A data structure is encapsulation of data and relevant operations. It is referred to as an Abstract Data Type (ADT), signifying that the actual implementation is left open, subject to satisfying the intended meaning of the operations. For the most part the exact data representation is not presented; rather, all access to the data is through the operations.
The Java class is a perfect model for an ADT. In addition to the encapsulation with accessibility via operations only, the presentation of operations are in the modern object-oriented fashion...