一、自定义过滤器
创建一个过滤器,实现javax.servlet.Filter接口,并重写其中的init、doFilter、destory方法。
- package com.example.filter;
- import java.io.IOException;
- import javax.servlet.Filter;
- import javax.servlet.FilterChain;
- import javax.servlet.FilterConfig;
- import javax.servlet.ServletException;
- import javax.servlet.ServletRequest;
- import javax.servlet.ServletResponse;
- import javax.servlet.annotation.WebFilter;
- /**
- * 实现javax.servlet.Filter,覆盖其三个方法
- * @author Administrator
- *
- */
- @WebFilter(filterName="customFilter",urlPatterns="/*")
- public class CustomFilter implements Filter{
- @Override
- public void destroy() {
- System.out.println("CustomFilter过滤器销毁");
- }
- @Override
- public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
- throws IOException, ServletException {
- System.out.println("CustomFilter指定过滤器操作......");
- //执行操作后必须doFilter
- chain.doFilter(request, response);
- }
- @Override
- public void init(FilterConfig arg0) throws ServletException {
- System.out.println("CustomFilter初始化......");
- }
- }
二、自定义监听器
创建一个过滤器,实现ServletContextListener接口
- package com.example.listener;
- import javax.servlet.ServletContextEvent;
- import javax.servlet.ServletContextListener;
- import javax.servlet.annotation.WebListener;
- /**
- * 实现ServletContextListener,覆盖其两个方法
- * @author Administrator
- *
- */
- @WebListener
- public class CustomListener implements ServletContextListener{
- @Override
- public void contextDestroyed(ServletContextEvent servletContext) {
- System.out.println("servletContext销毁......");
- }
- @Override
- public void contextInitialized(ServletContextEvent servletContext) {
- System.out.println("servletContext初始化......");
- }
- }
创建一个session监听器,监听session的创建和销毁
- package com.example.listener;
- import javax.servlet.annotation.WebListener;
- import javax.servlet.http.HttpSessionEvent;
- import javax.servlet.http.HttpSessionListener;
- /**
- * 实现HttpSessionListener接口,监视session的动态
- * @author Administrator
- *
- */
- @WebListener
- public class SessionListener implements HttpSessionListener{
- @Override
- public void sessionCreated(HttpSessionEvent session) {
- System.out.println("session创建成功......");
- }
- @Override
- public void sessionDestroyed(HttpSessionEvent session) {
- System.out.println("session销毁......");
- }
- }
三、自定义拦截器
步骤:
1、创建自己的拦截器实现HandlerInterceptor接口
2、创建自己的拦截器链,继承WebMvcConfigurerAdapter类,重写addInterceptors方法。
3、实例化自己的拦截器,并加入到拦截器链中。
拦截器一:
- package com.example.Interceptor;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.web.servlet.HandlerInterceptor;
- import org.springframework.web.servlet.ModelAndView;
- public class CustomInterceptor implements HandlerInterceptor {
- @Override
- public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object,
- Exception exception) throws Exception {
- //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)
- System.out.println("3. 整个请求结束之后被调用......CustomInterceptor1......");
- }
- @Override
- public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object, ModelAndView view)
- throws Exception {
- // 请求处理之后进行调用,但是在视图被渲染之前
- System.out.println("2. 请求处理之后进行调用,但是在视图被渲染之前......CustomInterceptor1......");
- }
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {
- // 在请求处理之前进行调用
- System.out.println("1. 在请求处理之前进行调用......CustomInterceptor1......");
- // 只有返回true才会继续向下执行,返回false取消当前请求
- return true;
- }
- }
拦截器二:
- package com.example.Interceptor;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.web.servlet.HandlerInterceptor;
- import org.springframework.web.servlet.ModelAndView;
- public class CustomInterceptor2 implements HandlerInterceptor {
- @Override
- public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object,
- Exception exception) throws Exception {
- //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)
- System.out.println("3. 整个请求结束之后被调用......CustomInterceptor2......");
- }
- @Override
- public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object, ModelAndView view)
- throws Exception {
- // 请求处理之后进行调用,但是在视图被渲染之前
- System.out.println("2. 请求处理之后进行调用,但是在视图被渲染之前......CustomInterceptor2......");
- }
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {
- // 在请求处理之前进行调用
- System.out.println("1. 在请求处理之前进行调用......CustomInterceptor2......");
- // 只有返回true才会继续向下执行,返回false取消当前请求
- return true;
- }
- }
自定义拦截器链并加入自定义的拦截器
- package com.example.adapter;
- import org.springframework.context.annotation.Configuration;
- import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
- import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
- import com.example.Interceptor.CustomInterceptor;
- import com.example.Interceptor.CustomInterceptor2;
- /**
- * 继承WebMvcConfigurerAdapter,复写addInterceptors方法
- * @author Administrator
- *
- */
- @Configuration
- public class WebAdapter extends WebMvcConfigurerAdapter{
- @Override
- public void addInterceptors(InterceptorRegistry registry) {
- //众多的拦截器组成了一个拦截器链
- /**
- * 主要方法说明:
- * addPathPatterns 用于添加拦截规则
- * excludePathPatterns 用户排除拦截
- */
- registry.addInterceptor(new CustomInterceptor()).addPathPatterns("/*");
- registry.addInterceptor(new CustomInterceptor2()).addPathPatterns("/*");
- super.addInterceptors(registry);
- }
- }
- 来源:网络