Spring高级应用---拦截器

1.核心API  HanlerInterceptor    WebMvcConfigureAdaptor

2.流程：

a.定义拦截器（实现HanlerInterceptor接口，或继承HandlerInterceptorAdaptor类）;

默认方法中绑定了请求和响应可在请求和响应中相应的处理

M：preHandle postHandle

request.setAttribute（"tango","beauty"）；

b.将拦截器加入应用的上下文环境，实现WebMvcConfigureAdaptor

M：addInterceptors（Registry registery）方法

 registery.addInterceptor(自定义的拦截器);

3.示例代码

自定义拦截器

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class TangoInteceptor extends HandlerInterceptorAdapter{

    @Override

    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)

    throws Exception {

    long startTime = System.currentTimeMillis();

    response.getWriter().println("请求开始！");

    request.setAttribute("startTime",startTime);

        return true;

    }

@Override

public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,

ModelAndView modelAndView) throws Exception {

long endtime=System.currentTimeMillis();

Long startTime =(Long) request.getAttribute("startTime");

System.out.println("本次请求共用了时间"+new Long(endtime-startTime)+"ms");

response.getWriter().println("请求结束！"+"本次请求共用了时间"+new Long(endtime-startTime)+"ms");

}

}

注册拦截器

@TangoConfig("com.tango.spring.Intercepter")

public class InterCeptorConfig extends WebMvcConfigurerAdapter{

  @Bean

  public TangoInteceptor tangoInteceptor() {

  return new TangoInteceptor();

  }

@Override

public void addInterceptors(InterceptorRegistry registry) {

registry.addInterceptor(tangoInteceptor());

}

}

测试的Conttroller

@RestController

public class TangoController {

@RequestMapping("/tango")

public void tangoTest() {

System.out.println("世界真奇妙");

}

}