址方式，服务于SpringMVC的核心控制器DispatcherServlet
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    @Override
    protected WebApplicationContext createRootApplicationContext() {
        return null;
    }

    //乱码处理作为过滤器，在servlet容器启动时进行配置，相关内容参看Servlet零配置相关课程
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        super.onStartup(servletContext);
        CharacterEncodingFilter cef = new CharacterEncodingFilter();
        cef.setEncoding("UTF-8");
        FilterRegistration.Dynamic registration = servletContext.addFilter("characterEncodingFilter", cef);
        registration.addMappingForUrlPatterns(EnumSet.of(DispatcherType.REQUEST,DispatcherType.FORWARD,DispatcherType.INCLUDE),false,"/*");
    }
}

2、配置mvc的bean并加载静态资源的配置，代替spring-mvc.xml

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
@ComponentScan(value = "com.itheima",includeFilters =
    @ComponentScan.Filter(type=FilterType.ANNOTATION,classes = {Controller.class})
    )
public class SpringMVCConfiguration implements WebMvcConfigurer{
    //注解配置放行指定资源格式
//    @Override
//    public void addResourceHandlers(ResourceHandlerRegistry registry) {
//        registry.addResourceHandler("/img/**").addResourceLocations("/img/");
//        registry.addResourceHandler("/js/**").addResourceLocations("/js/");
//        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
//    }

    //注解配置通用放行资源的格式
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();;
    }
}