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简单的应用开发：使用bitcoinj客户端监听转账，和发起转账

本章介绍如何使用bitcoinj客户端监听转账，和发起转账。demo工程：https://github.com/berryjam/bitcoinj 是基于bitcoinj的基础上，作了以下小改动：

  • 修改了build.gradle，添加了google()仓库，避免编译过程中出现找不到guava包的问题，改动如图3-2所示。

图 3-2. 右边绿色区域为改动内容

  • 修改了examples/build.gradle，添加了application插件，使得gradle可以运行指定例子，如通过mainClass指定要运行类，gradle -PmainClass=org.bitcoinj.examples.FetchBlock run --args=000000000000001535467706e8545b339e7e0adca408c5432781f4da0e94d734，改动如图3-3所示。

图 3-3. 右边区域为改动内容

  • 修改了examples/src/main/java/org.bitcoinj.examples/Kit.java，让Kit后台运行并监听转账后再给个人UniSat钱包地址转账。
  • 修改了examples/src/main/java/org.bitcoinj.examples/FetchBlock.java，检索指定块里给个人地址转账交易信息。

准备工作

以下两个例子都是在测试网(testnet)进行，请先安装BTC钱包（如UniSat的chrome插件）和领取测试币，https://altquick.com/swap/ 也可以换取测试币。

{% hint style="info" %} 关于testnet、signet、regtest区别请参考《第十一章：比特币的测试区块链》一节。 {% endhint %}

图 3-4. UniSat钱包，领取测试币

拉取代码：

$git clone [email protected]:berryjam/bitcoinj.git
$cd bitcoinj/examples

本地生成钱包和监听转账：

$gradle -PmainClass=org.bitcoinj.examples.Kit run

此刻如果正常运行，可以看到一些输出信息，并且examples目录下会生成两个文件，分别是：测试链交易信息walletappkit-example.spvchain，及个人钱包walletappkit-example.wallet。

查看本地账户地址：

由于Kit在后台运行，会锁住钱包文件，需要先关掉。使用WalletTool的dump命令可以查看钱包地址，其中参数--chain和--wallet指定上面两个文件路径，--net选择testnet。

$cd wallettool
$gradle -PmainClass=org.bitcoinj.wallettool.WalletTool run --args='dump --chain ${本地目录}/bitcoinj/examples/walletappkit-example.spvchain --wallet ${本地目录}/bitcoinj/examples/walletappkit-example.wallet --net testnet'

正常运行，会看到以下信息，包含钱包地址：

Wallet
Balances:
  0.00 BTC ESTIMATED
  0.00 BTC AVAILABLE
  0.00 BTC ESTIMATED_SPENDABLE
  0.00 BTC AVAILABLE_SPENDABLE
Transactions:
  0 pending
  0 unspent
  0 spent
  0 dead
Last seen best block: 2582064 (2024-03-15T12:42:50Z): 0000000000000007836260bd967b437a6a4d993fecafb22f2ab53a5da71d0aeb

Keys:
Earliest creation time: 2024-03-15T12:25:55Z
Seed birthday:     1710505555  [2024-03-15T12:25:55Z]
Ouput script type: P2PKH
Key to watch:      tpubD9XNB5hPxkwtc26UYmLDPLYGZZR1GLQ9KGYPeiWZZbqpWMcQbhc7gogbeSPvsQ6yybiYm9HraXLzYWWKnvASbgVB7FEZtBWnrMEtabrkYSx
Lookahead siz/thr: 100/33
  addr:mwBKsLnLBN2SLsca6gUEyBUa62aE1mDzqV  hash160:abcbb3cacded05d9e55b9b2b63781bb1cf799061  (m, root)
  addr:mnMRvhAaK51FrCFSSnXvmmvwB7qNRFZkDd  hash160:4afbc9628f5cb039d7de8468e99cd90fb02dd6e2  (m/0H, account)
  addr:mzCSon2Bcp2k7fDxEK1eSqTT2SgVMZCdwP  hash160:ccea49a1d36d9c974e674b3e5b1231dae850d116  (m/0H/0, external)
  addr:n4CZ2wLTirF1TLRgdJcL1VEBPcFetaxQ6a  hash160:f8cffd1ccec1f6119122d0ec0b4b9a69f9cc11bd  (m/0H/1, internal)

