Much of the java.net package has been added to the code coverage reports (they will be online as soon as the autobuilder gets to it).
As a rule, if a package you're interested in is not covered in the reports, that does not mean it will never be covered. I'm working on expanding the reports to cover more packages. Check back often or send me a request. The reports are at http://builder.classpath.org/~cpdev/coverage/ --Tony