spring boot加入拦截器Interceptor过程解析

public class WebAppConfig extends WebMvcConfigurerAdapter 

public void addInterceptors(InterceptorRegistry registry){ 
} 

public class WebAppConfig extends WebMvcConfigurerAdapter{  
  public static void main(String[] args) { 
    SpringApplication.run(WebAppConfig.class, args); 
  }  
   
  /** 
   * 配置拦截器 
   * @author lance 
   * @param registry 
   */ 
  public void addInterceptors(InterceptorRegistry registry) { 
    registry.addInterceptor(new UserSecurityInterceptor()).addPathPatterns("/user/**"); 
  } 
} 
 
UserSecurityInterceptor代码 
public class UserSecurityInterceptor implements HandlerInterceptor { 
 
  @Override 
  public boolean preHandle(HttpServletRequest request, 
      HttpServletResponse response, Object handler) throws Exception { 
     
    return true; 
  }  
  @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 { 
  } 
}