Which are the legacy classes?

What are the Legacy Classes in Java?

• Dictionary.
• Properties.
• HashTable.
• Vector.
• Stack.

What is legacy collections?

The legacy collections use the Enumeration interface for traversing sequences of elements. The Enumeration interface has two methods, hasMoreElements and nextElement. These are entirely analogous to the hasNext and next methods of the Iterator interface. The collection object is more useful.

What U Know About legacy classes in collection hierarchy?

Early versions of java did not include Collections framework. Instead it defined several classes and one interface to store objects. When collection came these classes reengineered to support the Collection interfaces. These old classes are known are legacy classes.

Which of these is the interface of legacy in Java?

Which of these is the interface of legacy is implemented by Hashtable and Dictionary classes? Explanation: Dictionary, Map & Hashtable all implement Map interface hence all of them uses keys to store value in the object. 4.

Is enumeration fail fast?

Fail-fast or Fail-safe : Enumeration is fail-safe in nature. Iterator is fail-fast in nature. It throws ConcurrentModificationException if a Collection is modified while iterating other than its own remove() method.

What is the difference between collection and collections?

The List, Set, and Queue are the main sub-interfaces of the collection interface….Collection vs Collections in Java with Example.

Collection	Collections
It is an interface.	It is a utility class.
It is used to represent a group of individual objects as a single unit.	It defines several utility methods that are used to operate on collection.

What is the interface of legacy?

Enumeration interface defines method to enumerate(obtain one at a time) through collection of objects. This interface is superseded(replaced) by Iterator interface. However, some legacy classes such as Vector and Properties defines several method in which Enumeration interface is used.

What is the use of Legacy class in Java?

Before this version, there was no existence of Collection Framework. Legacy classes and interfaces are used to hold objects in that scenario. This article on Legacy class in Java will let you understand the concept in depth.detail. What are the Legacy classes in Java?

How many legacy interfaces are there in Java?

Apart from the legacy classes, there is only one legacy interface in Java called the Enumeration. The legacy classes in Java are what was called as the ad hoc classes that used to contain values and object groups. Java 2 used to be missing a unified framework called the collections framework before it was introduced in Java 2.

What are the legacy classes in J2SE?

It only defined several classes and interfaces that provide methods for storing objects. When Collections framework were added in J2SE 1.2, the original classes were reengineered to support the collection interface. These classes are also known as Legacy classes. All legacy classes and interface were redesign by JDK 5 to support Generics.

What are legacy classes in JDK 5?

These classes are also known as Legacy classes. All legacy classes and interfaces were redesigned by JDK 5 to support Generics . Dictionary is an abstract class. The main work is to hold the data as the key or value pair. It works in the form of Map Collection.