今天学习一下RESTFul api拦截
大概有三种方式
一、通过Filter这个大家很熟悉了吧,这是java规范的一个过滤器，他会拦截请求。在springboot中一般有两种配置方式。
这种过滤器拦截并不知道你用的是哪一个Controller处理也不知道你用哪一个方法处理。
（1）第一种直接写类实现这个接口。代码如下这个要使用Component注解，当你你请求服务器的时候他会对每一个请求进行处理。
package com.nbkj.webFilter;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import java.io.IOException;
import java.util.Date;
@Component
public class TimerFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("Time filter init");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("Time filter start");
long startTime = new Date().getTime();
filterChain.doFilter(servletRequest, servletResponse);
System.out.println("time filter:"+(new Date().getTime()-startTime));
System.out.println("time filter finish");
}
@Override
public void destroy() {
System.out.println("Time filter destroy");
}
}
（2）第二种可以在WebConfig中配置，这种配置方式为了使用第三方的Filter没有@Compont注解所以使用。代码如下
package com.nbkj.config;
import com.nbkj.webFilter.TimerFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.ArrayList;
import java.util.List;
/**
* Web配置
*
* @author hsj
* @Configuration 这个注解声明这个类是配置类
* @create 2017-11-11 18:00
**/
@Configuration
public class WebConfig {
@Bean
public FilterRegistrationBean timeFilter() {
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
TimerFilter timerFilter = new TimerFilter();
registrationBean.setFilter(timerFilter);
List<String> urls = new ArrayList<>();
urls.add("/*");
registrationBean.setUrlPatterns(urls);
return registrationBean;
}
}
二、使用Interceptor这种事spring框架自己带的拦截器，代码如下 它会处理自己写的拦截器，也会拦截的拦截BasicErrorController
可以拿到处理的Controller和拿到处理的方法 但是拿不到具体的请求参数。
package com.nbkj.interceptor;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.persistence.Convert;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Date;
/**
* this is spring interceptor
*
* @author hsj
* @create 2017-11-11 18:16
**/
@Component
public class TimeInterceptor implements HandlerInterceptor {
/**
* 控制器方法处理之前
*
* @param httpServletRequest
* @param httpServletResponse
* @param handler
* @return
* @throws Exception
*/
@Override
public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler) throws Exception {
System.out.println("preHandle");
System.out.println(((HandlerMethod) handler).getBean().getClass().getName());
System.out.println(((HandlerMethod) handler).getMethod().getName());
httpServletRequest.setAttribute("startTime", new Date().getTime());
return false;
}
/**
* 控制器方法处理之后
* 控制器方法调用不抛异常调用
*
* @param httpServletRequest
* @param httpServletResponse
* @param o
* @param modelAndView
* @throws Exception
*/
@Override
public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("postHandle");
Long startTime = (Long) httpServletRequest.getAttribute("startTime");
System.out.println("time interceptor 耗时" + (new Date().getTime() - startTime));
}
/**
* 控制器方法抛不抛异常都会被调用
*
* @param httpServletRequest
* @param httpServletResponse
* @param o
* @param e
* @throws Exception
*/
@Override
public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
System.out.println("afterCompletion");
Long startTime = (Long) httpServletRequest.getAttribute("startTime");
System.out.println("time interceptor 耗时" + (new Date().getTime() - startTime));
System.out.println("ex is" + e);
}
}
package com.nbkj.config;
import com.nbkj.interceptor.TimeInterceptor;
import com.nbkj.webFilter.TimerFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import java.util.ArrayList;
import java.util.List;
/**
* Web配置
*
* @author hsj
* @Configuration 这个注解声明这个类是配置类
* @create 2017-11-11 18:00
**/
@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
@Autowired
private TimeInterceptor timeInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(timeInterceptor);
}
}
三、使用Aspect切片，代码如下
使用环绕通知，切入要切入的类，当请求的时候回拦截下来，这样可以获取拦截的方法的参数
package com.nbkj.aspect;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
import java.util.Date;
/**
* this is a acpect
* 切入点
* 在那些方法上起作用
* 在什么时候起作用
*
* @author hsj
* @create 2017-11-11 20:52
**/
@Aspect
@Component
public class TimeAspect {
@Around("execution(* com.nbkj.controller.UserController.*(..))")
public Object handleControllerMethod(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
System.out.println("time aspect start");
Object[] args = proceedingJoinPoint.getArgs();
for (Object arg : args) {
System.out.println(arg.getClass().getName());
System.out.println("arg is " + arg);
}
long startTime = new Date().getTime();
Object obj = proceedingJoinPoint.proceed();
System.out.println("time aspect 耗时" + (new Date().getTime() - startTime));
System.out.println("time aspect end");
return obj;
}
}
过滤器（Filter） ：可以拿到原始的http请求，但是拿不到你请求的控制器和请求控制器中的方法的信息。
拦截器（Interceptor）：可以拿到你请求的控制器和方法，却拿不到请求方法的参数。
切片 （Aspect） : 可以拿到方法的参数，但是却拿不到http请求和响应的对象
