How to write .spec file to check JRE version in Fedora 10

I am using fedora 10 linux. I have created an RPM for my software it works fine. But I want the follwing feature "If I开发者_StackOverflow社区 install RPM it will check whether JRE 1.5 or greater is availble in that system if available then install the RPM otherwise I want to show the URL to download the JRE.

Is there anything that I have to write in my .spec file

How can I achieve this type of functionality.

Thanks Sunil Kumar Sahoo

I insert the following line to check for jre 1.5 or greater in your spec file Requires:jre >= 1.5