java.lang.NullPointerException error message

Question

ImgSet[0] = new ImageIcon("bandeira-portugal.png",
                            "Portugal");
ImgSet[1] = new ImageIcon("south_korea-32.png",
                            "South_Korea");
ImgSet[2] = new ImageIcon("China-icon.png",
                            "China");
ImgSet[3] = new ImageIcon("Japan.png",
                            "Japan");

This is my code for the image icons. I am getting the error message "java.lang.NullPointerException"! Can you please tell me how to fix it? My picture files are in the program folder!

Yes I did set the variable ImgSet if that's got anything to do with it.

private Icon[] ImgSet;

ImgSet have the 3 images.so null pointer exception will be thrown — suresh manda, Nov 20 '14 at 12:56

score 3 · Accepted Answer · answered Nov 20 '14 at 12:56

Initialize your array first. Thats all:)

private Icon[] ImgSet = new Icon[4];

Remember that you cannot change arrays length, after you initialize it, so select a good size, in this example it is 4. If your collection is dynamic (you will add more elements, depending on runtime), change it to list, or set. Remember that arrays are fast, but their size is not editable.

score 0 · Answer 2 · answered Nov 20 '14 at 13:01

0

You're just declaring ImgSet variable by doing:

private Icon[] ImgSet;

To initialize you should do something like:

private Icon[] ImgSet = new Icon[n];

Where n should be an initialized int or Integer.

You may way to use something like ArrayList or LinkedList instances from the java.util package.

answered Nov 20 '14 at 13:01

diegoaguilar

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Welcome, glad you achieved it. New to Java uh? – diegoaguilar Nov 21 '14 at 00:56

score 0 · Answer 3 · answered Nov 20 '14 at 13:04

Maybe you forget to initialize your array before.

Try this

ImageIcon[] ImgSet = 
{
   new ImageIcon("bandeira-portugal.png", "Portugal"),
   new ImageIcon("south_korea-32.png", "South_Korea"),
   new ImageIcon("China-icon.png", "China"),
   new ImageIcon("Japan.png","Japan")
};

Doubts: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html

java.lang.NullPointerException error message

3 Answers3