利用springboot如何实现一个过滤器功能？相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
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<String, Object> 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<String> urlPatterns = new ArrayList<String>();
urlPatterns.add("/service/extract/json/*");
registrationBean.setUrlPatterns(urlPatterns);
return registrationBean;
}
}看完上述内容，你们掌握利用springboot如何实现一个过滤器功能的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注亿速云行业资讯频道，感谢各位的阅读！
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