Dijkstra's Algorithm - Array Full Of Null Data

I'm trying write a Dijkstra's implementation in java. First off, here is the algorithm:

package lab3;
import java.util.HashMap;
import java.util.Stack;
 
/**
* Compute shortest paths in a graph.
*
* Your constructor should compute the actual shortest paths and maintain all the information needed to reconstruct them. The returnPath() function should use this information to return the appropriate path of edge ID's from the start to the given end.
*
* Note that the start and end ID's should be mapped to vertices using the graph's get() function.
*/
class ShortestPaths {
Multigraph graph;
final int INF = Integer.MAX_VALUE;
PriorityQueue<Integer> Q;

[Code] ....

I followed someone else psuedocode very closely but for whatever reason, my edge[] array is just full of null data, which means I can't actually return the shortest path. Why that's happening/how to fix it? Maybe I'm not understanding dijstra's correctly.