Unable To Pass Data Using putExtra/getString Methods from one Java class to another class

Question

I have two classes;

1. ProgramAdapter.java
2. buy_ticket.java

I want to pass data from the ProgramAdapter class to the Buy_Ticket class. I am getting the error below:

"Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference at com.smartsoft.travelmate.buy_ticket.onCreate(buy_ticket.java:35)"

Why am I getting this error and how I can get past this problem? My issue could be from the putExtra method statement or the getString method statement but I can't see the issue.

Error Source: Buy_Ticket.class line 35: String operatorName=getIntent().getExtras().getString("operator");//Get operator name

Error Message Log:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.smartsoft.travelmate, PID: 9643
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.smartsoft.travelmate/com.smartsoft.travelmate.buy_ticket}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference

ProgramAdapter

public class ProgramAdapter extends ArrayAdapter<String> {
    Context context;
    int[] images;
    String[] operatorName;
    String[] busRegistration;
    String[] trip;
    String[] ticketPrice;
    String[] departureDates;
    String[] departureTimes;
    String fetchedOperator;


    public ProgramAdapter(available_buses context, int[] images,String[] operatorName, String[] 
    busRegistration,String[] trip,String[] ticketPrice,String[] departureDates, String[] 
    departureTimes) {
        super(context, R.layout.bus_operater,R.id.txtOperator,operatorName);
        this.context = context;
        this.images = images;
        this.operatorName = operatorName;
        this.busRegistration = busRegistration;
        this.trip=trip;
        this.ticketPrice = ticketPrice;
        this.departureDates = departureDates;
        this.departureTimes = departureTimes;

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View singleItem=convertView;
        ProgramViewHolder holder = null;

        if (singleItem==null){
            LayoutInflater layoutinflator = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            singleItem=layoutinflator.inflate(R.layout.bus_operater,parent,false);
            holder = new ProgramViewHolder(singleItem);
            singleItem.setTag(holder);
        }else {
            holder = (ProgramViewHolder) singleItem.getTag();
        }
        holder.itemImage.setImageResource(images [position]);
        holder.operatorName.setText(operatorName [position]);
        holder.busRegistration.setText("(" + busRegistration [position] + ")");
        holder.trip.setText("Trip: " + trip [position]);
        holder.departureDates.setText("Departure Date: " + departureDates [position]);
        holder.departureTimes.setText("Departure Time: " + departureTimes [position]);
        holder.ticketPrice.setText("Ticket Price: " + ticketPrice [position]);

        singleItem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //Toast.makeText(getContext(),"You tapped: " + operatorName [position],Toast.LENGTH_SHORT).show();
                Intent i = new Intent(context, buy_ticket.class);
                context.startActivity(i);
                fetchedOperator=operatorName[position].toString();
                //Toast.makeText(getContext(), fetchedOperator, Toast.LENGTH_SHORT).show();//Test code
                i.putExtra("operator",fetchedOperator);
            }
        });
        return singleItem;
    }
}

buy_ticket

public class buy_ticket extends AppCompatActivity {
Button bBuyTicket;//Button Buy Ticket
TextView tvSTDTicketPrice,tvGrandTicketCost;//Declare UI views/controls

int seatCapacity=60;
double ticketQuantity;//Declare integer variables
double grandTicketsCost,ticketPrice;//Declare float variables

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_buy_ticket);

        String operatorName=getIntent().getExtras().getString("operator");//Get operator name

        TextView tvOperatorName=(TextView)findViewById(R.id.txtOperator);
        //tvOperatorName.setText(operatorName);

        Spinner sTQuantity = findViewById(R.id.spinTicketQuantity);//Declare ticket quantity object/spinner

        List<String> totalPassengers=new ArrayList<>();//Define arraylist object

        for (int i=1;i<=seatCapacity;i++)
        {
            totalPassengers.add(String.valueOf(i));//Populate spinner with integer numbers according to max bus seating capacity
        }

        ArrayAdapter<String> tickets_adapter;
        tickets_adapter= new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, totalPassengers);
        tickets_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sTQuantity.setAdapter(tickets_adapter);

        bBuyTicket=findViewById(R.id.btnBuyTicket); //Cast button to variable buyTicket
        tvSTDTicketPrice=findViewById(R.id.txtSTDTicketPrice);//Cast textview to variable tvSTDTicketPrice
        tvGrandTicketCost=findViewById(R.id.txtTotalTicketCost);

        sTQuantity.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                DecimalFormat numberFormatter=new DecimalFormat("#,###.##");
                //Get ticket price from string
                String fetchedPrice=tvSTDTicketPrice.getText().toString().substring(4);//Get the standard ticket price
                ticketPrice=Double.parseDouble(fetchedPrice);//Convert ticket price to float
                ticketQuantity=Double.parseDouble(sTQuantity.getSelectedItem().toString());//Get the desired number of tickets to be purchased
                grandTicketsCost=Double.valueOf(ticketPrice*ticketQuantity);//Calculate the total cost of the tickets
                tvGrandTicketCost.setText("ZMW " + String.valueOf(numberFormatter.format(grandTicketsCost)));//Display the total cost if the tickets
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
        //Get number of tickets required

        //Buy Ticket Code
        bBuyTicket.setOnClickListener(view -> {

        });

    }
}