import com.google.bitcoin.wallet.AllowUnconfirmedCoinSelector; //导入依赖的package包/类
/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getMultisigContract()}. The way the contract is crafted can be adjusted by
 * overriding {@link PaymentChannelClientState#editContractSendRequest(com.google.bitcoin.core.Wallet.SendRequest)}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 *
 * @throws ValueOutOfRangeException if the value being used is too small to be accepted by the network
 * @throws InsufficientMoneyException if the wallet doesn't contain enough balance to initiate
 */
public synchronized void initiate() throws ValueOutOfRangeException, InsufficientMoneyException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // We always place the client key before the server key because, if either side wants some privacy, they can
    // use a fresh key for the the multisig contract and nowhere else
    List<ECKey> keys = Lists.newArrayList(myKey, serverMultisigKey);
    // There is also probably a change output, but we don't bother shuffling them as it's obvious from the
    // format which one is the change. If we start obfuscating the change output better in future this may
    // be worth revisiting.
    TransactionOutput multisigOutput = template.addOutput(totalValue, ScriptBuilder.createMultiSigOutputScript(2, keys));
    if (multisigOutput.getMinNonDustValue().compareTo(totalValue) > 0)
        throw new ValueOutOfRangeException("totalValue too small to use");
    Wallet.SendRequest req = Wallet.SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    editContractSendRequest(req);
    wallet.completeTx(req);
    BigInteger multisigFee = req.fee;
    multisigContract = req.tx;
    // Build a refund transaction that protects us in the case of a bad server that's just trying to cause havoc
    // by locking up peoples money (perhaps as a precursor to a ransom attempt). We time lock it so the server
    // has an assurance that we cannot take back our money by claiming a refund before the channel closes - this
    // relies on the fact that since Bitcoin 0.8 time locked transactions are non-final. This will need to change
    // in future as it breaks the intended design of timelocking/tx replacement, but for now it simplifies this
    // specific protocol somewhat.
    refundTx = new Transaction(params);
    refundTx.addInput(multisigOutput).setSequenceNumber(0);   // Allow replacement when it's eventually reactivated.
    refundTx.setLockTime(expiryTime);
    if (totalValue.compareTo(Utils.CENT) < 0) {
        // Must pay min fee.
        final BigInteger valueAfterFee = totalValue.subtract(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
        if (Transaction.MIN_NONDUST_OUTPUT.compareTo(valueAfterFee) > 0)
            throw new ValueOutOfRangeException("totalValue too small to use");
        refundTx.addOutput(valueAfterFee, myKey.toAddress(params));
        refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
    } else {
        refundTx.addOutput(totalValue, myKey.toAddress(params));
        refundFees = multisigFee;
    }
    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with multi-sig contract {}, refund {}", multisigContract.getHashAsString(),
            refundTx.getHashAsString());
    state = State.INITIATED;
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

import com.google.bitcoin.wallet.AllowUnconfirmedCoinSelector; //导入依赖的package包/类
/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getMultisigContract()}. The way the contract is crafted can be adjusted by
 * overriding {@link PaymentChannelClientState#editContractSendRequest(com.google.bitcoin.core.Wallet.SendRequest)}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 *
 * @throws ValueOutOfRangeException if the value being used is too small to be accepted by the network
 * @throws InsufficientMoneyException if the wallet doesn't contain enough balance to initiate
 */
public synchronized void initiate() throws ValueOutOfRangeException, InsufficientMoneyException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // We always place the client key before the server key because, if either side wants some privacy, they can
    // use a fresh key for the the multisig contract and nowhere else
    List<ECKey> keys = Lists.newArrayList(myKey, serverMultisigKey);
    // There is also probably a change output, but we don't bother shuffling them as it's obvious from the
    // format which one is the change. If we start obfuscating the change output better in future this may
    // be worth revisiting.
