Question

I need to write a Java Programm based on the follwoing facts:

A company that operates regional trains wants to model the utilization of their trains. For this she has created the following UML class diagram.

Train

-capacity:int -numberPassengers:int

+Train(capacity:int) +getcapacity():int +getNumberPassengers();int +setNumberPassengers(numbersPassengers:int):void

The exercise i need help with is as follows:

Write a Java class train for the given class diagram and implement all the methods. The number of passengers of new instances should be 0. The method setNumberPassengers should set the attribute numberPassengers

• to the value 0, if the value of the parameter passenger-number is less than 0,

• to the value of the attribute capacitance, if the value of the parameter passenger-parameter is greater than this value,

• and otherwise to the Value of parameter numberPassage

b) Write a Java class train simulator using a main method that 1

• creates a train with capacity 100,

• simulates the change in the number of passengers for stops 1, ..., 40, whereby

• when arriving at stop number i, a random number of passengers first disembark (equally distributed, maximum 40 persons),

• after that, a random number of passengers descend (equally distributed, maximum 40),

• the number of passengers, when the train leaves the i-th stop, on the console outputs.

If more people want to get off than on the train, or more people board than the train allows because of its capacity, the setter for countless passengers should take care of it. The random number generation does not need to be adjusted. Notes: For random numbers, you should use the Math.random method

Answer 1

Hi,

Please find the code below for the problem statement. I have added the snapshot of the output below.

import java.lang.Math;
class Train{
  
private int capacity;
private int numberPassengers;
  
public Train(int capacity){
this.capacity = capacity;
setNumberPassengers(0);
}
  
public int getcapacity(){
return capacity;
}
  
public int getNumberPassengers(){
return numberPassengers;
}
  
public void setNumberPassengers(int numbersPassengers){
if(numbersPassengers<0){
this.numberPassengers = 0;
}
else if(numbersPassengers>capacity){
this.numberPassengers = capacity;
}
else{
this.numberPassengers = numbersPassengers;
}
}
}

public class TrainSimulator{
  
public static void main(String []args){
Train train = new Train(100);
int MAX_PPL = 40;
int tmp = 0;
for(int stop = 1; stop <= 40 ; stop++){
// passengers getting out
tmp = train.getNumberPassengers() - (int)(Math.random() * (MAX_PPL + 1));
train.setNumberPassengers(tmp);
// passengers getting in
tmp = train.getNumberPassengers() + (int)(Math.random() * (MAX_PPL + 1));
train.setNumberPassengers(tmp);
System.out.println("Number of passenger in Train while leaving station "+stop+" is "+train.getNumberPassengers());
}
  
  
}
  
}

OUTPUT:

Number of passenger in Train while leaving station 1 is 18 Number of passenger in Train while leaving station 2 is 24 Number of passenger in Train while leaving station 3 is 28 Number of passenger in Train while leaving station 4 is 11 Number of passenger in Train while leaving station 5 is 32 Number of passenger in Train while leaving station 6 is 33 Number of passenger in Train while leaving station 7 is 24 Number of passenger in Train while leaving station 8 is 17 Number of passenger in Train while leaving station 9 is 8 Number of passenger in Train while leaving station 10 is 5 Number of passenger in Train while leaving station 11 is 22 Number of passenger in Train while leaving station 12 is 17 Number of passenger in Train while leaving station 13 is 2 Number of passenger in Train while leaving station 14 is 18 Number of passenger in Train while leaving station 15 is 39 Number of passenger in Train while leaving station 16 is 35 Number of passenger in Train while leaving station 17 is 35 Number of passenger in Train while leaving station 18 is 42 Number of passenger in Train while leaving station 19 is 47 Number of passenger in Train while leaving station 20 is 10 Number of passenger in Train while leaving station 21 is 22 Number of passenger in Train while leaving station 22 is 13 Number of passenger in Train while leaving station 23 is 1 Number of passenger in Train while leaving station 24 is 7 Number of passenger in Train while leaving station 25 is 12 Number of passenger in Train while leaving station 26 is 15 Number of passenger in Train while leaving station 27 is 52 Number of passenger in Train while leaving station 28 is Number of passenger in Train while leaving station 29 is Number of passenger in Train while leaving station 30 is 45 Number of passenger in Train while leaving station 31 is Number of passenger in Train while leaving station 32 is 42 Number of passenger in Train while leaving station 33 is 47 Number of passenger in Train while leaving station 34 is 46 Number of passenger in Train while leaving station 35 is 71 Number of passenger in Train while leaving station 36 is 73 Number of passenger in Train while leaving station 37 is 74 Number of passenger in Train while leaving station 38 is 83 Number of passenger in Train while leaving station 39 is 59 Number of passenger in Train while leaving station 40 is 76

I hope it helps.

Please revert back to me in case of any query and give a thumbs up if you like the solution.

Have a great day :)