Seed birthday:     1710505555  [2024-03-15T12:25:55Z]
Ouput script type: P2WPKH
Key to watch:      vpub5VVD3WXsx7uUffZQvJfyq2hQaTvK4iVedZGsBvtXDa9zkZjMwJAKMyVH6xKMApnLchJGMpuMvEcJSmTjYLeqtZ7EkrDFtsUL2pEjzyTxaeJ
Lookahead siz/thr: 100/33
  addr:tb1q409m8jkda5zane2mnv4kx7qmk88hnyrpemvls6  hash160:abcbb3cacded05d9e55b9b2b63781bb1cf799061  (m, root)
  addr:tb1q7cp7xg0wdm9r46uwckagj8al3p9p6gcggmvyec  hash160:f603e321ee6eca3aeb8ec5ba891fbf884a1d2308  (m/1H, account)
  addr:tb1q30nky20w8gae6ednt2tkt48zakytw6kgckkhr3  hash160:8be76229ee3a3b9d65b35a9765d4e2ed88b76ac8  (m/1H/0, external)
  addr:tb1q6k35lxctlknaesw4ckxnngxl7q3f7awhn3de82  hash160:d5a34f9b0bfda7dcc1d5c58d39a0dff0229f75d7  (m/1H/1, internal)
  addr:tb1qh8h3zgr9g9zgqhed7e9ldp943xqz5vgn62pxnj  hash160:b9ef1120654144805f2df64bf684b589802a3113  (M/1H/0/0)

其中一个P2WPKH类型账户：tb1q7cp7xg0wdm9r46uwckagj8al3p9p6gcggmvyec。

{% hint style="info" %} 钱包和地址类型，请参考《第五章：钱包技术栈的详细介绍》一节。 {% endhint %}

转账

重新让Kit后台运行，监听转账信息，并且余额足够的情况下给UniSat钱包转出0.00001 BTC。

使用UniSat钱包给上面bitcoinj钱包地址转账：

图 3-5. 给bitcoinj钱包转账

正常情况下，可以看到Kit后台输出以下打印信息：

-----> coins resceived: df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4
3月 15, 2024 9:03:26 下午 org.bitcoinj.wallet.WalletFiles saveNow
信息: Saving wallet; last seen block is height 2582067, date 2024-03-15T12:54:20Z, hash 000000000000000e5646ea505bb9106ca776d8f513fa7248c043e9324b2f5136
3月 15, 2024 9:03:26 下午 org.bitcoinj.wallet.WalletFiles saveNowInternal
信息: Save completed in 22 ms
3月 15, 2024 9:03:26 下午 org.bitcoinj.wallet.DeterministicKeyChain maybeLookAhead
信息: 0 keys needed for M/0H/0 = 0 issued + 100 lookahead size + 33 lookahead threshold - 133 num children
3月 15, 2024 9:03:26 下午 org.bitcoinj.wallet.DeterministicKeyChain maybeLookAhead

其中df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4为交易hash，在区块链浏览器上可以看到：https://mempool.space/zh/testnet/tx/df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4 具体内容。

在代码里，第一次接收到0.00005 BTC后，会给UniSat转账，却发现钱不够。


kit.wallet().addCoinsReceivedEventListener((wallet, tx, prevBalance, newBalance) -> {
            System.out.println("-----> coins resceived: " + tx.getTxId());
            System.out.println("received: " + tx.getValue(wallet));
            Address to = kit.wallet().parseAddress("tb1qeww9d68r9xyka203zpzmwmwc94rp8sqfgekhwn");
            Coin value = Coin.parseCoin("0.00001");
            org.bitcoinj.wallet.SendRequest req = org.bitcoinj.wallet.SendRequest.to(to, value);
            req.setFeePerVkb(Coin.valueOf(1100));
            try {
                Wallet.SendResult result = wallet.sendCoins(req);
                System.out.println("coins sent. transaction hash: " + result.transaction().getTxId());
            } catch (InsufficientMoneyException e) {
                System.out.println("Not enough coins in your wallet. Missing " + e.missing.getValue() + " satoshis are missing (including fees)");
                System.out.println("Please send enough money to: " + wallet.currentReceiveAddress().toString());
            }
        });

Not enough coins in your wallet. Missing 1000 satoshis are missing (including fees)
Please send enough money to: tb1qh8h3zgr9g9zgqhed7e9ldp943xqz5vgn62pxnj
-----> confidence changed: df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4
new block depth: 0
-----> confidence changed: df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4

