Graph class to build a graph

Graph.java

import java.util.Collection;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Graph {

  private Collection<Edge> edges = new HashSet<Edge>();
	private Set<Vertex> vertices = new HashSet<Vertex>();

	/**
	 * A class representing a graph, can be built from an edge list
	 * 
	 * The first int is the number of edges, following this are triples of
	 * integers for each edge representing vertex u, vertex v, and the weight
	 * 
	 * @param input
	 */
	
	public Graph(String input) {
		Scanner scan = new Scanner(input);
		int count = scan.nextInt();
		for (int i = 0; i < count; i++) {
			Vertex u = new Vertex(scan.nextInt());
			Vertex v = new Vertex(scan.nextInt());
			int weight = scan.nextInt();
			vertices.add(u);
			vertices.add(v);
			edges.add(new Edge(u, v, weight));
		}
		scan.close();
	}

	public Collection<Edge> getEdgeList() {
		return edges;
	}

	public Set<Vertex> getVertices() {
		return vertices;
	}
	
}