What's the reasoning for renaming the (jpackage) package name from java-1.5.0-sun to java-1.5.0-centos?
Offhand, I'd consider that modification odd/unwise, unless there's some good (but not obvious to me) justification for doing so.
Simply, it's not sun java, so there's no need or reason to have the sun name there. The java package is from https://jdk-distros.dev.java.net/developer.html, released under the DLJ license. The original binary is jdk-1_5_0_07-distro-linux-i586.bin
Because it's built for Centos, centos is added to the name. There are differences between this java, and the java jdk found at sun, so calling them both sun java would be incorrect and may lead to confusion though the differences are mostly in the jdk packaging and attached license.