Null pointer with ArrayList?

[Paradox68]

Declaring the ArrayList

	public ArrayList<Integer> allTimes;

One function for array:

				if (!allTimes.isEmpty() && allTimes != null) {
					allTimes.clear();
				}

Second function:

							tripE = System.currentTimeMillis() - tripS;
							if (allTimes != null) {
								allTimes.add((int)tripE);
							}

Calculating average times.

		int averageTime = 0;
		if (allTimes.toArray().length > 3) {
			int total = 0;
			for (int i = 0; i < allTimes.toArray().length; i++) {
				total += allTimes.get(i).intValue();
			}
			averageTime = (total / allTimes.toArray().length);
		}

I don't know if it's the only one but the Nullpointer is thrown on allTimes.clear();

Edited October 14, 2015 by Paradox68

[Precise]

Declaring the ArrayList

	public ArrayList<Integer> allTimes;

One function for array:

				if (!allTimes.isEmpty() && allTimes != null) {
					allTimes.clear();
				}

Second function:

							tripE = System.currentTimeMillis() - tripS;
							if (allTimes != null) {
								allTimes.add((int)tripE);
							}

Calculating average times.

		int averageTime = 0;
		if (allTimes.toArray().length > 3) {
			int total = 0;
			for (int i = 0; i < allTimes.toArray().length; i++) {
				total += allTimes.get(i).intValue();
			}
			averageTime = (total / allTimes.toArray().length);
		}

I don't know if it's the only one but the Nullpointer is thrown on allTimes.clear();

 

should null check before checking if isnt empty

[Paradox68]

should null check before checking if isnt empty

 

 

So the null check works, but why is it throwing a null? Now the code just isn't being called.

[Ziy]

Post where the lines you update the allTimes reference. You are assigning it null somewhere

[Czar]

public ArrayList<Integer> allTimes = new ArrayList<Integer>();

 

otherwise just make sure you actually set it (if you are setting it to null)

[Mysteryy]

So the null check works, but why is it throwing a null? Now the code just isn't being called.

 

 

You need to initialize the array list. Right now, you are declaring an arraylist but not initializing it.

 

ArrayList blah = new ArrayList

[Paradox68]

Thanks guys, I forgot to post on the thread when I corrected it but Czar was right. I had to assign an initial value of an ArrayList.