Javatpoint Logo
Javatpoint Logo

Object Pool Pattern

Mostly, performance is the key issue during the software development and the object creation, which may be a costly step.

Object Pool Pattern says that " to reuse the object that are expensive to create".

Basically, an Object pool is a container which contains a specified amount of objects. When an object is taken from the pool, it is not available in the pool until it is put back. Objects in the pool have a lifecycle: creation, validation and destroy.

A pool helps to manage available resources in a better way. There are many using examples: especially in application servers there are data source pools, thread pools etc.

Advantage of Object Pool design pattern

  • It boosts the performance of the application significantly.
  • It is most effective in a situation where the rate of initializing a class instance is high.
  • It manages the connections and provides a way to reuse and share them.
  • It can also provide the limit for the maximum number of objects that can be created.

Usage:

  • When an application requires objects which are expensive to create. Eg: there is a need of opening too many connections for the database then it takes too longer to create a new one and the database server will be overloaded.
  • When there are several clients who need the same resource at different times.

NOTE: Object pool design pattern is essentially used in Web Container of the server for creating thread pools and data source pools to process the requests.


Example of Object Pool Pattern:

Let's understand the example by the given UML diagram.

UML for Object Pool Pattern

Uml of Object Pool Pattern

Implementation of above UML:

Step 1

Create an ObjectPool class that is used to create the number of objects.

File: ObjectPool.java

Step 2

Create an ExportingProcess class that will be used by ExportingTask class.

File: ExportingProcess.java

Step 3

Create an ExportingTask class that will use ExportingProcess and ObjectPool class.

File: ExportingTask.java

Step 4

Create an ObjectPoolDemo class.

File: ObjectPoolDemo.java

Output

Object Pool Pattern output 1



Please Share

facebook twitter google plus pinterest

Learn Latest Tutorials