Why isn't javax.activation in the java source zip?

elsewhere eg.[1] it is explained that when you install the java source in ubuntu, it is put here: /usr/lib/jvm/java-6-sun-1.6.0.20/src.zip

The problem is that it does not contain the javax.activation pac开发者_StackOverflow中文版kage and thus not classes like: javax.activation.DataSource Why isn't it there? Must I download the source manually to get that?

[1] Where to find Java JDK Source Code?

The package is javax.activation, not java.activation - and typically, source code for javax... packages isn't included.

The various components of javax use different licenses, so this could be the reason. I've taken the liberty to ask your platform of choice's maintainers here.

I will update this answer as soon as I get an answer.