spring boot实现过滤器和拦截器demo

整理文档，搜刮出一个spring boot实现过滤器和拦截器demo ，稍微整理精简一下做下分享。

拦截器定义:

@WebServlet
public class ActionInterceptor implements HandlerInterceptor {

  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
      throws Exception {
    // System.out.println(">>>MyInterceptor1>>>>>>>在请求处理之前进行调用（Controller方法调用之前）");

    // 获取系统时间
    Calendar ca = Calendar.getInstance();
    int hour = ca.get(Calendar.HOUR_OF_DAY);
    // 设置限制运行时间 0-4点
    if (hour < 4) {
      return true;
    }
    return false;
  }

  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
      ModelAndView modelAndView) throws Exception {
    // System.out.println(">>>MyInterceptor1>>>>>>>请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）");

  }

  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
      throws Exception {
    // System.out.println(">>>MyInterceptor1>>>>>>>在整个请求结束之后被调用，也就是在DispatcherServlet
    // 渲染了对应的视图之后执行（主要是用于进行资源清理工作）");
  }
}

拦截器使用:  关于注解 我使用的是@Component  其实也可能声明成配置

@Component
public class ApplicationConfig {extends WebMvcConfigurerAdapter 

  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    // 多个拦截器组成一个拦截器链
    // addPathPatterns 用于添加拦截规则
    // excludePathPatterns 用户排除拦截
    registry.addInterceptor(new ActionInterceptor()).addPathPatterns("/service/extract/json/**");
    super.addInterceptors(registry);
  }
}

过滤器:

定义:

public class ActionFilter implements Filter {

  @Override
  public void init(FilterConfig filterConfig) throws ServletException {

  }

  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
      throws IOException, ServletException {
    // 获取系统时间
    Calendar ca = Calendar.getInstance();
    int hour = ca.get(Calendar.HOUR_OF_DAY);
    // 设置限制运行时间 0-4点
    if (hour < 4) {
      HttpServletResponse httpResponse = (HttpServletResponse) response;
      httpResponse.setCharacterEncoding("UTF-8");
      httpResponse.setContentType("application/json; charset=utf-8");
      
      // 消息
      Map messageMap = new HashMap<>();
      messageMap.put("status", "1");
      messageMap.put("message", "此接口可以请求时间为:0-4点");
      ObjectMapper objectMapper=new ObjectMapper();
      String writevalueAsString = objectMapper.writevalueAsString(messageMap);
      response.getWriter().write(writevalueAsString);
      
    } else {
      chain.doFilter(request, response);
    }

  }

  @Override
  public void destroy() {

  }

}

使用:

@Component
public class ApplicationConfig { 


  @Bean
  public FilterRegistrationBean filterRegistrationBean() {
    FilterRegistrationBean registrationBean = new FilterRegistrationBean();
    ActionFilter actionFilter = new ActionFilter();
    registrationBean.setFilter(actionFilter);
    List urlPatterns = new ArrayList();
    urlPatterns.add("/service/extract/json/*");
    registrationBean.setUrlPatterns(urlPatterns);
    return registrationBean;
  }
  

}

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