Create Raw Transaction in BitcoinJ offline starting from UTXO info

Question

I would to create offline Raw Transaction (without signing it) in BitcoinJ. The information I know about the inout is UTXO's hash, index, amount, address, and script. I also know the receiver address of the final transaction, the change address, the amount and the fee.
I'm fighting with the TransactionOutput constructors to build the input for my transaction. I don't know where to set UTXO hash and index - i think in the "parent" parameter, but i'm failing. This is my snippet:
Transaction parent = ??? 
Coin value = Coin.valueOf(satoshi(utxo.getAmount()));
Address to = Address.fromBase58(params, utxo.getOwnerAddress());
//where do i put utxo hash and index?
TransactionOutput input = new TransactionOutput(params, parent, value, to);
tx.addInput(input)

fatdoor · Accepted Answer

I'm fighting with the TransactionOutput constructors to build the input for my transaction. I don't know where to set UTXO hash and index

I think you can build the input based on a previous transaction output (outpoint) as follows:
byte[] scriptBytes = {};
Sha256Hash vinTxId = Sha256Hash.wrap(txId);
TransactionOutPoint outpoint = new TransactionOutPoint(params, index, vinTxId);
Coin value = null;
TransactionInput input = new TransactionInput(params, transaction, scriptBytes, outpoint, value);
transaction.addInput(input);

Not sure if this is the best ways to do it.
EDIT: This does the same as the code above.
transaction.addInput(Sha256Hash.wrap(txId), index, ScriptBuilder.createEmpty());

Create Raw Transaction in BitcoinJ offline starting from UTXO info

One Answer

Add your own answers!

Ask a Question