Difference between org.junit.Test and junit.framework.Test packages
The junit.framework.Test package is the legacy namespace used by older projects that used JUnit v3 which was for versions of Java that did not support annotations.
The org.junit.Test package is the new namespace used by JUnit v4 which requires Java v1.5 or later for its annotations. Use JUnit 4 and the latest Java if possible because the new annotations are vastly superior.
The current distributions of JUnit 4 include a copy of the old namespace to allow easy migration; however you should avoid using JUnit3 form for new tests and convert old tests to JUnit 4 as you can.
In JUnit 4 both packages are included in the library jar for migrations purposes but you should use org.junit.Test for new code and those test do not need to extend TestCase.
You can see a basic example of Junit4 test case.