protected Collection<TransactionOutputEx> getSpendableOutputs() {
    Collection<TransactionOutputEx> list = _backing.getAllUnspentOutputs();

    // Prune confirmed outputs for coinbase outputs that are not old enough
    // for spending. Also prune unconfirmed receiving coins except for change
    int blockChainHeight = getBlockChainHeight();
    Iterator<TransactionOutputEx> it = list.iterator();
    while (it.hasNext()) {
      TransactionOutputEx output = it.next();
      if (output.isCoinBase) {
        int confirmations = blockChainHeight - output.height;
        if (confirmations < COINBASE_MIN_CONFIRMATIONS) {
          it.remove();
          continue;
        }
      }
      // Unless we allow zero confirmation spending we prune all unconfirmed outputs sent from
      // foreign addresses
      if (!_allowZeroConfSpending) {
        if (output.height == -1 && !isFromMe(output.outPoint.hash)) {
          // Prune receiving coins that is not change sent to ourselves
          it.remove();
        }
      }
    }
    return list;
  }
  /**
   * Broadcast outgoing transactions.
   *
   * <p>This method should only be called from the wallet manager
   *
   * @return false if synchronization failed due to failed blockchain connection
   */
  public synchronized boolean broadcastOutgoingTransactions() {
    checkNotArchived();
    List<Sha256Hash> broadcastedIds = new LinkedList<Sha256Hash>();
    Map<Sha256Hash, byte[]> transactions = _backing.getOutgoingTransactions();

    for (byte[] rawTransaction : transactions.values()) {
      TransactionEx tex = TransactionEx.fromUnconfirmedTransaction(rawTransaction);

      BroadcastResult result = broadcastTransaction(TransactionEx.toTransaction(tex));
      if (result == BroadcastResult.SUCCESS) {
        broadcastedIds.add(tex.txid);
        _backing.removeOutgoingTransaction(tex.txid);
      } else {
        if (result == BroadcastResult.REJECTED) {
          // invalid tx
          _backing.deleteTransaction(tex.txid);
          _backing.removeOutgoingTransaction(tex.txid);
        } else {
          // No connection --> retry next sync
        }
      }
    }
    if (!broadcastedIds.isEmpty()) {
      onTransactionsBroadcasted(broadcastedIds);
    }
    return true;
  }
  @Override
  public TransactionDetails getTransactionDetails(Sha256Hash txid) {
    // Note that this method is not synchronized, and we might fetch the transaction history while
    // synchronizing
    // accounts. That should be ok as we write to the DB in a sane order.

    TransactionEx tex = _backing.getTransaction(txid);
    Transaction tx = TransactionEx.toTransaction(tex);
    if (tx == null) {
      throw new RuntimeException();
    }

    List<TransactionDetails.Item> inputs = new ArrayList<TransactionDetails.Item>(tx.inputs.length);
    if (tx.isCoinbase()) {
      // We have a coinbase transaction. Create one input with the sum of the outputs as its value,
      // and make the address the null address
      long value = 0;
      for (TransactionOutput out : tx.outputs) {
        value += out.value;
      }
      inputs.add(new TransactionDetails.Item(Address.getNullAddress(_network), value, true));
    } else {
      // Populate the inputs
      for (TransactionInput input : tx.inputs) {
        Sha256Hash parentHash = input.outPoint.hash;
        // Get the parent transaction
        TransactionOutputEx parentOutput = _backing.getParentTransactionOutput(input.outPoint);
        if (parentOutput == null) {
          // We never heard about the parent, skip
          continue;
        }
        // Determine the parent address
        Address parentAddress;
        ScriptOutput parentScript = ScriptOutput.fromScriptBytes(parentOutput.script);
        if (parentScript == null) {
          // Null address means we couldn't figure out the address, strange script
          parentAddress = Address.getNullAddress(_network);
        } else {
          parentAddress = parentScript.getAddress(_network);
        }
        inputs.add(new TransactionDetails.Item(parentAddress, parentOutput.value, false));
      }
    }
    // Populate the outputs
    TransactionDetails.Item[] outputs = new TransactionDetails.Item[tx.outputs.length];
    for (int i = 0; i < tx.outputs.length; i++) {
      Address address = tx.outputs[i].script.getAddress(_network);
      outputs[i] = new TransactionDetails.Item(address, tx.outputs[i].value, false);
    }

    return new TransactionDetails(
        txid, tex.height, tex.time, inputs.toArray(new TransactionDetails.Item[] {}), outputs);
  }
  protected TransactionSummary transform(
      Transaction tx, int time, int height, int blockChainHeight) {
    long value = 0;
    Address destAddress = null;
    for (TransactionOutput output : tx.outputs) {
      if (isMine(output.script)) {
        value += output.value;
      } else {
        destAddress = output.script.getAddress(_network);
      }
    }

    if (tx.isCoinbase()) {
      // For coinbase transactions there is nothing to subtract
    } else {
      for (TransactionInput input : tx.inputs) {
        // find parent output
        TransactionOutputEx funding = _backing.getParentTransactionOutput(input.outPoint);
        if (funding == null) {
          _logger.logError("Unable to find parent output for: " + input.outPoint);
          continue;
        }
        if (isMine(funding)) {
          value -= funding.value;
        }
      }
    }

    int confirmations;
    if (height == -1) {
      confirmations = 0;
    } else {
      confirmations = Math.max(0, blockChainHeight - height + 1);
    }

