I was trying to run three threads at the same time. The threads are called Bubble Sort, Selection Sort, and Insertion Sort. I have created at vector that is suppossed to create random numbers(it does) and a DisplayPanel that is supposed to display the sorted threads in my created frame. I kept getting an error at run time saying " Exception in
thread "Thread-2" java.lang.NullPointerException at Sort$BubbleSort.run(sort.java:193). I don't know whats going on can someone help. Here is my code only for my display panel and BubbleSort() method for reference.