Java比特币开发教程：在开放式交易所限价买卖比特币-白红宇

上一章介绍了，你可以1秒完成资产的市价买卖。如果你想限定价格买卖，或者买卖一些exincore不支持的资产，你需要OceanOne。

方案二: 挂单Ocean.One交易所

是基于Mixin Network的去中心化交易所，它中心化交易所一样友好。你可以在OceanOne上交易任何资产，只需要将你的币转给OceanOne, 将交易信息写在交易的memo里，OceanOne会在市场里列出你的交易需求，交易成功后，会将目标币转入到你的MixinNetwork帐上，它有三大特点与优势：

不需要在OceanOne注册

不需要存币到交易所

支持所有Mixin Network上能够转账的资产，所有的ERC20 EOS代币。

预备知识:

你先需要创建一个机器人, 方法在 .

安装依赖包

正如教程一里我们介绍过的，我们需要依赖 , 你应该先安装过它了，zhang/mixin_labs-java-bot/blob/master/README.md).

Install required packages

, 在上一课中已经安装好了.

充币到 Mixin Network, 并读出它的余额.

此处演示用 USDT购买BTC 或者用BTC购买USDT。交易前，先检查一下钱包地址。完整的步骤如下:

检查比特币或USDT的余额，钱包地址。并记下钱包地址。

从第三方交易所或者你的冷钱包中，将币充到上述钱包地址。

再检查一下币的余额，看到帐与否。(比特币的到帐时间是5个区块的高度，约100分钟)。

比特币与USDT的充值地址是一样的。

private static final String BTC_ASSET_ID     = "c6d0c728-2624-429b-8e0d-d9d19b6592fa";  private static final String EOS_ASSET_ID     = "6cfe566e-4aad-470b-8c9a-2fd35b49c68d";  private static final String USDT_ASSET_ID    = "815b0b1a-2764-3736-8faa-42d694fa620a";  MixinAPI mixinApiUser = generateAPI_FromCSV();  JsonObject asset = mixinApiUser.getAsset(BTC_ASSET_ID);  System.out.println(asset);  System.out.println("------------------------BTC------Information---------------------------");  System.out.println("The BTC wallet address is " + asset.get("public_key").getAsString());  System.out.println("The BTC wallet balance is " + asset.get("balance").getAsString());  System.out.println("-----------------------------------------------------------------------");复制代码

取得Ocean.one的市场价格信息

如何来查询Ocean.one市场的价格信息呢？你要先了解你交易的基础币是什么，如果你想买比特币，卖出USDT,那么基础货币就是USDT;如果你想买USDT,卖出比特币，那么基础货币就是比特币.

if ( subinput.equals("1") ) {  FetchOceanMarketInfos(BTC_ASSET_ID,USDT_ASSET_ID);}private static void FetchOceanMarketInfos(String targetAssetID, String baseAssetID) {  OkHttpClient client = new OkHttpClient();  String baseUrl = "https://events.ocean.one/markets/%s-%s/book ";  String fullUrl = String.format(baseUrl,targetAssetID,baseAssetID);  // String fullUrl = baseUrl + url;  System.out.println(fullUrl);  Request request = new Request.Builder()                             .url(fullUrl)                             .build();  try {     Response response = client.newCall(request).execute();     if (!response.isSuccessful()) {       throw new IOException("Unexpected code " + response);     }     String res = response.body().string();     // System.out.println(res);     JsonParser parser = new JsonParser();     JsonElement jsonTree = parser.parse(res);     JsonObject orders;     orders =  jsonTree.getAsJsonObject();     JsonArray asksOrders = orders.get("data").getAsJsonObject().                                   get("data").getAsJsonObject().                                   get("asks").getAsJsonArray();     JsonArray bidsOrders = orders.get("data").getAsJsonObject().                                   get("data").getAsJsonObject().                                   get("bids").getAsJsonArray();     // System.out.println(orders.get("data").getAsJsonObject().get("data").getAsJsonObject().get("bids").getAsJsonArray());     System.out.println("--Side--Price--Amount--Funds---");     asksOrders.forEach((element) ->  {        JsonObject jsonObj = element.getAsJsonObject();        System.out.println(jsonObj.get("side").getAsString() + " " +                           jsonObj.get("price").getAsString() + " " +                           jsonObj.get("amount").getAsString() + " " +                           jsonObj.get("funds").getAsString() );     });     bidsOrders.forEach((element) ->  {        JsonObject jsonObj = element.getAsJsonObject();        System.out.println(jsonObj.get("side").getAsString() + " " +                           jsonObj.get("price").getAsString() + " " +                           jsonObj.get("amount").getAsString() + " " +                           jsonObj.get("funds").getAsString() );     });     System.out.println("----endo--of--btc/usdt----");     return;   } catch(Exception e) { e.printStackTrace(); }   return;}复制代码

交易前，创建一个Memo!

在第二章里,, 我们学习过转帐，这儿我们介绍如何告诉Ocean.one，我们给它转帐的目的是什么，信息全部放在memo里.

