NullPointerException Issue please assist

Question

Hey guys I'm a beginner (sort off) in java and i'm having some trouble. I'm trying to get the date I set in the Budget class with a variable in the Finances class but I keep getting a NullPointerException.

I'm trying to use the dueDate variable in the finances class but the logCat keeps stating that it's a null object reference even after I've instantiated it.

public class Budget {
    private Date mDate = new Date();
    public static double budgetAmount;

    private static Budget instance = new Budget();
    private Budget(){

    }

    public double getBudget(){
        return budgetAmount;
    }

    public void setBudget(double budget){
        budgetAmount = budget;
    }

    public static Budget getInstance(){
        return instance;
    }


    public Date getDate() {
        return mDate;
    }

    public void setDate(Date date) {
        mDate = date;
    }

}

Here is the Financial Class

public class Finances extends Activity{
    int amtFood; int amtCar; int amtGas; int amtTvBill; int amtInBill;
    int amtTronics; int amtWear; int amtLight; int amtWater; int amtOthers;

    Date nowDate;
    Date dueDate = new Date();

    double MainAmount = Budget.budgetAmount;
    static int SpentAmount;

    Budget budgetDate;

    public Finances(){
        HashMap<String,Integer> amtAdd = ExpenditureLab.get(this).getExpendMap();
        int food= amtAdd.get("Groceries/Food");
        int car = amtAdd.get("Car servicing");
        int gas = amtAdd.get("Gas Money");
        int tvBill = amtAdd.get("Television Bill");
        int inBill = amtAdd.get("Internet Bill");
        int tronics = amtAdd.get("Electronics");
        int wear = amtAdd.get("Clothes/Wearables");
        int light = amtAdd.get("Light Bill");
        int water = amtAdd.get("Water Bill");
        int others = amtAdd.get("Others");



        dueDate = budgetDate.getDate();
    }

    public void addSpent(int amt){
        SpentAmount += amt;
    }

}

Activities should not define a constructor, better read http://developer.android.com/reference/android/app/Activity.html — Diego Torres Milano, Mar 27 '15 at 03:53
getDate should static method so is mDate in your budget class — Pankaj Nimgade, Mar 27 '15 at 03:57
Your question may already have an answer here: [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Pokechu22, Mar 29 '15 at 19:46

Danoram · Accepted Answer · 2015-03-27T08:04:11.610

budgetDate is never initailized.

Budget budgetDate; #=> this is null

and then you try call getDate() on the null object.

dueDate = budgetDate.getDate(); #=> causing your nullPointerException?

Therefore you need to instantiate your budgetDate object first.

Budget budgetDate = new Budget();

and then set the mDate object

budgetDate.setDate(someDate); #=> someDate is a Date object

before calling

dueDate = budgetDate.getDate();

score 1 · Answer 2 · answered Mar 27 '15 at 04:19

1

Yes budgetDate is not initialized, leading to null pointer exception. Also do not use constructor in an Activity, you can have all your initializations in the onCreate method of your Activity.

answered Mar 27 '15 at 04:19

Chamu

194
5

score 0 · Answer 3 · answered Mar 27 '15 at 03:57

0

dueDate isn't the null object, you're setting it to budgetDate.getDate(), and budgetDate has not been instantiated yet.

answered Mar 27 '15 at 03:57

Rich

36,270
31
115
154

Trần Đức Tâm · Answer 4 · 2015-03-27T04:21:50.493

I don't see the place you assign value to budgetDate (is never initailized). It's null pointer exception when you call dueDate = budgetDate.getDate();

Solution: Place budgetDate = new Budget() before dueDate = budgetDate.getDate(); like that:

@Override
public void onCreate(Bundle bundle) {
    HashMap<String,Integer> amtAdd = ExpenditureLab.get(this).getExpendMap();
    int food= amtAdd.get("Groceries/Food");
    int car = amtAdd.get("Car servicing");
    int gas = amtAdd.get("Gas Money");
    int tvBill = amtAdd.get("Television Bill");
    int inBill = amtAdd.get("Internet Bill");
    int tronics = amtAdd.get("Electronics");
    int wear = amtAdd.get("Clothes/Wearables");
    int light = amtAdd.get("Light Bill");
    int water = amtAdd.get("Water Bill");
    int others = amtAdd.get("Others");

    budgetDate = new Budget();
    dueDate = budgetDate.getDate();
}

NullPointerException Issue please assist

4 Answers4