Needs Java 12 installed in the system that is running the program.

• Open Command Prompt in the main directory - Go to individual-project-NishaMDev. Run below commands in the sequence to install the maven project –

  mvn compile

  mvn clean install

• Run the following command in the command prompt:

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="<Path to Input Data> <Path to Flight details to populate DB>"

• For Example:

  1. For Input File 1: -

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="InputFile.csv flights.csv"

  2. For Input File 2: -

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="InputFile1.csv flights.csv"

  3. For Input File 3: -

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="InputFile2.csv flights.csv"

  4. For Input File 4: -

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="InputFile3.csv flights.csv"

  5. For Input File 5: -

  mvn exec:java -Dexec.mainClass=test.RunClient -Dexec.args="InputFile4.csv flights.csv"

• Output files will be created in the directory as the files provided as arguments to run the command.

We will build a flight booking application using at least three design patterns. The application should maintain an internal, static database (inventory of flight details) (this may be developed using HashMap’s and/or other built-in Java Data structures). This means once we re-run the program, the changes to the data would not persist. We will provide the data that has to be maintained. The data will contain the following tables and fields:

Table 1: Flights

• Category (Economy, Premium Economy, Business)
• Flight number
• The available Seats of each category
• Price of each seat
• Arrival City
• Departure City

• Singleton
• Factory
• Chains of Responsibility

• It is creational design pattern that lets you ensure that a class has only one instance, while providing the global access point to this instance.

• This pattern is used to build the database for the application. Only the Database class is used as part of this pattern.

• Whenever an instance of the database is needed, the getInstance() method is called so that only one instance of the object can be reused.

  

• It is a creational design pattern that provides an interface for creating objects in a superclass but allows subclasses to alter the type of objects that will be created.

• We have used this pattern to output when an order is processed. The following files are as part of this pattern implementation:

• Interface OutputFile
• Class CheckoutFile
• Class ErrorFile

• When the respective concrete handler figures out the output should be a checkout file or error file, we will create an object of OutputFile. The FileReader class is used to read and create files in the application.

  

• It is a behavioral design pattern that lets you pass requests along a chain of handlers. Upon receiving a request, each handler decided either to process the request or to pass it to the next handler in the chain.

• We have used this design pattern to determine if the order can be processed correctly or not. The following files are used in this pattern:

  • Interface ValidationHandler
  • Class FlightPresenceValidation
  • Class FlightSeatValidation.
  • Class CardValidation

• Before we verify the order can be processed or not, ValidationHandler object is created and will be passed on from one Handler to another using the same.