Spring Interceptor（***）的配置

• SpringBoot简单的Interceptor的配置，直接实现HandlerInterceptor接口，重写preHandle，postHandle，afterCompletion方法。

package com.bjut.config;

import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * Created by fan on 2019/8/29.
 */
@Component
public class TestInterceptor implements HandlerInterceptor {
    //视图渲染之后的操作
    @Override
    public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
            throws Exception {
        // TODO ...
    }
    //处理请求完成后视图渲染之前的处理操作
    @Override
    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
            throws Exception {
        // TODO ...
    }
    //进入controller层之前拦截请求
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object obj) throws Exception {
        System.out.println("getContextPath:" + request.getContextPath());
        System.out.println("getServletPath:" + request.getServletPath());
        System.out.println("getRequestURI:" + request.getRequestURI());
        System.out.println("getRequestURL:" + request.getRequestURL());
        System.out.println("getRealPath:" + request.getSession().getServletContext().getRealPath("image"));

        // 如果不是映射到方法直接通过
        if (!(obj instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) obj;
        Method method = handlerMethod.getMethod();
        //检查是否有@PassToken注解  有则跳过验证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            // TODO ...
        }
        return true;
    }
}

• 除此之外，还可以自定义拦截规则，addPathPatterns 用于添加拦截规则，excludePathPatterns 用于排除拦截，如addPathPatterns("//*") 可以拦截所有请求

@Configuration
public class WebMvcConfigurer extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new OneInterceptor()).addPathPatterns("/*/**").excludePathPatterns("/exclude/**");                                                                     
        super.addInterceptors(registry);
    }
}

• SpringMVC 拦截 /* 和 /** 的区别：

/* ：  匹配一级，即 /add , /query 等
/** ： 匹配多级，即 /add , /add/user, /add/user/user… 等

/：当请求为/user/login的时候可以被拦截，当为/page/login.html页面的时候不拦截