SpringBoot的HandlerInterceptorAdapter拦截器

在SpringBoot中我们可以使用HandlerInterceptorAdapter这个适配器来实现自己的拦截器。这样就可以拦截所有的请求并做相应的处理。

　　详细可参考文章：https://www.cnblogs.com/weianlai/p/11358768.html

1. 拦截器执行顺序是按照Spring配置文件中定义的顺序而定的。
2. 会先按照顺序执行所有拦截器的preHandle方法，一直遇到return false为止，比如第二个preHandle方法是return false，则第三个以及以后所有拦截器都不会执行。若都是return true，则按顺序加载完preHandle方法。
3. 然后执行主方法（自己的controller接口），若中间抛出异常，则跟return false效果一致，不会继续执行postHandle，只会倒序执行afterCompletion方法。
4. 在主方法执行完业务逻辑（页面还未渲染数据）时，按倒序执行postHandle方法。若第三个拦截器的preHandle方法return false，则会执行第二个和第一个的postHandle方法和afterCompletion（postHandle都执行完才会执行这个，也就是页面渲染完数据后，执行after进行清理工作）方法。（postHandle和afterCompletion都是倒序执行）

自定义一个拦截器需继承HandlerInterceptorAdapter

package cn.jsfund.ngdp.support.config;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.alibaba.fastjson.JSONObject;

import cn.jsfund.ngdp.support.exception.ServiceException;
import cn.jsfund.ngdp.support.util.GetIpUtil;
import cn.jsfund.ngdp.support.web.service.PermissionUserService;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import java.io.PrintWriter;

@Configuration
public class SecurityInterceptor extends HandlerInterceptorAdapter {

    private static Logger logger = LoggerFactory.getLogger(SecurityInterceptor.class);

    @Autowired
    private PermissionUserService permissionUserService;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
            Object handler) throws Exception {

        // 请求地址
        String requestUrl = request.getRequestURI().toString();
        String userName = request.getRemoteUser();
        // 无需拦截直接访问的地址
        String[] allowUrls = new String[] { "/api/Jurisdiction/getMenuList", "/logout", "/",
                "/api/user/getCurrentUser", "/swagger-resources/configuration/ui",
                "/swagger-resources" };
        // 请求IP
        String ip = GetIpUtil.getIp(request);
        logger.info("request请求的用户为：" + userName);
        logger.info("request请求的IP为：" + ip);
        logger.info("request请求的URL为：" + requestUrl);

        // 判断请求地址是否无需拦击
        for (String url : allowUrls) {
            if (requestUrl.equals(url)) {
                return true;
            }
        }
        boolean checkFlag = false;
        if (permissionUserService.checkMenuJurisdiction(userName, requestUrl) > 0) {
            checkFlag = true;
        }

        if (!checkFlag) {
            JSONObject res = new JSONObject();
            res.put("code", ServiceException.ERROR_VALIDATE);
            res.put("msg", "您没有访问权限");
            response.setCharacterEncoding("UTF-8");
            response.setContentType("application/json; charset=utf-8");
            PrintWriter out = null;
            out = response.getWriter();
            out.append(res.toString());
        }
        return checkFlag;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle.........");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
            Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion.........");
    }
}

　　使拦截器生效需继承WebMvcConfigurerAdapter（WebMvcConfigurer）类，可添加多个拦截器，按先后顺序执行

package cn.jsfund.ngdp.support.config;

import org.springframework.beans.factory.annotation.Autowired;
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 InterceptorConf extends WebMvcConfigurerAdapter {

    @Autowired
    private SecurityInterceptor securityInterceptor;
    @Autowired
    private TestInterceptor testInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(securityInterceptor);
        registry.addInterceptor(testInterceptor);
    }

}