This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Hi, I was wondering if someone can explain me what do the following lines mean in plain english. The GET method should be safe, that is, without any side effects for which users are held responsible. For example, most form queries have no side effects. If a client request is intended to change stored data, the request should use some other HTTP method. The GET method should also be idempotent, meaning that it can be safely repeated. Sometimes making a method safe also makes it idempotent. For example, repeating queries is both safe and idempotent, but buying a product online or modifying data is neither safe nor idempotent.side effects for which users are held responsible
This means (if I understand correctly) that an Http GET request should retireve data only, that is make no modifications to persistent data. This makes sense if you look at the name, GET (to get data from). In order to persistent data, an HTTP POST request should be sent (to post data to). If this is adopted, then idempotency would be achieved, that is the method would perfrom the same function (return the same data) no matter how many times it is called. Hope this explains things at least a little more clearly. Cheers Sam
<a href="http://www.samjdalton.com" target="_blank" rel="nofollow">Sam Dalton</a>,<br />Co-author of [http://www.amazon.com/exec/obidos/tg/detail/-/1590592255/qid=1068633302//ref=sr_8_xs_ap_i0_xgl14/104-4904002-9274339?v=glance&s=books&n=507846]Professional JSP 2.0[/URL] (October 2003)<br />Co-author of <a href="http://www.amazon.com/exec/obidos/ASIN/1861007701/ref=ase_electricporkchop" target="_blank" rel="nofollow">Professional SCWCD Certification</a><br />Co-author of <a href="http://www.amazon.com/exec/obidos/ASIN/186100561X/ref=ase_electricporkchop" target="_blank" rel="nofollow">Professional Java Servlets 2.3</a>