区块链（7）：p2p去中心化之初始化websoket服务端

1 整个流程梳理

• 服务开启onStart()
• 连接打开onOpen()
• 处理接收到的消息onMesage()
• 连接关闭onClose()
• 异常处理onError()

2 创建p2p实现类

package com.example.demo.service;

import com.example.demo.entity.BlockChain;
import org.java_websocket.WebSocket;
import org.java_websocket.handshake.ClientHandshake;
import org.java_websocket.server.WebSocketServer;

import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

public class P2PService {
    private List sockets;
    private BlockChain blockService;

    /**
     * p2p服务初始化
     * @param blockService
     */
    public P2PService(BlockChain blockService) {
        this.blockService = blockService;
        this.sockets = new ArrayList<