Up to Java 1.4 it was possible to import classes from the default package, just by writing: import ClassName;. This feature was removed in Java 5. It's not a good idea to put classes in the default package - you should always put your classes in a package.
It is not needed to import classes from default package in java because all the classes like System, String, Integer, Array, Float,etc are from java.lang package which is considered to be default imported package in a java program.
Amol Nakhwa. wrote:It is not needed to import classes from default package in java
You misunderstand what the "default package" is. What you describe refers to the fact that each source file has an implicit "import java.lang.*" statement, but that's different from the default package - Jesper's answer is spot on.