springboot实现自定义mvc组件

springboot实现自定义mvc组件

如果你想实现一些定制化功能，只需要写这个组件，然后将它交给springboot管理，springboot会给我们自动装配

以下是spring官方文档解释

由官方文档可知，想要自定义组件，需要实现以下步骤

• 写一个配置类，加上@Configuration注解
• 实现WebMvcConfigurer接口
• 不添加@EnableWebMvc注解

示例：自定义拦截器和视图解析器

• 自定义拦截器

  package com.yl.handler;
  
  import org.springframework.web.servlet.HandlerInterceptor;
  import org.springframework.web.servlet.ModelAndView;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  public class MyHandler implements HandlerInterceptor {
      @Override
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
          if (request.getParameter("username").equals("yl")){
              return true;
          }else {
              return false;
          }
      }
  
      @Override
      public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
  
      }
  
      @Override
      public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
  
      }
  }
  

• 注册拦截器和视图解析器

  package com.yl.configration;
  
  import com.yl.handler.MyHandler;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
  import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
  import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
  
  @Configuration
  public class WebMvcConfig implements WebMvcConfigurer {
  
      /**
       * 添加拦截器，springboot已经做好了静态资源映射
       * @param registry
       */
      @Override
      public void addInterceptors(InterceptorRegistry registry) {
          registry.addInterceptor(new MyHandler()).addPathPatterns("/**").excludePathPatterns("/register");
      }
  
      /**
       * 添加视图解析器
       * @param registry
       */
      @Override
      public void addViewControllers(ViewControllerRegistry registry) {
          registry.addViewController("/index.html").setViewName("index");
      }
  }