Side 方向,"B" 或者 "A", "B"是购买, "A"是出售.

AssetUUID 目标虚拟资产的UUID.

Price 价格，如果操作方向是"B", 价格就是AssetUUID的价格; 如果操作方向是"B", 价格就是转给Ocean.one币的价格.

public static String GenerateOrderMemo(String Side, String AssetUUID, String Price) {  try {    MessageBufferPacker m = MessagePack.newDefaultBufferPacker();    UUID myAssetUUID  =  UUID.fromString(AssetUUID);    Value map = ValueFactory.newMap(ValueFactory.newString("S"), ValueFactory.newString(Side),                                    ValueFactory.newString("A"), ValueFactory.newBinary(asBytes(myAssetUUID)),                                    ValueFactory.newString("P"), ValueFactory.newString(Price),                                    ValueFactory.newString("T"), ValueFactory.newString("L") );    m.packValue(map);    return Base64.getEncoder().encodeToString(m.toByteArray());  } catch (Exception e) { e.printStackTrace(); }    return "";}复制代码

出售BTC的例子

转打算出售的BTC给Ocean.one(OCEANONE_BOT),将你打算换回来的目标虚拟资产的UUID放入memo.

private static final String OCEANONE_BOT     = "aaff5bef-42fb-4c9f-90e0-29f69176b7d4";private static final String BTC_ASSET_ID     = "c6d0c728-2624-429b-8e0d-d9d19b6592fa";private static final String EOS_ASSET_ID     = "6cfe566e-4aad-470b-8c9a-2fd35b49c68d";private static final String USDT_ASSET_ID    = "815b0b1a-2764-3736-8faa-42d694fa620a";private static final String BTC_WALLET_ADDR  = "14T129GTbXXPGXXvZzVaNLRFPeHXD1C25C";private static final String MASTER_UUID      = "0b4f49dc-8fb4-4539-9a89-fb3afc613747";if ( subinput.equals("s1") ) {  System.out.print("Please input the BTC price base USDT: ");  String pinput = System.console().readLine();  System.out.println(pinput);  System.out.print("Please input the BTC amount: ");  String aminput = System.console().readLine();  System.out.println(aminput);  float amountf = Float.valueOf(aminput.trim()).floatValue();  String buyMemo = GenerateOrderMemo("A",USDT_ASSET_ID,pinput);  MixinAPI mixinApiUser = generateAPI_FromCSV();  // UUID usdtUUID         =  UUID.fromString(USDT_ASSET_ID);  // String memoTarget     = encodeUUID(usdtUUID);  System.out.println("------------------Ocean.one-USDT-BTC-EXCHANGE----------------------------");  System.out.println(buyMemo);  JsonObject asset = mixinApiUser.getAsset(BTC_ASSET_ID);  System.out.println(asset);  System.out.println(asset.get("balance").getAsFloat());  if ( asset.get("balance").getAsFloat()  > 0 && asset.get("balance").getAsFloat() >= amountf ) {      JsonObject transInfo = mixinApiUser.transfer(BTC_ASSET_ID, OCEANONE_BOT,                                                 aminput,                                                 buyMemo);      System.out.println("------------------------BTC Transfer To EXCHANGE Information----------------------");      System.out.println(transInfo);      System.out.println("-----------------------------------------------------------------------");   } else System.out.println("----------------Not enough BTC--------------------------------------------");}复制代码

如果你是打算买BTC,操作如下:

if ( subinput.equals("b1") ) {  System.out.print("Please input the BTC price base USDT: ");  String pinput = System.console().readLine();  System.out.println(pinput);  System.out.print("Please input the USDT amount: ");  String aminput = System.console().readLine();  System.out.println(aminput);  float amountf = Float.valueOf(aminput.trim()).floatValue();  String buyMemo = GenerateOrderMemo("B",BTC_ASSET_ID,pinput);  MixinAPI mixinApiUser = generateAPI_FromCSV();  // UUID usdtUUID         =  UUID.fromString(USDT_ASSET_ID);  // String memoTarget     = encodeUUID(usdtUUID);  System.out.println("------------------Ocean.one-USDT-BTC-EXCHANGE----------------------------");  System.out.println(buyMemo);  JsonObject asset = mixinApiUser.getAsset(USDT_ASSET_ID);  System.out.println(asset);  System.out.println(asset.get("balance").getAsFloat());  if ( asset.get("balance").getAsFloat()  >= 1 && asset.get("balance").getAsFloat() >= amountf ) {      JsonObject transInfo = mixinApiUser.transfer(USDT_ASSET_ID, OCEANONE_BOT,                                                 aminput,                                                 buyMemo);      System.out.println("------------------------BTC Transfer To EXCHANGE Information----------------------");      System.out.println(transInfo);      System.out.println("-----------------------------------------------------------------------");   } else System.out.println("----------------Not enough USDT--------------------------------------------");}复制代码

