SpringMVC 拦截器实现权限统一校验

一、入门

 

 客户端发起请求进入DispatcherServlet，再进入我们自定义的拦截器，拦截器实现的是HandlerIntercepter接口，如果拦截成功，就向客服端返回拦截器响应信息；

如果验证通过，就进入对应的controller，然后结果一系列操作，返回controller响应信息

（二）、 SpringMVC拦截器配置及类初始化 

在dispatcher-servlet.xml文件设置mvc拦截器

<mvc:interceptors>
        <!-- 定义在这里，所有的都会拦截-->
        <!-- <bean></bean>-->
        <mvc:interceptor>
            <!---->
            <mvc:mapping path="/manage/**"/>
            <!--指定拦截器初始化类-->
            <bean class="com.mmall.controller.common.interceptor.AuthorityInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

创建拦截器初始化类AuthorityInterceptor

package com.mmall.controller.common.interceptor;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
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.util.Arrays;
import java.util.Iterator;
import java.util.Map;

// 拦截器初始化类
@Slf4j
public class AuthorityInterceptor implements HandlerInterceptor {
    // controller处理之前
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        log.info("preHandle");
        // 请求中Controller中的方法名
        HandlerMethod handlerMethod = (HandlerMethod) o;

        // 解析handlerMethod
        String methodName = handlerMethod.getMethod().getName();
        String className = handlerMethod.getBean().getClass().getSimpleName();

        //解析参数,具体的参数key以及value是什么，我们打印日志
        StringBuffer requestParamBuffer = new StringBuffer();
        Map paramMap = httpServletRequest.getParameterMap();
        Iterator it = paramMap.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            String mapKey = (String) entry.getKey();
            String mapValue = StringUtils.EMPTY;

            // httpServletRequest这个参数的map，里面的value返回的是一个String[]
            Object obj = entry.getValue();
            if (obj instanceof String[]) {
                String[] strs = (String[])obj;
                mapValue = Arrays.toString(strs);
            }
            requestParamBuffer.append(mapKey).append("=").append(mapValue);
        }

        // 还没有写完 
        return true;
    }

    // controller 处理之后
    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        log.info("postHandle");
    }

    // 所有处理完成后调用
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        log.info("afterCompletion");
    }
}