JAVACOLLECTIONSFRAMEWORK.PDF

JAVA COLL CT IONS FRAM WORK JAVA COLL CT IONS FRAM WORK http://www.tutorialspoint .com/java/java_collections.htm Copy right © Prior to Java 2, Java provided ad hoc classes such as Dictionary, Vector, Stack, and Properties to store and manipulate groups of objects. A lthough these classes were quite useful, they lacked a central, unifying theme. T hus, the way that you used Vector was different from the way that you used Properties. T he collections framework was designed to meet several goals. T he framework had to be high-performance. T he implementations for the fundamental collections dynamicarrays, linkedlists, trees, andhashtables are highly efficient. T he framework had to allow different types of collections to work in a similar manner and with a high degree of interoperability. xtending and/or adapting a collection had to be easy. Towards this end, the entire collections framework is designed around a set of standard interfaces. Several standard implementations such as LinkedList, HashSet, and T reeSet, of these interfaces are provided that you may use as-is and you may also implement your own collection, if you choose. A collections framework is a unified architecture for representing and manipulating collections. A ll collections frameworks contain the following: Interfaces: T hese are abstract data types that represent collections. Interfaces allow collections to be manipulated independently of the details of their representation. In object- oriented languages, interfaces generally form a hierarchy. Implementations, i.e., Classes: T hese are the concrete implementations of the collection interfaces. In essence, they are reusable data structures. Al orithms: T hese are the methods that perform useful computations, such as searching and sorting, on objec