RESTful API的拦截方式 (过滤器Filter)拦截器(Interceptor)切片(Aspect)

优先级按排序

1 过滤器(Filter) 最先进入拦截,只能获取到response,request
2 拦截器(Interceptor) 可以获取到执行的类名,方法名
3 切片(Aspect) 可以获取到参数

具体使用哪一个看业务需求吧.

1 过滤器(Filter)

自定义Filter

package com.imooc.web.filter;
import org.springframework.stereotype.Component;
import java.io.IOException;
import java.util.Date;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
@Component  // 增加一个注解即可使用,不需要其他配置,会拦截所有请求
public class TimeFilter implements Filter {
    @Override
    public void destroy() {
        System.out.println("time filter destroy");
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        System.out.println("time filter start");
        long start = new Date().getTime();
        chain.doFilter(request, response); // 继续执行程序,不调用doFilter 不会往下执行
        System.out.println("time filter 耗时:"+ (new Date().getTime() - start));
        System.out.println("time filter finish");
    }
    @Override
    public void init(FilterConfig arg0) throws ServletException {
        // 程序启动会加载
        System.out.println("time filter init");
    }
}

　 如果是引用第三方的Filter 使用方法:

package com.imooc.web.config;
import java.util.ArrayList;
import java.util.List;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.imooc.web.filter.TimeFilter;
@Configuration
public class WebConfig {
    @Bean
    public FilterRegistrationBean timeFilter() {
        // 注册第三方Filter
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        TimeFilter timeFilter = new TimeFilter();
        registrationBean.setFilter(timeFilter);
        // 需要拦截的url
        List<String> urls = new ArrayList<>();
        urls.add("/*");
        registrationBean.setUrlPatterns(urls);
        return registrationBean;
    }
}

2 拦截器(Interceptor)

　　2.1自定义Interceptor

package com.imooc.web.interceptor;
import java.util.Date;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
 
@Component
public class TimeInterceptor implements HandlerInterceptor {
    // 先进入该方法
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        System.out.println("preHandle");
        System.out.println(((HandlerMethod)handler).getBean().getClass().getName());
        System.out.println(((HandlerMethod)handler).getMethod().getName());
        request.setAttribute("startTime", new Date().getTime());
        return true; // 返回true才能继续执行controller
    }
    // 如果Controller方法抛出了异常,不会进入该方法
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");
        Long start = (Long) request.getAttribute("startTime");
        System.out.println("time interceptor 耗时:"+ (new Date().getTime() - start));
 
    }
    // 不管方法是不是抛出异常 都会进入该方法
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        System.out.println("afterCompletion");
        Long start = (Long) request.getAttribute("startTime");
        System.out.println("time interceptor 耗时:"+ (new Date().getTime() - start));
        System.out.println("ex is "+ex);
 
    }
 
}

　　　2.2 注入自定义的Interceptor

package com.imooc.web.config;
 
import com.imooc.web.interceptor.TimeInterceptor;
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 TimeInterceptorConfig extends WebMvcConfigurerAdapter {
    // 自定义的Interceptor
    @Autowired
    private TimeInterceptor timeInterceptor;
 
    // 注入spring
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(timeInterceptor);
    }
 
}

3 切片(Aspect)

自定义切片

package com.imooc.web.aspect;
import java.util.Date;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class TimeAspect {
   // 切入具体的方法,拦截UserController的所有方法
   @Around("execution(* com.imooc.web.controller.UserController.*(..))")
   public Object handleControllerMethod(ProceedingJoinPoint pjp) throws Throwable {
      System.out.println("time aspect start");
      Object[] args = pjp.getArgs(); // 可以获取方法参数
      for (Object arg : args) {
         System.out.println("arg is "+arg);
      }
      long start = new Date().getTime();
      Object object = pjp.proceed(); // 继续往下执行Controller
      System.out.println("time aspect 耗时:"+ (new Date().getTime() - start));
      System.out.println("time aspect end");
      return object;
   }
}