SpringBoot的HandlerInterceptorAdapter攔截器

在SpringBoot中我們可以使用HandlerInterceptorAdapter這個適配器來實現自己的攔截器。這樣就可以攔截所有的請求並做相應的處理。

　　詳細可參考文章：https://www.cnblogs.com/weianlai/p/11358768.html

1. 攔截器執行順序是按照Spring配置文件中定義的順序而定的。
2. 會先按照順序執行所有攔截器的preHandle方法，一直遇到return false為止，比如第二個preHandle方法是return false，則第三個以及以后所有攔截器都不會執行。若都是return true，則按順序加載完preHandle方法。
3. 然后執行主方法（自己的controller接口），若中間拋出異常，則跟return false效果一致，不會繼續執行postHandle，只會倒序執行afterCompletion方法。
4. 在主方法執行完業務邏輯（頁面還未渲染數據）時，按倒序執行postHandle方法。若第三個攔截器的preHandle方法return false，則會執行第二個和第一個的postHandle方法和afterCompletion（postHandle都執行完才會執行這個，也就是頁面渲染完數據后，執行after進行清理工作）方法。（postHandle和afterCompletion都是倒序執行）

自定義一個攔截器需繼承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 {

        // 請求地址
        String requestUrl = request.getRequestURI().toString();
        String userName = request.getRemoteUser();
        // 無需攔截直接訪問的地址
        String[] allowUrls = new String[] { "/api/Jurisdiction/getMenuList", "/logout", "/",
                "/api/user/getCurrentUser", "/swagger-resources/configuration/ui",
                "/swagger-resources" };
        // 請求IP
        String ip = GetIpUtil.getIp(request);
        logger.info("request請求的用戶為：" + userName);
        logger.info("request請求的IP為：" + ip);
        logger.info("request請求的URL為：" + requestUrl);

        // 判斷請求地址是否無需攔擊
        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", "您沒有訪問權限");
            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.........");
    }
}

　　使攔截器生效需繼承WebMvcConfigurerAdapter（WebMvcConfigurer）類，可添加多個攔截器，按先后順序執行

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);
    }

}