<div>
check the Last-Modified value in the http response header
</div>


check the Last-Modified value in the http response header

<div>
what if the header doesn't include the info? are there any other ways?
</div>


what if the header doesn't include the info? are there any other ways?

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not unless they including it some other custom header<br />

</div>


not unless they including it some other custom header


<div>
calboronster:<br />
<br />
My crawling application wants to detect the changes of a web page ever since last crawl. The solution you provided seems that a good check can be done only on the server side which may not help my case.<br />
<br />
Thanks
</div>


calboronster:

My crawling application wants to detect the changes of a web page ever since last crawl. The solution you provided seems that a good check can be done only on the server side which may not help my case.

Thanks

<div>
&gt;&gt;The solution you provided seems that a good check can be done only on the server side which may not help my case.<br />
<br />
I wonder why you accepted it then?<br />

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>>The solution you provided seems that a good check can be done only on the server side which may not help my case.

I wonder why you accepted it then?


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<div class="content wysiwyg-content">
Hi,<br />
<br />
As noted above, I want to use Java to detect a web page's last update time via httpresponse, etc. I don't want to save the web page's contents and verify through the contents.<br />
<br />
Thanks
</div>
</div>


Hi,

As noted above, I want to use Java to detect a web page's last update time via httpresponse, etc. I don't want to save the web page's contents and verify through the contents.

Thanks

How to know if a web page's last update time

The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems. Hypertext is structured text that uses logical links (hyperlinks) between nodes containing text. HTTP is the protocol to exchange or transfer hypertext. HTTP functions as a request-response protocol in the client-server computing model. HTTP is designed to permit intermediate network elements to improve or enable communications between clients and servers. HTTP is an application layer protocol designed within the framework of the Internet Protocol Suite; it presumes an underlying and reliable transport layer protocol.

HTTP Protocol

Java is a platform-independent, object-oriented programming language and run-time environment, designed to have as few implementation dependencies as possible such that developers can write one set of code across all platforms using libraries. Most devices will not run Java natively, and require a run-time component to be installed in order to execute a Java program.

Java

HTML (HyperText Markup Language) is the main markup language for creating web pages and other information to be displayed in a web browser, providing both the structure and content for what is sent from a web server through the use of tags. The current implementation of the HTML specification is HTML5.