Real-Life Example of the Visitor Design Pattern
Imagine you own a zoo with different types of animals: lions, monkeys, and elephants. Now, you want to perform various tasks on these animals, such as feeding, cleaning, and monitoring their health.
Instead of modifying each animal’s class to accommodate these tasks, you can implement the Visitor pattern:
- The zookeepers represent the visitors.
- The animals represent the elements.
- Each type of animal (lion, monkey, elephant) has specific tasks associated with it.
Here’s how it works:
- Each animal has an accept method that allows a zookeeper to visit it.
- When a zookeeper visits an animal, the animal invokes the appropriate method on the zookeeper, depending on its type.
- For example, if a zookeeper wants to feed a lion, the lion would invoke the feed method on the zookeeper.
- Similarly, if a zookeeper wants to clean an elephant enclosure, the elephant would invoke the clean method on the zookeeper.
By using the Visitor pattern in this scenario, you can add new types of tasks or visitors to the zoo without changing the existing animal classes. This makes it easier to manage and extend the zoo’s functionality over time.
Visitor Design Pattern in Java
The Visitor Design Pattern is a behavioral design pattern that allows you to separate algorithms or operations from the objects on which they operate. It enables you to add new operations to objects without modifying their structure.
Important Topics for Visitor Design Pattern in Java
- What is the Visitor Design Pattern?
- Real-Life Example of the Visitor Design Pattern
- Key Components in the Visitor Design Pattern
- UML Class Diagram of the Visitor Design Pattern
- Example of the Visitor Design Pattern
- Use Cases of the Visitor Design Pattern
- Advantages of the Visitor Design Pattern
- Disadvantage of the Visitor Design Pattern