TL；DR:

我怎么才能在ServletRequestListener.requestDestroyed期间拿到ServletResponse美元？

Short Version

在Java EE中，我想知道什么时候:

• 当请求启动时
• 当请求结束时

并且能够判断request和response个物体.

Long Version

在ASP.net世界中，如果您想知道请求何时开始和结束，您可以编写一个100:

public class ExampleModuleForThisQuestion : IHttpModule
{
}

然后在Web XML配置文件中注册您的"module":

web.config:

    <system.webServer>
        <modules>
            <add name="DoesntMatter" type="ExampleModuleForThisQuestion "/>
        </modules>
    </system.webServer> 

在您的模块中，您可以注册以下回调处理程序:

• BeginRequest个活动
• EndRequest个活动

然后，Web服务器基础设施调用您的100方法.这是您注册希望在请求启动和请求结束时接收通知的机会:

public class ExampleModuleForThisQuestion : IHttpModule
{
   public void Init(HttpApplication application)
   {
      application.BeginRequest += new EventHandler(beginRequest); //register the "BeginRequet" event
      application.EndRequest += new EventHandler(endRequest); //register the "EndRequest" event
   }
}

现在我们有了回调，当request starts分:

private void beginRequest(object sender, EventArgs e)
{
   HttpApplication application = (HttpApplication)sender;

   //Record the time the request started
   application.Context.Items["RequestStartTime"] = DateTime.Now;

   //We can even access the Request and Response objects
   application.ContenxtLog(application.Context.Request.Headers["User-Agent"]);
}

当request ends分的时候，我们有回拨:

private void endRequest(object sender, EventArgs e)
{
   HttpApplication application = (HttpApplication)sender;

   //We can even access the Request and Response objects

   //Get the response status code (e.g. 418 I'm a teapot)
   int statusCode = application.Context.Response.StatusCode;

   //Get the request method (e.g. GET, POST, BREW)
   String method = application.context.Request.RequestType;

   //Get the path from the request (e.g. /ViewCustomer)
   String path = application.context.Request.AppRelativeCurrentExecutionFilePath'
   
   //Get when the request started - that we recorded during "Begin Request"
   DateTime requestStartTime = (DateTime)application.Context.Items["RequestStartTime"];

   //And we can modify the response
   if ((DateTime.Now - requestStartTime).TotalSeconds = 17)
       application.Context.Response.StatusCode = 451;
}

Java Almost-Equivalent is ServletRequestListener

在Java apparently中，相应的技术是创建实现101接口的对象:

@WebListener
public class ExampleListenerForThisQuestion 
      implements javax.servlet.ServletRequestListener {

}

并将我们的listener注册到应用服务器，方法是将其包含在我们的Web XML配置文件中:

web.xml个

<listener>
    <listener-class>ExampleListenerForThisQuestion</listener-class>
</listener>

现在，我们可以实现在请求开始和结束时获取的requestInitialized和requestDestroyed方法:

public class ExampleListenerForThisQuestion 
      implements javax.servlet.ServletRequestListener {

   @Override
   public void requestInitialized(ServletRequestEvent sre) {
      ServletRequest sr = sre.getServletRequest();
      sr.setAttribute("requestStartTicks", getCurrentTickCount());

      HttpServletRequest request = (HttpServletRequest) sr;

      // e.g. "PUT /Customers/1234"
      System.out.printf("%s %s\r\n", request.getMethod());
   }

   @Override
   public void requestDestroyed(ServletRequestEvent sre) {
      ServletRequest sr = sre.getServletRequest();
      long requestStartTicks = (long)sr.getAttribute("requestStartTicks");

      HttpServletResponse response = (HttpServletRequest)...nothing, because i don't know how...

      // e.g. "226 IM Used"
      System.out.printf("%d %s\r\n", response.getStatus(), response.getStatusDescription());
   }
}

But how to get the response?

现在我收到了响应结束时的通知，我需要该请求的结果:

• 我需要http状态代码(例如424)
• 我需要http状态描述(例如Failed Dependency)
• 我需要判断响应头
• 我需要修改响应头

您注意到我上面代码中的这一行:

HttpServletResponse response = (HttpServletRequest)...nothing, because i don't know how...

我不知道如何获得response；这就是为什么我问Stackoverflow.