如何在Java中将字符串‘转换’为顶点来创建图形？

import java.util.*;

// 图的类
class Graph {
    private Map<String, Vertex> vertices;  // 顶点集合
    
    public Graph() {
        vertices = new HashMap<>();
    }
    
    // 添加顶点
    public void addVertex(Vertex vertex) {
        vertices.put(vertex.getName(), vertex);
    }
    
    // 添加边
    public void addEdge(Vertex from, Vertex to) {
        from.addNeighbour(to);
        to.addNeighbour(from);
    }
}

// 顶点类
class Vertex {
    private String name;  // 顶点名称
    private List<Vertex> neighbours;  // 相邻顶点集合
    
    public Vertex(String name) {
        this.name = name;
        neighbours = new ArrayList<>();
    }
    
    public String getName() {
        return name;
    }
    
    public void addNeighbour(Vertex neighbour) {
        neighbours.add(neighbour);
    }
}

public class Main {
    public static void main(String[] args) {
        Graph graph = new Graph();
        
        // 创建顶点
        Vertex vertex1 = new Vertex("A");
        Vertex vertex2 = new Vertex("B");
        Vertex vertex3 = new Vertex("C");
        
        // 添加顶点到图中
        graph.addVertex(vertex1);
        graph.addVertex(vertex2);
        graph.addVertex(vertex3);
        
        // 添加边
        graph.addEdge(vertex1, vertex2);
        graph.addEdge(vertex2, vertex3);
        
        // 其他操作...
    }
}