    // only track a destinationAddress if it is an outgoing transaction (i.e. send money to someone)
    // to prevent the user that he tries to return money to an address he got bitcoin from.
    if (value >= 0) {
      destAddress = null;
    }

    boolean isQueuedOutgoing = _backing.isOutgoingTransaction(tx.getHash());

    return new TransactionSummary(
        tx.getHash(),
        value,
        time,
        height,
        confirmations,
        isQueuedOutgoing,
        com.google.common.base.Optional.fromNullable(destAddress));
  }
  private void handleNewExternalTransactionsInt(Collection<TransactionEx> transactions)
      throws WapiException {
    // Transform and put into two arrays with matching indexes
    ArrayList<TransactionEx> texArray = new ArrayList<TransactionEx>(transactions.size());
    ArrayList<Transaction> txArray = new ArrayList<Transaction>(transactions.size());
    for (TransactionEx tex : transactions) {
      try {
        txArray.add(Transaction.fromByteReader(new ByteReader(tex.binary)));
        texArray.add(tex);
      } catch (TransactionParsingException e) {
        // We hit a transaction that we cannot parse. Log but otherwise ignore it
        _logger.logError("Received transaction that we cannot parse: " + tex.txid.toString());
        continue;
      }
    }

    // Grab and handle parent transactions
    fetchStoreAndValidateParentOutputs(txArray);

    // Store transaction locally
    for (int i = 0; i < txArray.size(); i++) {
      _backing.putTransaction(texArray.get(i));
      onNewTransaction(texArray.get(i), txArray.get(i));
    }
  }
 /**
  * Determine whether a transaction was sent from one of our own addresses.
  *
  * <p>This is a costly operation as we first have to lookup the transaction and then it's funding
  * outputs
  *
  * @param txid the ID of the transaction to investigate
  * @return true if one of the funding outputs were sent from one of our own addresses
  */
 protected boolean isFromMe(Sha256Hash txid) {
   Transaction t = TransactionEx.toTransaction(_backing.getTransaction(txid));
   if (t == null) {
     return false;
   }
   return isFromMe(t);
 }
 public synchronized void queueTransaction(Transaction transaction) {
   // Store transaction in outgoing buffer, so we can broadcast it
   // later
   byte[] rawTransaction = transaction.toBytes();
   _backing.putOutgoingTransaction(transaction.getHash(), rawTransaction);
   markTransactionAsSpent(transaction);
 }
 @Override
 public synchronized boolean deleteTransaction(Sha256Hash transactionId) {
   TransactionEx tex = _backing.getTransaction(transactionId);
   if (tex == null) return false;
   Transaction tx = TransactionEx.toTransaction(tex);
   _backing.beginTransaction();
   try {
     // See if any of the outputs are stored locally and remove them
     for (int i = 0; i < tx.outputs.length; i++) {
       TransactionOutput output = tx.outputs[i];
       OutPoint outPoint = new OutPoint(tx.getHash(), i);
       TransactionOutputEx utxo = _backing.getUnspentOutput(outPoint);
       if (utxo != null) {
         _backing.deleteUnspentOutput(outPoint);
       }
     }
     // remove it from the backing
     _backing.deleteTransaction(transactionId);
     _backing.setTransactionSuccessful();
   } finally {
     _backing.endTransaction();
   }
   updateLocalBalance(); // will still need a new sync besides re-calculating
   return true;
 }
  protected boolean monitorYoungTransactions() {
    Collection<TransactionEx> list = _backing.getYoungTransactions(5, getBlockChainHeight());
    if (list.isEmpty()) {
      return true;
    }
    List<Sha256Hash> txids = new ArrayList<Sha256Hash>(list.size());
    for (TransactionEx tex : list) {
      txids.add(tex.txid);
    }
    CheckTransactionsResponse result;
    try {
      result = _wapi.checkTransactions(new CheckTransactionsRequest(txids)).getResult();
    } catch (WapiException e) {
      postEvent(Event.SERVER_CONNECTION_ERROR);
      _logger.logError("Server connection failed with error code: " + e.errorCode, e);
      // We failed to check transactions
      return false;
    }
    for (TransactionStatus t : result.transactions) {
      if (!t.found) {
        // We have a transaction locally that does not exist in the
        // blockchain. Must be a residue due to double-spend or malleability