深入转账代码，可以发现钱包会从账户的UTXO列表里选择最佳可用的输出（第二章的币种选择一节有过相关介绍），从里面按照最大可用金额排序，然后累加直到满足转账金额。关键是shouldSelect函数，里面会判断交易状态。因为刚接收到的交易，还没得到确认，因此无法用于转账。

Wallet.SendResult result = wallet.sendCoins(req);
...
public CoinSelection select(Coin target, List<TransactionOutput> candidates) {
        ArrayList<TransactionOutput> selected = new ArrayList<>();
        // Sort the inputs by age*value so we get the highest "coindays" spent.
        // TODO: Consider changing the wallets internal format to track just outputs and keep them ordered.
        ArrayList<TransactionOutput> sortedOutputs = new ArrayList<>(candidates);
        // When calculating the wallet balance, we may be asked to select all possible coins, if so, avoid sorting
        // them in order to improve performance.
        if (!target.equals(BitcoinNetwork.MAX_MONEY)) {
            sortedOutputs.sort(DefaultCoinSelector::compareByDepth);
        }
        // Now iterate over the sorted outputs until we have got as close to the target as possible or a little
        // bit over (excessive value will be change).
        long total = 0;
        for (TransactionOutput output : sortedOutputs) {
            if (total >= target.value) break;
            // Only pick chain-included transactions, or transactions that are ours and pending.
            if (!shouldSelect(output.getParentTransaction())) continue;
            selected.add(output);
            total = Math.addExact(total, output.getValue().value);
        }
        // Total may be lower than target here, if the given candidates were insufficient to create to requested
        // transaction.
        return new CoinSelection(selected);
    }

等待一段时间交易得到确认后，重新转账0.00001 BTC，再次触发转账交易，可以看到输出：

coins sent. transaction hash: 910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e
-----> confidence changed: 4618ab0373121312f95bab45ae408e8c5d87acd63262adb17f7af93609c9fb0c
new block depth: 0
-----> coins resceived: 910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e

可以在区块链浏览器上看到交易信息：https://mempool.space/zh/testnet/tx/910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e。

拉块

最后是一个简单的监控转账的小功能，比如我们需求是需要监听链上所有交易信息，然后对感兴趣的地址转账再做一些后处理。

图 3-6. 交易所在块信息

1.获取对应的交易信息

遍历块的所有交易信息，通过交易hash筛选出转账交易。

        for (Transaction tx : txs) {
            if ("910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e".equals(tx.getTxId().toString())) {
                System.out.println("tx: " + tx);
                ...
            }
        }

2.获取输入地址

观察交易的输入信息，可以看到witness和地址类型信息(这里为P2WPKH)，但是从witness怎么获取到发送方地址呢？

图 3-7. 交易输入信息

我们可以通过Transaction.java的函数了解到input的witness是怎么构造出来的。

public TransactionInput addSignedInput(TransactionOutPoint prevOut, Script scriptPubKey, Coin amount, ECKey sigKey,
                                           SigHash sigHash, boolean anyoneCanPay) throws ScriptException {
        ...
        if (ScriptPattern.isP2PK(scriptPubKey)) {
            ...
        } else if (ScriptPattern.isP2PKH(scriptPubKey)) {
            ...
        } else if (ScriptPattern.isP2WPKH(scriptPubKey)) { // 示例为P2WPKH
            Script scriptCode = ScriptBuilder.createP2PKHOutputScript(sigKey);
            TransactionSignature signature = calculateWitnessSignature(inputIndex, sigKey, scriptCode, input.getValue(),
                    sigHash, anyoneCanPay);
            input.setScriptSig(ScriptBuilder.createEmpty());
            input.setWitness(TransactionWitness.redeemP2WPKH(signature, sigKey));
        } else {
            throw new ScriptException(ScriptError.SCRIPT_ERR_UNKNOWN_ERROR, "Don't know how to sign for this kind of scriptPubKey: " + scriptPubKey);
        }
        return input;
    }

可以看到通过TransactionWitness.redeemP2WPKH(signature, sigKey)构造出来witness，其中包含了sigKey，继续深入redeemP2WPKH函数就可以知道这个参数就是发送方的PubKey，并且放在witness的第二个位置（下标为0）。

    public static TransactionWitness redeemP2WPKH(@Nullable TransactionSignature signature, ECKey pubKey) {
        checkArgument(pubKey.isCompressed(), () ->
                "only compressed keys allowed");
        List<byte[]> pushes = new ArrayList<>(2);
        pushes.add(signature != null ? signature.encodeToBitcoin() : new byte[0]); // signature
        pushes.add(pubKey.getPubKey()); // pubkey , witness的第2个位置
        return TransactionWitness.of(pushes);
    }

