ElectronicTollGates (UML Diagram)
ElectronicTollGates is a simulation of an Electronic Toll Collection System. Customers are assigned to random vehicles and then driven through tollgates on random highways. Each customer can own multiple vehicles, which are randomly determined at runtime. The Visitor Pattern is used to calculate individual toll costs and print invoices to system.out. The number of customers and the number of months to simulate can be easily changed at the beginning or during the simulation.
List of design patterns used:
- Visitor Pattern
- Factory Pattern
- Strategy Pattern
- Singleton Pattern
The Visitor Pattern is used to calculate toll costs for each customer. A TollCostVisitor visits the EtcSystem, calculates costs, and then displays the individual invoices to System.out.
The Factory Method is used to create a variety of random vehicles. It is used in combination with the Strategy Pattern to allow a variety of vehicles to be randomly created for the simulation.
The Strategy Pattern is used to encapsulate a family of vehicle algorithms. By exploiting polymorphism, the EtcSystem simulation can be initialized with random vehicle types. In addition, the Strategy Pattern would allow customer vehicles to be dynamically changed during the simulation if so desired.
The Singleton Pattern is used to create a single unique instance of the EtcSystem. Lazy instantiation is used to create an instance if it does not exist. The getInstance() method is defined as a synchronized static method to fix the multithreading issue by forcing every thread to wait its turn before it can enter the method. Therefore, no two threads may enter the method at the same time.
1. Clone this repository
2. mvn clean compile test
1.0.0
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Copyright (c) 2019 Vincent Pasquariello
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