Java Patterns

Canonical and GoF patterns are almost similar in characteristics. Canonical form places greater importance on explicit forces and resolutions whereas in GoF format a solution is broken into different sections and it also uses design diagrams with sample code.

Abstract factory pattern is used to create instances of abstract classes from a matched set of concrete sub classes. This pattern allows a developer to use various complex technologies such as windowing systems with similar characteristics and functionality. It basically createsabstract classes.

There are very few patterns which are used by developers and programmers they are Gang of four patterns, Canonical form or pattern and Alexandrian form. Some of the elements present in patterns are Problem, name, aliases, context, forces, solution, examples, resulting context, rationale, related patterns, uses, etc.

Patterns are used to detail about a problem and its solution but is should not be restricted at that point it should also include about the difficulty of the problem, solution addressing all the concerns, constraints of all sorts, etc. It should include everything which revolves around the Generative solution to a problem.

Java patterns are used in these scenarios they are: -

► Giving solutions to recurring problems.

► Practical solutions to real world problems rather than theoretical solutions.

► It can also be used to document real world solutions to a particular problem.

► It can work really well for given concern or trade offs.

Java patterns are used for many purposes some of them are: -

1) It describes about the problem and its solution in detail.

2) Solving a common problem becomes easy because of predefined solutions from other programmers and developers.

3) They describe practical problems rather than theoretical problems they are very useful in the real world.

4) Time utilization and productivity is greater due to the usage of Java patterns.

Patterns are very useful programming technique to a programmer. They tend to make solutions easier by creating a design pattern which can be used by a different developer other than the creator. They function as problem solving documentation. Solutions offered by Java Patterns are very practical rather than theoretical.

A design pattern which obviously appears, but is an ineffective or far from optimal in practice. There must be atleast two key elements for formally distinguishing an actual anti-pattern from a single bad idea, bad practice or bad habit.

There are various different patterns and they can be divided into these patterns they are: -

► Fundamental design patterns

► Creational patterns

► Partitioning patterns

► Structural patterns

► Behavioral patterns

► Concurrency patterns

Delegation, Interface, Immutable, Proxy and marker interface are some of the sub divisions present in Fundamental interface.