Thread: Unchecked or Unsafe Operations

I am compiling my code and I keep getting an unsafe or unchecked operations warning. I know it is just a warning, but I still need it to disappear without suppressing it. I've researched and it looks like it comes from ArrayList generalizations, but I don't know how to fix it. I've included the relevant portions of code.

//Variables at the top of class
	Vector[] adjacency;
 
//Constructor
 		adjacency = new Vector[N*N];
 		for(int i=0;i<adjacency.length;i++)
 			adjacency[i] = new Vector<Integer>();
//In a called method - node & neighbor are both ints
 		if(node<neighbor) 
			 adjacency[node].add(neighbor); 
 		else 
 			adjacency[neighbor].add(node);
 
//In another called method  - node & neighbor are both ints
				if(node<neighbor)
					if(!adjacency[node].contains(neighbor)) {
						//Add to graph and increase count
						adjacency[node].add(neighbor);
						count++;
					}
				if(neighbor<node)
					if(adjacency[neighbor].contains(node)) {
						//Add to graph and increase count
						adjacency[neighbor].add(node);
						count++;
					}

Here is the warning I get from the compiler when I ask for details (-Xlint:unchecked)

travis-mac:Project3 Travis$ javac TMMp3.java -Xlint:unchecked
TMMp3.java:76: warning: [unchecked] unchecked call to add(E) as a member of the raw type java.util.Vector
			 adjacency[node].add(neighbor); 
			                    ^
TMMp3.java:78: warning: [unchecked] unchecked call to add(E) as a member of the raw type java.util.Vector
 			adjacency[neighbor].add(node);
 			                       ^
TMMp3.java:147: warning: [unchecked] unchecked call to add(E) as a member of the raw type java.util.Vector
						adjacency[node].add(neighbor);
						                   ^
TMMp3.java:153: warning: [unchecked] unchecked call to add(E) as a member of the raw type java.util.Vector
						adjacency[neighbor].add(node);
						                       ^
4 warnings

If you can help me get this warning to go away that would be great!

Thanks,
Travis

Vector[] adjacency;

Your problem is when you create the array but I'm not sure you can use Generics with arrays. Why not make a Vector of Victors err Vectors? Roger!

Vector<Vector<Integer>> adjacency = new Vector<Vector<Integer>> ();

And why not use List and ArrayList as Vector is old and slow and if you need thread safety you can use Collections.synchronizedList.

// Json