how to find http response time

Team,

I have the below problem and need your suggesstion.

Problem :

My application is deployed in Websphere with 3 JVM instance( 3 ports).
I need to monitor the application in all 3 ports and if one goes down, i need to get alert.Goes down means, if the port is not accessible in any port or if the HTTP request (clickng hyperlink/button click) takes more time to reach other page via any port.

a) for checking the the application availabilty , i can check the http response status code 200.
b) but if the request takes longer to get response, it is a problem.
so, i need to know the response time for the http request made.
Based on this, if it is greater than certain seconds, i can set alerts.

How to get this response time for any http request we make ? any api in java or any other ideas . Kindly share.

Thanks
David.

If this was my problem I would use HttpClient to create a Java application that could poll the servers and track the response time.
HttpClient is part of the Apache Commons open source project.

Bill