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Which design pattern is used in Java IO package?
The Decorator pattern The java.io package provides, among other things, a set of classes for reading input streams. Known as readers, each of those classes has a name that follows the pattern: xxxReader .
What is Decorator design pattern in Java?
The decorator design pattern allows us to dynamically add functionality and behavior to an object without affecting the behavior of other existing objects within the same class. The decorator design pattern is a structural pattern, which provides a wrapper to the existing class.
Does Decorator design pattern modify all instances of a class?
The decorator pattern is an alternative to subclassing. Subclassing adds behavior at compile time, and the change affects all instances of the original class; decorating can provide new behavior at run-time for selected objects. This would mean that a new class would have to be made for every possible combination.
What is util package in java?
util Package. It contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes (a string tokenizer, a random-number generator, and a bit array).
What is the io package in java?
The Java I/O package, a.k.a. java.io, provides a set of input streams and a set of output streams used to read and write data to files or other input and output sources. There are three categories of classes in java.io: input streams, output streams and everything else.
What is a Java facade?
Facade is a structural design pattern that provides a simplified (but limited) interface to a complex system of classes, library or framework. While Facade decreases the overall complexity of the application, it also helps to move unwanted dependencies to one place.
When to use the decorator pattern in Java?
The decorator pattern is used in java.io classes when you manipulated input/output streams (and the same applies for readers and writers). inputstream, bytearrayinputstream, stringbuilderinputstreams and so on are based elements.
How is decorator pattern different from static inheritance?
In other words, The Decorator Pattern uses composition instead of inheritance to extend the functionality of an object at runtime. The Decorator Pattern is also known as Wrapper. It provides greater flexibility than static inheritance. It enhances the extensibility of the object, because changes are made by coding new classes.
What are the disadvantages of decorator design pattern?
The disadvantage of decorator design pattern is that it uses plenty of similar kind of objects (decorators) Create an interface. Create concrete classes implementing the same interface.
Which is an example of a decorator pattern?
Such a decorated stream can be used exactly the same way as a “regular” input/output stream, with compression/decompression performed totally transparently. The decorator pattern is used to add functionality to existing objects such as a class defined in a library. You can then “decorate” it to fit your needs.