拦截器基础应用

拦截器基础应用

创建拦截器

@Component
public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle方法执行....");
        return false;
    }

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

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

配置拦截器

@Configuration
public class MVCConfig implements WebMvcConfigurer {
    @Autowired
    private MyInterceptor myInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(myInterceptor)
                .addPathPatterns("/user/findAll")
                .addPathPatterns("/public.html")
                .excludePathPatterns("/index.html");
    }
}

aop切面

第一步

第二步

第三步

@Aspect
@Component
public class logingAdvice {
    @Pointcut("execution( * com.example.demo.controller.*.*(..))")
    public void myPointcut() {
        System.out.println("myPointcut");
    }

    @Around("@annotation(loging)")
    public Object applicationLog(ProceedingJoinPoint pjp) throws Throwable {
        System.out.println("applicationLog");
        return "{\"code\":300,\"msg\":\"访问频繁\"}";
    }
}

@Aspect
@Component
public class logingAdvice {
    @Pointcut("execution( * com.example.demo.controller.*.*(..))")
    public void myPointcut() {
        System.out.println("myPointcut");
    }

    @Around("myPointcut()")
    public Object applicationLog(ProceedingJoinPoint pjp) throws Throwable {
        System.out.println("applicationLog");
        return pjp.proceed();
    }
}