新建FirstInterceptor第一个拦截器
package com.example.demo1018.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 FirstInterceptor 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......FirstInterceptor......");
}
@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......FirstInterceptor......");
}
@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......FirstInterceptor......");
// 只有返回true才会继续向下执行，返回false取消当前请求
return true;
}}
新建SecondInterceptor第二个拦截器
package com.example.demo1018.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 SecondInterceptor 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......SecondInterceptor......");
}
@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......SecondInterceptor......");
}
@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......SecondInterceptor......");
// 只有返回true才会继续向下执行，返回false取消当前请求
return true;
}}
将拦截器组成一个拦截器链
package com.example.demo1018.interceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;@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 FirstInterceptor()).addPathPatterns("/*");
//拦截器SecondInterceptor不拦截hello
registry.addInterceptor(new SecondInterceptor()).addPathPatterns("/*").excludePathPatterns("/hello");
super.addInterceptors(registry);
}}