Read a text file which consists of the edges of the Graph and perform BFS, DFS, and Shortest Path Algorithm (Dijkstra) in Java

Question

I've been stuck in the addEdge method of my Graph class where instead of having only one "A" Vertex in my Arraylist, it creates a new one for another edge.

For example here is my text file:

A,F,2
A,C,6
B,G,4
B,H,5
C,D,8
C,F,5
D,A,1

So instead of storing it as A->[F, C], it's A->F and A->C

Here is my Graph class

import Queue.Queue;
import Stack.Stack;
import java.util.ArrayList;

public class Graph<T>{
 public ArrayList<Vertex<T>> vertexList= new ArrayList<Vertex<T>>();
  public ArrayList<Edge<T>> edgeList= new ArrayList<Edge<T>>();

 public void addEdge( T source, T destination, T weight){
  Vertex<T>VertexA=new Vertex<T>(source);
  Vertex<T> VertexB= new Vertex<T>(destination);

  if (vertexList.contains(source)){
   VertexA= vertexList.get(vertexList.indexOf(VertexA));
  }else{
   vertexList.add(VertexA);
  }
  if (vertexList.contains(VertexB)){
   VertexB= vertexList.get(vertexList.indexOf(VertexB));
  }else {
   vertexList.add(VertexB);
  }

  VertexA.addNeighbor(VertexB);
  VertexB.addNeighbor(VertexA);

  edgeList.add(new Edge<T>(VertexA,VertexB,weight));
 }

 public void BFS(Vertex<T> startingVertex) {
  startingVertex=vertexList.get(vertexList.indexOf(startingVertex));
  Vertex<T> current;
  Queue<Vertex<T>> myQueue= new Queue<Vertex<T>>();
  ArrayList<Vertex<T>> visitedList = new ArrayList<>();
  Vertex<T> startingV= vertexList.get(vertexList.indexOf(startingVertex)); // get starting vertex from vertices list\
  myQueue.enqueue(startingV); // adds the starting vertex into the queue
  while (!( myQueue.isEmpty())){
   current =  myQueue.dequeue();//removes the first element of the queue
   if (!(current.isVisited())) // sets the current vertex as visited if it is not visited
    current.setVisited(true);
    visitedList.add(current);
   // gets all the neighbors of the current vertex and adds it into the queue
   for (int i=0; i<current.getNeighbors().size(); i++){
    Vertex<T> neighbor = current.getNeighbors().get(i);
    neighbor.getVertex();
    myQueue.enqueue(neighbor);
   }

  }
  for (int i=0; i<visitedList.size(); i++){
   System.out.println(visitedList.get(i));
  }
 }
 public void DFS(T startingVertex){
  Vertex<T> startingV= vertexList.get(vertexList.indexOf(startingVertex));
  Stack<Vertex<T>> myStack= new Stack<Vertex<T>>();
  myStack.push(startingV);
  while(! myStack.isEmpty()){
   Vertex<T> current = myStack.pop();
   if (!current.isVisited()){
    current.setVisited(true);
    System.out.println(current);
   }
   for(int i=0; i<current.getNeighbors().size(); i++){
    myStack.push(current.getNeighbors().get(i));
   }
  }
 }

 public String toString(){
  System.out.println("The Graph Contains: ");
  System.out.println();
  final StringBuilder builder= new StringBuilder();
  for (int i=0; i<edgeList.size(); i++) {
   Vertex<T> source = edgeList.get(i).getSource();
   Vertex<T> destination= edgeList.get(i).getDestination();
   T weight= edgeList.get(i).getWeight();
   builder.append(source).append("--").append(weight).append("--").append(destination).append("\n");
  }
  return builder.toString();
 }
 public Vertex<T>getVertex(T data){
  Vertex<T> vertex = new Vertex<T>(data);
  return vertexList.get(vertexList.indexOf(vertex));
 }

}

In the addEdge method I also tried using for loops instead of if statements, but the output is still the same.

  for (int i=0; i<vertexList.size(); i++) {
   if (vertexList.get(i).equals(source)) {
    VertexA= vertexList.get(i);
   } else {
     VertexA=new Vertex<T>(source);
    vertexList.add(VertexA);
   }
  }
   for (int i=0; i<vertexList.size(); i++){
    if (vertexList.get(i).equals(destination)) {
     VertexB = vertexList.get(i);
    } else {
     VertexB=new Vertex<T>(destination);
     vertexList.add(VertexB);
    }
   }

// I also tried using this however it results to IndexOutOfBounds 
verexList.get(vertexList.indexOf(VertexA)).addNeighbor(VertexB);
verexList.get(vertexList.indexOf(VertexB)).addNeighbor(VertexB);

Here is how I read my text file in my main class using a readFile method

public static Graph<String> readFile(){
    Scanner sc= new Scanner(System.in);
    boolean validFile=false;
    String fileName;
    String fileContent="";
    while (!validFile) {
        try {
            System.out.print("Enter the file path of the file: ");
            fileName = sc.nextLine();

           BufferedReader reader = new BufferedReader(new FileReader(fileName));
            validFile = true;
            System.out.println(fileName + " exists! ");
            System.out.println();

            while((fileContent=reader.readLine())!=null){
                String[] row= fileContent.split(",");
                graph.addEdge(row[0], row[1], row[2]);
            }
        } catch (FileNotFoundException exception) {
            System.out.println("File does not exist");
            System.out.println("Please try again.  ");
        } catch (IOException exception) {
            exception.printStackTrace();
        }
    }
    return graph;
}