    TransactionOutput multisigOutput = template.addOutput(totalValue, ScriptBuilder.createMultiSigOutputScript(2, keys));
    if (multisigOutput.getMinNonDustValue().compareTo(totalValue) > 0)
        throw new ValueOutOfRangeException("totalValue too small to use");
    Wallet.SendRequest req = Wallet.SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    editContractSendRequest(req);
    try {
        wallet.completeTx(req);
    } catch (CSExceptions.CannotEncode ex) {
        java.util.logging.Logger.getLogger(PaymentChannelClientState.class.getName()).log(Level.SEVERE, null, ex);
    }
    BigInteger multisigFee = req.fee;
    multisigContract = req.tx;
    // Build a refund transaction that protects us in the case of a bad server that's just trying to cause havoc
    // by locking up peoples money (perhaps as a precursor to a ransom attempt). We time lock it so the server
    // has an assurance that we cannot take back our money by claiming a refund before the channel closes - this
    // relies on the fact that since Bitcoin 0.8 time locked transactions are non-final. This will need to change
    // in future as it breaks the intended design of timelocking/tx replacement, but for now it simplifies this
    // specific protocol somewhat.
    refundTx = new Transaction(params);
    refundTx.addInput(multisigOutput).setSequenceNumber(0);   // Allow replacement when it's eventually reactivated.
    refundTx.setLockTime(expiryTime);
    if (totalValue.compareTo(Utils.CENT) < 0) {
        // Must pay min fee.
        final BigInteger valueAfterFee = totalValue.subtract(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
        if (Transaction.MIN_NONDUST_OUTPUT.compareTo(valueAfterFee) > 0)
            throw new ValueOutOfRangeException("totalValue too small to use");
        refundTx.addOutput(valueAfterFee, myKey.toAddress(params));
        refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
    } else {
        refundTx.addOutput(totalValue, myKey.toAddress(params));
        refundFees = multisigFee;
    }
    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with multi-sig contract {}, refund {}", multisigContract.getHashAsString(),
            refundTx.getHashAsString());
    state = State.INITIATED;
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

import com.google.bitcoin.wallet.AllowUnconfirmedCoinSelector; //导入依赖的package包/类
/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getMultisigContract()}. The way the contract is crafted can be adjusted by
 * overriding {@link PaymentChannelClientState#editContractSendRequest(com.google.bitcoin.core.Wallet.SendRequest)}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 *
 * @throws ValueOutOfRangeException If the value being used cannot be afforded or is too small to be accepted by the network
 */
public synchronized void initiate() throws ValueOutOfRangeException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // We always place the client key before the server key because, if either side wants some privacy, they can
    // use a fresh key for the the multisig contract and nowhere else
    List<ECKey> keys = Lists.newArrayList(myKey, serverMultisigKey);
    // There is also probably a change output, but we don't bother shuffling them as it's obvious from the
    // format which one is the change. If we start obfuscating the change output better in future this may
    // be worth revisiting.
    TransactionOutput multisigOutput = template.addOutput(totalValue, ScriptBuilder.createMultiSigOutputScript(2, keys));
    if (multisigOutput.getMinNonDustValue().compareTo(totalValue) > 0)
        throw new ValueOutOfRangeException("totalValue too small to use");
    Wallet.SendRequest req = Wallet.SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    editContractSendRequest(req);
    if (!wallet.completeTx(req))
        throw new ValueOutOfRangeException("Cannot afford this channel");
    BigInteger multisigFee = req.fee;
    multisigContract = req.tx;
    // Build a refund transaction that protects us in the case of a bad server that's just trying to cause havoc
    // by locking up peoples money (perhaps as a precursor to a ransom attempt). We time lock it so the server
    // has an assurance that we cannot take back our money by claiming a refund before the channel closes - this
    // relies on the fact that since Bitcoin 0.8 time locked transactions are non-final. This will need to change
    // in future as it breaks the intended design of timelocking/tx replacement, but for now it simplifies this
    // specific protocol somewhat.
    refundTx = new Transaction(params);
    refundTx.addInput(multisigOutput).setSequenceNumber(0);   // Allow replacement when it's eventually reactivated.
    refundTx.setLockTime(expiryTime);
    if (totalValue.compareTo(Utils.CENT) < 0) {
        // Must pay min fee.
        final BigInteger valueAfterFee = totalValue.subtract(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
        if (Transaction.MIN_NONDUST_OUTPUT.compareTo(valueAfterFee) > 0)
            throw new ValueOutOfRangeException("totalValue too small to use");
        refundTx.addOutput(valueAfterFee, myKey.toAddress(params));
        refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
    } else {
        refundTx.addOutput(totalValue, myKey.toAddress(params));
        refundFees = multisigFee;
    }
    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with multi-sig contract {}, refund {}", multisigContract.getHashAsString(),
            refundTx.getHashAsString());
    state = State.INITIATED;
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}