btc、usdt 根据交易hash计算手续费

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业务场景：1.在自己的钱包节点上根据txId获取交易原始交易

** 2.通过原始交易递归计算手续费： 公式[ 手续费 sum(vin)- sum(vout) ]**

** 要求：需要对utxo有一定的了解~~~**

** blockchain:https://www.blockchain.com/btc/address/1NiRsrLA7WgNUQQNKfuz7nSx4eoKadXpNY**

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上面是用区块链浏览器查看交易txId 的交易明细，查看该原始交易为：

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由此根据交易hash从自己的节点进行查看原始交易并计算出类似区块链浏览器一致的信息：

//交易信息
public class BtcTransactionInfo implements Serializable {

    private static final long serialVersionUID = 1L;

    private String txId; //交易txid
    private String hash; //hash
    private String blockheight;//区块高度
    private String blockweight; //区块宽度
    private String blockconfirmations;//区块确认数
    private String blockversion;
    private String previousblockhash; //上一个区块的块hash
    private String nextblockhash; //下一个块hash
    private String version;
    private String size;
    private String vsize;
    private String locktime;
    private String hex; //hex
    private String blockhash;
    private String confirmations; //确认次数
    private String time;
    private String blocktime;
    private BigDecimal amount; //金额
    private BigDecimal free; //手续费
    private String from; //发送方
    private String to; //接收方

}

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通过JSON-rpc 进行节点的调用参考：https://blog.csdn.net/u011663149/article/details/87182097

//根据交易的txid调用钱包api获取相应信息
public Object getrawTransactionByTxIdFromWallet(String txId) throws Exception {
        BtcTransactionInfo  tranc = new BtcTransactionInfo();
        try {
            //调用原始交易接口
            Map transaction = (Map) btService.getTrawtransaction(txId, 1);
            JSONObject info = JSONObject.parseObject(JSON.toJSONString(transaction));
            String blockHash = info.getString("blockhash");
            /*block*/
            //调用根据blockhash 获取块信息接口
            Map blockInfo = (Map)btService.getblock(blockHash);
            JSONObject block = JSONObject.parseObject(JSON.toJSONString(blockInfo));
            tranc.setBlockconfirmations(block.getString("confirmations"));
            tranc.setBlocktime(block.getString("time"));
            tranc.setBlockversion(block.getString("version"));
            tranc.setBlockheight(block.getString("height"));
            tranc.setBlockweight(block.getString("weight"));
            tranc.setPreviousblockhash(block.getString("previousblockhash"));
            tranc.setNextblockhash(block.getString("nextblockhash"));

            tranc.setTxId(info.getString("txid"));
            tranc.setHash(info.getString("hash"));
            tranc.setVersion(info.getString("version"));
            tranc.setSize(info.getString("size"));
            tranc.setVsize(info.getString("vsize"));
            tranc.setLocktime(info.getString("locktime"));
            tranc.setHex(info.getString("hex"));
            tranc.setBlockhash(blockHash);
            tranc.setConfirmations(info.getString("confirmations"));
            tranc.setTime(info.getString("time"));
            tranc.setBlocktime(info.getString("blocktime"));

            JSONArray vins = JSONArray.parseArray(info.getString("vin"));
            double sumvin = 0 ;
            List<String> formAddress = new ArrayList<>();
            for (int i = 0,len = vins.size(); i < len; i++) {
                JSONObject vin =  JSONObject.parseObject(vins.getString(i));
                String txid = vin.getString("txid");
                Integer vinN = vin.getInteger("vout");
                LOG.info("=== [BTC] search txid:{} trawtransaction! ===",txid);
                Map parentTransaction = (Map) btService.getTrawtransaction(txid, 1);
                JSONObject parentInfo = JSONObject.parseObject(JSON.toJSONString(parentTransaction));
                JSONArray vouts = JSONArray.parseArray(parentInfo.getString("vout"));
                for (int j = 0,leg = vouts.size(); j < leg; j++) {
                    JSONObject vout = vouts.getJSONObject(j);
                    Integer n = vout.getInteger("n");
                    if(n == vinN){ //收款金额
                        sumvin += vout.getDouble("value");
                        JSONObject scriptPubKey = vout.getJSONObject("scriptPubKey");
                        JSONArray addresses = scriptPubKey.getJSONArray("addresses");
                        formAddress.add(addresses.getString(0));
                    }
                }
            }
            tranc.setFrom(StringUtils.strip(formAddress.toString(),"[]"));

            JSONArray vouts = JSONArray.parseArray(info.getString("vout"));
            BigDecimal amount = null  ;
            double sumvout = 0;

            for (int i = 0,len = vouts.size(); i < len; i++) {
                JSONObject vout =  JSONObject.parseObject(vouts.getString(i));
                Integer n = vout.getInteger("n");
                JSONObject scriptPubKey = vout.getJSONObject("scriptPubKey");
                JSONArray addresses = scriptPubKey.getJSONArray("addresses");
                String receviceAddr = addresses.getString(0);
                if(n == 0){
                    tranc.setTo(receviceAddr);
                    amount = new BigDecimal(vout.getDouble("value"));

                }
                 //找零金额
                    sumvout  +=  vout.getDouble("value");
            }
            //手续费  sum(vin)- sum(vout)
            tranc.setFree(new BigDecimal(sumvin).subtract(new BigDecimal(sumvout)).setScale(8, BigDecimal.ROUND_HALF_UP));
            tranc.setAmount(amount.setScale(8, BigDecimal.ROUND_HALF_UP));
        } catch (Exception e) {
            throw new Exception(e.getMessage());
        }

        return JSON.toJSON(tranc);
    }

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