SpringBoot如何添加攔截器

/** 
 * 
 * 註冊攔截器 
 * Created by SYSTEM on 2017/8/16. 
 */  
public class WebAppConfig extends WebMvcConfigurerAdapter {  
  
    @Override  
    public void addInterceptors(InterceptorRegistry registry) {  
        //註冊自定義攔截器，添加攔截路徑和排除攔截路徑  
        registry.addInterceptor(new InterceptorConfig()).addPathPatterns("api/path/**").excludePathPatterns("api/path/login");  
    }  
}

在web開發的過程當中，爲了實現登陸權限驗證，咱們每每須要添加一個攔截器在用戶的的請求到達controller層的時候實現登陸驗證，那麼SpringBoot如何添加攔截器呢？

步驟以下：

1.繼承WebMvcConfigureAdapter類，覆蓋其addInterceptors接口,註冊咱們自定義的攔截器：

public class InterceptorConfig  implements HandlerInterceptor{  
  
    private static final Logger log = LoggerFactory.getLogger(InterceptorConfig.class);  
  
    /** 
     * 進入controller層以前攔截請求 
     * @param httpServletRequest 
     * @param httpServletResponse 
     * @param o 
     * @return 
     * @throws Exception 
     */  
    @Override  
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {  
  
        log.info("---------------------開始進入請求地址攔截----------------------------");  
        HttpSession session = httpServletRequest.getSession();  
        if(!StringUtils.isEmpty(session.getAttribute("userName"))){  
            return true;  
        }  
        else{  
            PrintWriter printWriter = httpServletResponse.getWriter();  
            printWriter.write("{code:0,message:\"session is invalid,please login again!\"}");  
            return false;  
        }  
  
    }  
  
    @Override  
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {  
        log.info("--------------處理請求完成後視圖渲染以前的處理操做---------------");  
    }  
  
    @Override  
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {  
        log.info("---------------視圖渲染以後的操做-------------------------0");  
    }  
}

這樣咱們就能夠在用戶請求到達controller層實現登陸攔截了，全部用戶請求都會被攔截，在prehandle方法進行登陸判斷，返回true則驗證經過，不然失敗