在 SpringBoot中使用攔截器

攔截器介面 HandlerInterceptor

public interface HandlerInterceptor {


    boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception;


    void postHandle(
            HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
            throws
 
 Exception;


    void afterCompletion(
            HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception;

}

實現自定義的攔截器需要實現HandlerInterceptor介面

例如：LogHandlerInteceptor

public class LogHandlerInterceptor implements HandlerInterceptor
 
 {

    /**
     * controller 執行之前呼叫
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        System.out.println("------preHandle-----");
        return true;
    }

    /**
     * controller 執行之後，且頁面渲染之前呼叫
     */
 

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

    /**
     * 頁面渲染之後呼叫，一般用於資源清理操作
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        System.out.println("------afterCompletion-----");

    }

}

註冊攔截器

@Configuration
public class MyWebConfig extends WebMvcConfigurerAdapter{

    /**
     * 註冊 攔截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LogHandlerInterceptor());
    }

}

測試：

UserController

@RestController
public class UserController {

    @GetMapping("/user/home")
    public String home(){
        System.out.println("--- user home ---");
        return "user home";
    }

}