有了公钥，就可以根据账户和网络类型算出对应的地址。

byte[] publicKeyBytes = input.getWitness().getPush(1); // 第二个位置，下标为1，存放的的是pubKey
// 创建一个 ECKey 对象并导入公钥
ECKey ecKey = ECKey.fromPublicOnly(publicKeyBytes);

// 将 ECKey 对象转换为 Bitcoin 地址
Address from = ecKey.toAddress(ScriptType.P2WPKH, network); // 如果是测试网络，请改为 TestNetParams.get()

3.获取输出地址和金额

遍历所有输出，通过转出地址筛选出我们所关心的输出，类似输入，地址可以从输出脚本解析得到，输出金额直接从output获取到。

List<TransactionOutput> outputs = tx.getOutputs();
for (TransactionOutput output : outputs) {
     Script pubKey = output.getScriptPubKey();
     Address to = pubKey.getToAddress(network);
     if ("tb1qeww9d68r9xyka203zpzmwmwc94rp8sqfgekhwn".equals(to.toString())) {
          System.out.printf("from:%s to:%s receive: %s\n", from, to, output.getValue().toFriendlyString());
     }
}

4.综合运行

将上面逻辑整合起来，运行examples/src/main/java/org.bitcoinj.examples/FetchBlock.java

gradle -PmainClass=org.bitcoinj.examples.FetchBlock run --args=000000009661aeca0d6092068575fe5113455fe2d28d200d367c57829686f6e9

输出如下：

16:29:40.246 28 PeerGroup.handleNewPeer: Peer{[18.162.45.10]:18333, version=70016, subVer=/Satoshi:0.21.0/, services=NETWORK, WITNESS, NETWORK_LIMITED, time=2024-03-15T16:29:40Z, height=2582085}: New peer      (10 connected, 2 pending, 12 max)
tx: Transaction{910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e, wtxid d69b107bdc9079022593bd9964315fef07fba08d2789648d98bbdf8c0b94fe7f
weight: 561 wu, 141 virtual bytes, 222 bytes
purpose: UNKNOWN
   in   <empty>
        witness:304402201f1559071f66bf9c41de50a2c0797330a1a3877bf7ee26f039e10b7153379d12022000da463d0bd87a9b75369bc4b6713e2bceb4553d05870d86b5a846b428d7f4b701 026b7ba89cb3249b8afe1d9bac77dadd178e995f258cb809f34ec03d1bc62999cd
        unconnected  outpoint:df2b71b76cfc6ae8f2142204a2460b348d438f5f2a05f61b57b3239ee20cc5b4:0
   out  0[] PUSHDATA(20)[8252a735bc09ac9604356407b9e67528f4af6298]  0.00003845 BTC
        P2WPKH
   out  0[] PUSHDATA(20)[cb9c56e8e329896ea9f11045b76dd82d4613c009]  0.00001 BTC
        P2WPKH
}
from:tb1q7cp7xg0wdm9r46uwckagj8al3p9p6gcggmvyec to:tb1qeww9d68r9xyka203zpzmwmwc94rp8sqfgekhwn receive: 0.00001 BTC

可以看到接收来自tb1q7cp7xg0wdm9r46uwckagj8al3p9p6gcggmvyec，发送到tb1qeww9d68r9xyka203zpzmwmwc94rp8sqfgekhwn，一共0.00001 BTC的转账信息。

{% hint style="info" %} 关于交易的结构信息，请参考《第六章：交易》。 {% endhint %}

使用单独部署的测试全节点

由于上述例子使用的测试网公开的节点进行同步区块信息，这些公开节点可能会请求进行限频等，导致交易监听和转账出现问题。因此建议在本地部署一个测试网全节点，专用的节点获取交易信息和处理效率都很会非常高。

1.下载bitcoin core

根据运行操作系统选择合适的版本：https://bitcoincore.org/en/download/

$cd ~/download
$wget https://bitcoincore.org/bin/bitcoin-core-26.0/bitcoin-26.0-x86_64-linux-gnu.tar.gz

