五：SpringBoot-多個攔截器配置和使用場景

1、攔截器簡介

攔截器，請求的接口被訪問之前，進行攔截然後在之前或之後加入某些操作。攔截是AOP的一種實現策略。 攔截器主要用來按照指定規則拒絕請求。

1.1 攔截器中應用

• Token令牌驗證
• 請求數據校驗
• 用戶權限校驗
• 放行指定接口

2、攔截器用法

2.1 編寫兩個攔截器

自定義類實現HandlerInterceptor接口

2.1.1 OneInterceptor 攔截器

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 攔截器一
 */
public class OneInterceptor implements HandlerInterceptor {
   private static final Logger LOGGER = LoggerFactory.getLogger(OneInterceptor.class.getName());
   @Override
   public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object o) throws Exception {
     String url =String.valueOf(request.getRequestURL()) ;
     LOGGER.info("1、url=="+url);
     // 放開攔截
     return true;
 }

 @Override
 public void postHandle(HttpServletRequest httpServletRequest,
   HttpServletResponse httpServletResponse,
   Object o, ModelAndView modelAndView) throws Exception {
   LOGGER.info("1、postHandle");
 }
 @Override
 public void afterCompletion(HttpServletRequest httpServletRequest,
   HttpServletResponse httpServletResponse,
   Object o, Exception e) throws Exception {
   LOGGER.info("1、afterCompletion");
 }
}

2.1.2 TwoInterceptor 攔截器

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 攔截器二
 */
public class TwoInterceptor implements HandlerInterceptor {
   private static final Logger LOGGER = LoggerFactory.getLogger(TwoInterceptor.class.getName());
   @Override
   public boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object o) throws Exception {
    String url =String.valueOf(request.getRequestURL()) ;
    LOGGER.info("2、url=="+url);
    // 放開攔截
    return true;
 }
 @Override
 public void postHandle(HttpServletRequest httpServletRequest,HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
     LOGGER.info("2、postHandle");
 }

 @Override
 public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    LOGGER.info("2、afterCompletion");
 }
}

2.2 Web配置文件中注入攔截器

import com.boot.intercept.intercept.OneInterceptor;
import com.boot.intercept.intercept.TwoInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
/**
 * Web配置文件
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
 public void addInterceptors(InterceptorRegistry registry) {
 // 攔截所有路徑
 // 註冊自定義兩個攔截器
 registry.addInterceptor(new OneInterceptor()).addPathPatterns("/**");
 registry.addInterceptor(new TwoInterceptor()).addPathPatterns("/**");
 }
}

2.3 編寫測試接口

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class InterceptController {
 @RequestMapping("/reqUrl")
 public String reqUrl (){
 return "success" ;
 }
}

2.4 訪問測試接口

日誌輸出內容如下

intercept.OneInterceptor : 1、url==http://127.0.0.1:8005/reqUrl
intercept.TwoInterceptor : 2、url==http://127.0.0.1:8005/reqUrl
intercept.TwoInterceptor : 2、postHandle
intercept.OneInterceptor : 1、postHandle
intercept.TwoInterceptor : 2、afterCompletion
intercept.OneInterceptor : 1、afterCompletionla

攔截器的攔截順序，是按照Web配置文件中注入攔截器的順序執行的。