一个成功的挂单如下：

------------------Ocean.one--EXCHANGE----------------------------hKFToUKhQcQQyUrIj0ZxOXa2CgkGTxgR6KFQojExoVShTA=={
   "type":"asset","asset_id":"815b0b1a-2764-3736-8faa-42d694fa620a","chain_id":"c6d0c728-2624-429b-8e0d-d9d19b6592fa","symbol":"USDT","name":"Tether USD","icon_url":"https://images.mixin.one/ndNBEpObYs7450U08oAOMnSEPzN66SL8Mh-f2pPWBDeWaKbXTPUIdrZph7yj8Z93Rl8uZ16m7Qjz-E-9JFKSsJ-F=s128","balance":"2","public_key":"15RNBb5GzoXWRoEMT5MJL3pqzSjdPoXf6J","account_name":"","account_tag":"","price_btc":"0.00018747","price_usd":"0.98731224","change_btc":"0.021985715750932774","change_usd":"-0.01843154053058167","asset_key":"815b0b1a-2764-3736-8faa-42d694fa620a","confirmations":6,"capitalization":0}2.0--------------815b0b1a-2764-3736-8faa-42d694fa620a Transfer To EXCHANGE Information---------{
   "type":"transfer","snapshot_id":"f526fd18-c3d2-4a6d-a0f0-3a720e93c48e","opponent_id":"aaff5bef-42fb-4c9f-90e0-29f69176b7d4","asset_id":"815b0b1a-2764-3736-8faa-42d694fa620a","amount":"-2","trace_id":"6cf37ca6-4efa-4e78-bea1-53c5c5d54d2b","memo":"hKFToUKhQcQQyUrIj0ZxOXa2CgkGTxgR6KFQojExoVShTA==","created_at":"2019-04-26T01:56:00.803572612Z","counter_user_id":"0b4f49dc-8fb4-4539-9a89-fb3afc613747"}---Order is 6cf37ca6-4efa-4e78-bea1-53c5c5d54d2b: ------复制代码

取消挂单

Ocean.one将trace_id当做订单，比如上面的例子， 6cf37ca6-4efa-4e78-bea1-53c5c5d54d2b 就是订单号，我们用他来取消订单。

public static String GenerateOrderCancelMemo(String myUuid) {  try {    MessageBufferPacker m = MessagePack.newDefaultBufferPacker();    UUID AssetUUID  =  UUID.fromString(myUuid);    Value map = ValueFactory.newMap(                                    ValueFactory.newString("O"), ValueFactory.newBinary(asBytes(AssetUUID)) );    m.packValue(map);    return Base64.getEncoder().encodeToString(m.toByteArray());  } catch (Exception e) { e.printStackTrace(); }    return "";}复制代码

通过读取资产余额，来确认到帐情况

Check the wallet's balance.

MixinAPI mixinApiUser = generateAPI_FromCSV();JsonObject asset = mixinApiUser.getAsset(BTC_ASSET_ID);复制代码

源代码执行

编译执行，即可开始交易了.

gradle build 编译项目.

java -cp 运行项目.

java -cp .:build/libs/bitcoin_wallet-java.jar:libs/* bitcoin_wallet.java.App复制代码

注意：不能使用gradle run来运行，因为我们使用的System.console().readLine()不被Gradle支持，只能使用java -cp 来运行！

本代码执行时的命令列表:

1: Create Bitcoin Wallet and update PIN

2: Read Bitcoin balance & address

3: Read USDT balance & address

4: Read EOS balance & address

tbb:Transfer BTC from Bot to Wallet

tbm:Transfer BTC from Wallet to Master

teb:Transfer EOS from Bot to Wallet

tem:Transfer EOS from Wallet to Master

tub:Transfer USDT from Bot to Wallet

tum:Transfer USDT from Wallet to Master

5: pay 0.0001 BTC buy USDT

6: pay $1 USDT buy BTC

7: Read Snapshots

8: Fetch market price(USDT)

9: Fetch market price(BTC)

v: Verify Wallet Pin

wb: Withdraw BTC

we: WitchDraw EOS

a: Read All Assets Infos

o: Ocean.One Exchange

q: Exit

Make your choose(eg: q for Exit!):

1: Orders-Book of BTC/USDT

b1: Buy BTC pay USDT

s1: Sell BTC get USDT

2: Orders-Book of EOS/USDT

b2: Buy EOS pay USDT

s2: Sell EOS get USDT

3: Orders-Book of XIN/USDT

b3: Buy XIN pay USDT

s3: Sell XIN get USDT

4: Orders-Book of XIN/BTC

b4: Buy XIN pay BTC

s4: Sell XIN get BTC

5: Orders-Book of EOS/BTC

b4: Buy EOS pay BTC

s4: Sell EOS get BTC

6: Orders-Book of SC/BTC

b6: Buy SC pay BTC

s6: Sell SC get BTC

7: Orders-Book of EOS/XIN

b7: Buy EOS pay XIN

s7: Sell EOS get XIN

8: Orders-Book of ETH/XIN

b8: Buy ETH pay XIN

s8: Sell EOS get XIN

9: Orders-Book of SC/XIN

b9: Buy SC pay XIN

s9: Sell SC get XIN

c: Cancel the order

q: Exit