2.解压和设置

$tar -xvf bitcoin-26.0-x86_64-linux-gnu.tar.gz
$export PATH=$PATH:/root/download/bitcoin-26.0/bin

正常情况下，能够识别节点bitcoind和命令行工具bitcoin-cli

$which bitcoind
/root/download/bitcoin-26.0/bin/bitcoind
$which bitcoin-cli
/root/download/bitcoin-26.0/bin/bitcoin-cli

3.配置运行参数

接着就可以配置运行参数文件

$mkdir -p /data/bitcoin
$touch /data/bitcoin/bitcoin.conf

大致参数如下，由于用的测试网，所以只配置了[test]。其中datadir为存储区块交易的数据目录，txindex 是一个用于控制是否启用事务索引的参数。如果设置为 1，则表示启用事务索引，允许通过事务哈希来快速查找交易的详细信息，建议开启，不过会更占用磁盘空间。peerbloomfilters=1，表示允许开启布隆过滤器，bitcoinj项目这个参数必须设置为1，否则会拉取不到数据。rpcallowip=0.0.0.0/0设置为允许所有机器能够连接，rpcbind=0.0.0.0设置监听来自所有ip的连接，默认为127.0.0.1，会导致远程机器连接不上。

# Options for mainnet
[main]

# Options for testnet
[test]
datadir=/data/bitcoin/testnet/data
#prune=51200
shrinkdebuglog=1
rpcuser=berry
rpcpassword=123456
rpcallowip=0.0.0.0/0
rpcbind=0.0.0.0
txindex=1
peerbloomfilters=1

# Options for signet
[signet]

# Options for regtest
[regtest]

4.运行bitcoind和确认

指定运行配置文件、网络和后台运行

$bitcoind --conf=/data/bitcoin/bitcoin.conf -testnet -daemon

第一次启动时，节点需要同步最新的区块数据，需要等待一会。正常情况下，通过bitcoin-cli就能查询到上述的交易信息

$bitcoin-cli -testnet -rpcuser=berry -rpcpassword=123456 getrawtransaction 910e4fa1e07a192a33986dc45c6857ff33391cabe0ff87e733fda7ea0f71379e
01000000000101b4c50ce29e23b3571bf6052a5f8f438d340b46a2042214f2e86afc6cb7712bdf0000000000ffffffff02050f0000000000001600148252a735bc09ac9604356407b9e67528f4af6298e803000000000000160014cb9c56e8e329896ea9f11045b76dd82d4613c0090247304402201f1559071f66bf9c41de50a2c0797330a1a3877bf7ee26f039e10b7153379d12022000da463d0bd87a9b75369bc4b6713e2bceb4553d05870d86b5a846b428d7f4b70121026b7ba89cb3249b8afe1d9bac77dadd178e995f258cb809f34ec03d1bc62999cd00000000

5.代码设置Peer为本地节点

测试节点的P2P默认端口为18333，RPC端口为18332，正式网分别为8333、8332。

WalletAppKit kit = WalletAppKit.launch(network, new File("."), "walletappkit-example", (k) -> {
            // In case you want to connect with your local bitcoind tell the kit to connect to localhost.
            // This is done automatically in reg test mode.
            // k.connectToLocalHost();
            try {
                k.setPeerNodes(PeerAddress.simple(InetAddress.getByName("127.0.0.1"), 18333)); // 设置本地连接Peer节点
            } catch (UnknownHostException e) {
                e.printStackTrace();
            }
        });

