Search code examples
javaarrayspointerspolygonintersect

Array of Polygons

I want to define Poly gon Array , so :

private static ArrayList<PolyDefault> basePolyList = new ArrayList<PolyDefault>();
//read the file and store to basePolyList
parser.readBaseFile(filename_1, basePolyList);
//get size of basePolyList
int SizeOfBase = basePolyList.size();
//def Array of polygon      
Poly[] p4=new PolyDefault[SizeOfBase];
for(int i=0;i<SizeOfBase;i++)
{
  p4[0].add(basePolyList.get(i));
  System.out.println("Poly of Base["+i+"]"+" has " +p4[i].getNumPoints()+"\n");
}

but I have this Error : Exception in thread "main" java.lang.NullPointerException ... Thanks to any Help ...

Solution

  • you have to init the objects of the Array:

    for(int i=0;i<SizeOfBase;i++)
{
    p4[i] = new Poly();
    p4[i].add(basePolyList.get(i));
    System.out.println("Poly of Base["+i+"]"+" has " +p4[i].getNumPoints()+"\n");
}