My whileloop keeps on erroring while i'm trying to create an insert sort

Question

I get this error when I try to run my code. Compiling works fine:
ArrayIndexOutOfBoundsException: 31
at ReadData.sort(ReadData.java:20)
at ReadDataApp.main(ReadDataApp.java:18)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
I'm trying to create an insertion sort within this method. If i comment the while loop out, it no longer errors, so the error will be somewhere in there.
public void sort(){
  for(int i=1; i < array.length; i++){
  int temp = array;
int j = array[i];
while(j > 0 && (array[j-1]) > temp){
array[j] = array[j-1];
j--;
}//end of while
temp = j;
}//end of for
}//end of sortThere are 20 items in the array.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Answer 1

The error message tells you exactly what's going on: At line 20 of ReadData.java, you're trying to access the 32nd element (index 31) of an array that has 31 or fewer elements (indices 0..30 or less).
Put in some print statements so you can see where your code is not doing what you think it is.