正常情况下，使用本地全节点能避免很多问题。

bitcoinj常见问题

1.钱包加载异常

Exception in thread "main" java.lang.IllegalStateException: Expected the service WalletAppKit [FAILED] to be RUNNING, but the service has FAILED
	at com.google.common.util.concurrent.AbstractService.checkCurrentState(AbstractService.java:384)
	at com.google.common.util.concurrent.AbstractService.awaitRunning(AbstractService.java:308)
	at com.google.common.util.concurrent.AbstractIdleService.awaitRunning(AbstractIdleService.java:160)
	at org.bitcoinj.kits.WalletAppKit.launch(WalletAppKit.java:220)
	at org.bitcoinj.kits.WalletAppKit.launch(WalletAppKit.java:178)
	at org.bitcoinj.examples.Kit.main(Kit.java:57)
Caused by: org.bitcoinj.wallet.UnreadableWalletException: Could not parse input stream to protobuf
	at org.bitcoinj.wallet.WalletProtobufSerializer.readWallet(WalletProtobufSerializer.java:455)
	at org.bitcoinj.wallet.Wallet.loadFromFileStream(Wallet.java:2076)
	at org.bitcoinj.wallet.Wallet.loadFromFile(Wallet.java:1961)
	at org.bitcoinj.kits.WalletAppKit.loadWallet(WalletAppKit.java:508)
	at org.bitcoinj.kits.WalletAppKit.createOrLoadWallet(WalletAppKit.java:480)
	at org.bitcoinj.kits.WalletAppKit.startUp(WalletAppKit.java:399)
	at com.google.common.util.concurrent.AbstractIdleService$DelegateService.lambda$doStart$0(AbstractIdleService.java:64)
	at com.google.common.util.concurrent.Callables.lambda$threadRenaming$3(Callables.java:105)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.IllegalStateException: You must construct a Context object before using bitcoinj!
	at org.bitcoinj.core.Context.get(Context.java:124)
	at org.bitcoinj.core.Transaction.getConfidence(Transaction.java:1586)
	at org.bitcoinj.wallet.WalletProtobufSerializer.connectTransactionOutputs(WalletProtobufSerializer.java:771)
	at org.bitcoinj.wallet.WalletProtobufSerializer.readWallet(WalletProtobufSerializer.java:551)
	at org.bitcoinj.wallet.WalletProtobufSerializer.readWallet(WalletProtobufSerializer.java:453)
	... 8 more

当出现以上异常时，需要在钱包加载(WalletAppKit.launch)前，设置:Context.propagate(new Context()); 如下所示：

        BitcoinNetwork network = BitcoinNetwork.TESTNET;
        Context.propagate(new Context()); // 这里必须要设置，否则会出现加载钱包错误

        // Initialize and start a WalletAppKit. The kit handles all the boilerplate for us and is the easiest way to get everything up and running.
        // Look at the WalletAppKit documentation and its source to understand what's happening behind the scenes: https://github.com/bitcoinj/bitcoinj/blob/master/core/src/main/java/org/bitcoinj/kits/WalletAppKit.java
        // WalletAppKit extends the Guava AbstractIdleService. Have a look at the introduction to Guava services: https://github.com/google/guava/wiki/ServiceExplained
        WalletAppKit kit = WalletAppKit.launch(network, new File("."), "walletappkit-example", (k) -> {
            // In case you want to connect with your local bitcoind tell the kit to connect to localhost.
            // This is done automatically in reg test mode.
            // k.connectToLocalHost();
            try {
                k.setPeerNodes(PeerAddress.simple(InetAddress.getByName("127.0.0.1"), 18333));
            } catch (UnknownHostException e) {
                e.printStackTrace();
            }
        });

2.节点连接异常

WARN  [NioClientManager] [o.b.n.ConnectionHandler](ConnectionHandler.java:251) Error handling SelectionKey: java.nio.channels.CancelledKeyException 
java.nio.channels.CancelledKeyException: null
	at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:73)
	at sun.nio.ch.SelectionKeyImpl.readyOps(SelectionKeyImpl.java:87)
	at java.nio.channels.SelectionKey.isWritable(SelectionKey.java:312)
	at org.bitcoinj.net.ConnectionHandler.handleKey(ConnectionHandler.java:245)
	at org.bitcoinj.net.NioClientManager.handleKey(NioClientManager.java:97)
	at org.bitcoinj.net.NioClientManager.run(NioClientManager.java:133)
	at com.google.common.util.concurrent.AbstractExecutionThreadService$1.lambda$doStart$1(AbstractExecutionThreadService.java:57)
	at com.google.common.util.concurrent.Callables.lambda$threadRenaming$3(Callables.java:105)
	at org.bitcoinj.utils.ContextPropagatingThreadFactory.lambda$newThread$0(ContextPropagatingThreadFactory.java:49)
	at java.lang.Thread.run(Thread.java:750)
2024-03-21 09:56:53.609 INFO  [PeerGroup Thread] [o.b.c.PeerGroup](PeerGroup.java:639) Waiting 1500 ms before next connect attempt to [127.0.0.1]:18333

这种情况，一般是因为默认选用了测试网的公开节点，请求被限频。可以参考上面部署单个节点来解决，但必须设置_peerbloomfilters=1，bitcoinj只能连接支持bloom filter的节点。_