what is difference between Oops concepts in Perl and Java in terms of implementation.

Perl's builtin object model is pretty fundamental. It allows for arbitrary models to be used.

Encapsulation

Perl doesn't define how to implement attributes, so encapsulation is up to the specific model used.

In most cases, the attributes are easily accessible from the outside, but encapsulation is still very strong. It's just that it's enforced by policy, not by technical means.

Inheritance

Single and multiple. Two different method resolution order for multiple inheritance.

Polymorhpism

Yes. All methods are virtual, basically.