We will now look at how to implement an A* algorithm. Let's start with the code. We will use the same code that we used in the Dijkstra's search algorithm. The Vertex.java file is as follows:

public class Vertex {
    final private String id;
    final private String name;


    public Vertex(String id, String name) {
        this.id = id;
        this.name = name;
    }
// public String getId() {
// return id;
// }
//
// public String getName() {
// return name;
// }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((id == null) ? 0 : id.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Vertex other = (Vertex) obj;
        if (id == null) {
            if (other...