NullPointerException's Flight Booking System Project

How to compile and run

To compile on the command line, change to the src/ directory and use the following command:

javac -cp ../lib/json-simple-1.1.1.jar *.java

To run, use one of the following commands:

Linux:

java -cp ../lib/json-simple-1.1.1.jar: MainDriver

Windows:

java -cp "../lib/json-simple-1.1.1.jar;" MainDriver