Train between two stations

A train runs between two stations "A" and "B". According to the timetable, the train stays for a certain time at each station and moves for a certain time to the other station. It transfers passengers who are traveling to either station (randomly generated). It is permitted to board a maximum of N passengers. Model the situation in Java.

Resource - monitor. The monitor summarizes the situation through private variables such as: where the train is, in which direction it is moving, the number of passengers on board, how many passengers are waiting at the two stations, the maximum number of passengers on the train . It provides synchronized public methods for modifying variables.

onA, onB - The train stopped at station A or B
passAB,passBA - number of passengers on the train;
passMax -Maximum number of passengers on the train;
leaveA(), leaveB(), arriveA(), arriveB() - Departure or arrival from (to) the station;
taketA(), taketB(), leavetA(), leavetB(), - travelers get on or off the train.

public class Monitor {
    private boolean onA, onB;
    private int passAB,passBA, passMax;
    public Monitor(int passMax ){
        onA=true;
        System.out.println("Train on A");
        onB = false;
        passAB=passBA=0;
        this.passMax=passMax;
    }
    public synchronized void leaveA(){
        onA=false;
        System.out.println("\t\t\t\tTrain travelling A ->B");
    }
    public synchronized void arriveB(){
        System.out.println("\t\t\t\tTrain arrive B");
        onB=true;
        notifyAll();
    }
    public synchronized void leaveB(){
        onB = false;
        System.out.println("\t\t\t\tTrain travelling B ->A");
    }
    public synchronized void arriveA(){
        System.out.println("\t\t\t\tTrain arrive A");
        onA=true;
        notifyAll();
    }
    public synchronized void taketA(){
        while(!onA||((passAB+passBA)>=passMax)){
            System.out.println("\t\t"+Thread.currentThread().getName()+" waiting train");
            try{     wait();   }
            catch(InterruptedException e){
                System.err.println(e);
            }
        }
        System.out.print(Thread.currentThread().getName()+" get the train;");
        passAB++;
        if(passAB+passBA >= passMax) System.out.print(" train is full");
        System.out.println("\t"+passAB+" passengers in the train traveling A-> B");
    }
    public synchronized void taketB(){
        while(!onB||((passAB+passBA)>=passMax)){
            System.out.println("\t\t"+Thread.currentThread().getName()+" waiting train");
            try{     wait();   }
            catch(InterruptedException e){
                System.err.println(e);
            }
        }
        System.out.print(Thread.currentThread().getName()+" get the train;");
        passBA++;
        if(passAB+passBA >= passMax) System.out.print(" train is full");
        System.out.println("\t"+passBA+" passengers in the train traveling B-> A");
    }
    public synchronized void leavetA(){
        while(!onA){
            //System.out.println("\t"+Thread.currentThread().getName()+" traveling in the train");
            try{     wait();   }
            catch(InterruptedException e){
                System.err.println(e);
            }
        }
        System.out.print(Thread.currentThread().getName()+" leaving the train and going home; ");
        if(passBA>0)passBA--;
        System.out.println("\t"+passBA+" passengers B-> A still in the train");
        notifyAll();
    }
    public synchronized void leavetB(){
        while(!onB){
            //System.out.println(Thread.currentThread().getName()+" traveling in the train");
            try{     wait();   }
            catch(InterruptedException e){
                System.err.println(e);
            }
        }
        System.out.print(Thread.currentThread().getName()+" leaving the train and going home; ");
        if(passAB>0)passAB--;
        System.out.println("\t"+passAB+" passengers A-> B still in the train");
        notifyAll();
    }
}

Train - thread
The train goes 3 times from station A to station B and back.

public class Train extends Thread{
    Monitor mt;
    public Train(Monitor mt){
        this.mt=mt;
    }
    public void run(){
        for(int i=0;i<3;i++){
            try{
                sleep(1000);
            }
            catch(InterruptedException e){}
            mt.leaveA();
            try{
                sleep(2000);
            }
            catch(InterruptedException e){}
            mt.arriveB();
            try{
                sleep(1000);
            }
            catch(InterruptedException e){}
            mt.leaveB();
            try{
                sleep(2000);
            }
            catch(InterruptedException e){}
            mt.arriveA();
        }
    }
}

Passengers - thread
aToB - direction of travel is introduced the name of the passenger.

public class Pass extends Thread{
    boolean aToB;
    static int num=1;
    Monitor mt;
    String name;
    Pass(Monitor mt,boolean aToB){
        name = "pass"+num++ +(aToB?"(A to B)":"(B to A)");
        super.setName(name);
        this.mt=mt;
        this.aToB = aToB;
    }
    public void run(){
        if(aToB){
            mt.taketA();
            mt.leavetB();
        }
        else{
            mt.taketB();
            mt.leavetA();
        }
    }
}

Model Startup
20 randomly generated passengers;
5 passengers maximum on the train.

public class Circ {
    public static void main(String arg[]){
        Monitor mt = new Monitor(5);
        Train train = new Train(mt);
        train.start();
        for(int i=0;i<20;i++){
            (new Pass(mt,Math.random()>0.5?true:false)).start();
        }
    }
}

Problem: In this model if the time to stay at a train station is too short, the train starts without waiting for all the passengers to get off!