干货 | 编程小白模拟简易比特币系统，手把手带你写一波（附代码）

public class Message implements Serializable {
/**
     * 消息内容，就是我们的区块链、交易池等所需要的信息，使用JSON.toString转化到的json字符串
     */
private String data;
/**
     * 消息类型
     */
private int type;
}

/**
 * 查询最新的区块
 */
private final static int QUERY_LATEST_BLOCK = 0;
/**
 * 查询整个区块链
 */
private final static int QUERY_BLOCK_CHAIN = 1;
/**
 * 查询交易集合
 */
private final static int QUERY_TRANSACTION = 2;
/**
 * 查询已打包的交易集合
 */
private final static int QUERY_PACKED_TRANSACTION = 3;
/**
 * 查询钱包集合
 */
private final static int QUERY_WALLET = 4;
/**
 * 返回区块集合
 */
private final static int RESPONSE_BLOCK_CHAIN = 5;
/**
 * 返回交易集合
 */
private final static int RESPONSE_TRANSACTION = 6;
/**
 * 返回已打包交易集合
 */
private final static int RESPONSE_PACKED_TRANSACTION = 7;
/**
 * 返回钱包集合
 */
private final static int RESPONSE_WALLET = 8;

P2PClient p2PClient = new P2PClient();
String url = "ws://localhost:"+args[0]+"/test";       
p2PClient.connectToPeer(url);

public void connectToPeer(String url) throws IOException, DeploymentException {
    WebSocketContainer container = ContainerProvider.getWebSocketContainer();
    URI uri = URI.create(url);
this.session = container.connectToServer(P2PClient.class, uri);
}

@OnOpen
public void onOpen(Session session) {
this.session = session;
    p2PService.sendMsg(session, p2PService.queryWalletMsg());
}

public String queryWalletMsg() {
return JSON.toJSONString(new Message(QUERY_WALLET));
}

@Override
public void sendMsg(Session session, String msg) {
session.getAsyncRemote().sendText(msg);
}

/**
 * 收到客户端发来消息
 * @param msg  消息对象
 */
@OnMessage
public void onMessage(Session session, String msg) {
    p2PService.handleMessage(session, msg);
}

@Override
public void handleMessage(Session session, String msg) {
    Message message = JSON.parseObject(msg, Message.class);
switch (message.getType()){
case QUERY_WALLET:
            sendMsg(session, responseWallets());
break;
case RESPONSE_WALLET:
            handleWalletResponse(message.getData());
break;
            ......
    }

private String responseWallets() {
String wallets = blockService.findAllWallets();
return JSON.toJSONString(new Message(RESPONSE_WALLET, wallets));
}

@Override
public String findAllWallets() {
    List wallets = new ArrayList<>();
    myWalletMap.forEach((address, wallet) ->{
        wallets.add(Wallet.builder().publicKey(wallet.getPublicKey()).build());
    });
    otherWalletMap.forEach((address, wallet) ->{
        wallets.add(wallet);
    });
return JSON.toJSONString(wallets);
}

case QUERY_WALLET:
        sendMsg(session, responseWallets());
        break;

@OnMessage
public void onMessage(String msg) {
    p2PService.handleMessage(this.session, msg);
}

case RESPONSE_WALLET:
        handleWalletResponse(message.getData());
        break;

private void handleWalletResponse(String msg) {
    List wallets = "\"[]\"".equals(msg)?new ArrayList<>():JSON.parseArray(msg, Wallet.class);
    wallets.forEach(wallet -> {
        blockService.addOtherWallet(walletService.getWalletAddress(wallet.getPublicKey()),wallet );
    });
}

public class SpringUtil implements ApplicationContextAware {
public static ApplicationContext applicationContext;
    @Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
if (SpringUtil.applicationContext != null) {
            SpringUtil.applicationContext = applicationContext;
        }
    }
/**
     * 获取applicationContext
     */
public static ApplicationContext getApplicationContext() {
return applicationContext;
    }
/** * 通过name获取 Bean. */ public static Object getBean(String name) { return getApplicationContext().getBean(name); } /** * 通过class获取Bean. */ public static T getBean(Class clazz) { return getApplicationContext().getBean(clazz); }
/** * 通过name,以及Clazz返回指定的Bean */ public static T getBean(String name, Class clazz) { return getApplicationContext().getBean(name, clazz); } } 

public static void main(String[] args) {
    System.out.println("Hello world");
    SpringUtil.applicationContext  = SpringApplication.run(Hello.class, args);
if (args.length>0){
        P2PClient p2PClient = new P2PClient();
        String url = "ws://localhost:"+args[0]+"/test";
try {
            p2PClient.connectToPeer(url);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

//之前是这样//@Autowired//private P2PService p2PService;//改正后，去掉Autowired，每次使用都手动获取beanprivate P2PService p2PService;@OnOpenpublic void onOpen(Session session) {//如果不使用那些，在这里会报空指针异常，p2PService 为 null    p2PService = SpringUtil.getBean(P2PService.class);//新增这句话从IVO容器中获取bean    p2PService.sendMsg(session, p2PService.queryWalletMsg());}