Template Design Pattern

Template Design Pattern

If the framework needs to own and control the algorithm but also call the subclasses as and when needed, then use “Template Design Pattern”. Works on the Hollywood principle of “Don’t call me, I will call you”.

                 

1.     Create a “Template Method” that defines a skeleton of an algorithm in an operation. Template method defers some steps to the sub-classes. Additionally it lets subclass redefine a certain step in processing using “Hooks”.

2.     Hooks are methods that don’t do anything or have a default behavior. But subclass may override that behavior.

3.     To prevent subclasses from changing the algorithm, the template method is made final.
It is also know as the algorithm method.

4.     Factory method is a specialization of Template Method.

5.     Subclasses decide how to implement steps in an algorithm.

6.     All duplicate codes are put into the superclass so that all subclasses can share it.

An example can be how Tea & Coffee are made.

Template Pattern in java Arrays.class

Code link : https://github.com/sksumit1/DesignPatterns