        _backing.deleteTransaction(t.txid);
        continue;
      }
      TransactionEx tex = _backing.getTransaction(t.txid);
      Preconditions.checkNotNull(tex);
      if (tex.height != t.height || tex.time != t.time) {
        // The transaction got a new height or timestamp. There could be
        // several reasons for that. It got a new timestamp from the server,
        // it confirmed, or might also be a reorg.
        TransactionEx newTex = new TransactionEx(tex.txid, t.height, t.time, tex.binary);
        System.out.println("Replacing:\n" + tex.toString() + "\nWith:\n" + newTex.toString());
        postEvent(Event.TRANSACTION_HISTORY_CHANGED);
        _backing.deleteTransaction(tex.txid);
        _backing.putTransaction(newTex);
      }
    }
    return true;
  }
 /**
  * Determine whether a transaction was sent from one of our own addresses.
  *
  * <p>This is a costly operation as we have to lookup funding outputs of the transaction
  *
  * @param t the transaction to investigate
  * @return true iff one of the funding outputs were sent from one of our own addresses
  */
 protected boolean isFromMe(Transaction t) {
   for (TransactionInput input : t.inputs) {
     TransactionOutputEx funding = _backing.getParentTransactionOutput(input.outPoint);
     if (funding == null || funding.isCoinBase) {
       continue;
     }
     ScriptOutput fundingScript = ScriptOutput.fromScriptBytes(funding.script);
     Address fundingAddress = fundingScript.getAddress(_network);
     if (isMine(fundingAddress)) {
       return true;
     }
   }
   return false;
 }
  @Override
  public synchronized boolean cancelQueuedTransaction(Sha256Hash transaction) {
    Map<Sha256Hash, byte[]> outgoingTransactions = _backing.getOutgoingTransactions();

    if (!outgoingTransactions.containsKey(transaction)) {
      return false;
    }

    Transaction tx;
    try {
      tx = Transaction.fromBytes(outgoingTransactions.get(transaction));
    } catch (TransactionParsingException e) {
      return false;
    }

    _backing.beginTransaction();
    try {

      // See if any of the outputs are stored locally and remove them
      for (int i = 0; i < tx.outputs.length; i++) {
        TransactionOutput output = tx.outputs[i];
        OutPoint outPoint = new OutPoint(tx.getHash(), i);
        TransactionOutputEx utxo = _backing.getUnspentOutput(outPoint);
        if (utxo != null) {
          _backing.deleteUnspentOutput(outPoint);
        }
      }

      // Remove a queued transaction from our outgoing buffer
      _backing.removeOutgoingTransaction(transaction);

      // remove it from the backing
      _backing.deleteTransaction(transaction);
      _backing.setTransactionSuccessful();
    } finally {
      _backing.endTransaction();
    }

    // calc the new balance to remove the outgoing amount
    // the total balance will still be wrong, as we already deleted some UTXOs to build the queued
    // transaction
    // these will get restored after the next sync
    updateLocalBalance();

    // markTransactionAsSpent(transaction);
    return true;
  }
  private void markTransactionAsSpent(Transaction transaction) {
    _backing.beginTransaction();
    try {
      // Remove inputs from unspent, marking them as spent
      for (TransactionInput input : transaction.inputs) {
        TransactionOutputEx parentOutput = _backing.getUnspentOutput(input.outPoint);
        if (parentOutput != null) {
          _backing.deleteUnspentOutput(input.outPoint);
          _backing.putParentTransactionOutput(parentOutput);
        }
      }

      // See if any of the outputs are for ourselves and store them as
      // unspent
      for (int i = 0; i < transaction.outputs.length; i++) {
        TransactionOutput output = transaction.outputs[i];
        if (isMine(output.script)) {
          _backing.putUnspentOutput(
              new TransactionOutputEx(
                  new OutPoint(transaction.getHash(), i),
                  -1,
                  output.value,
                  output.script.getScriptBytes(),
                  false));
        }
      }

      // Store transaction locally, so we have it in our history and don't
      // need to fetch it in a minute
      _backing.putTransaction(TransactionEx.fromUnconfirmedTransaction(transaction));
      _backing.setTransactionSuccessful();
    } finally {
      _backing.endTransaction();
    }

    // Tell account that we have a new transaction
    onNewTransaction(TransactionEx.fromUnconfirmedTransaction(transaction), transaction);

    // Calculate local balance cache. It has changed because we have done
    // some spending
    updateLocalBalance();
    persistContextIfNecessary();
  }
  @Override
  public List<TransactionSummary> getTransactionHistory(int offset, int limit) {
    // Note that this method is not synchronized, and we might fetch the transaction history while
    // synchronizing
    // accounts. That should be ok as we write to the DB in a sane order.

    List<TransactionSummary> history = new ArrayList<TransactionSummary>();
    checkNotArchived();
    int blockChainHeight = getBlockChainHeight();
    List<TransactionEx> list = _backing.getTransactionHistory(offset, limit);
    for (TransactionEx tex : list) {
      TransactionSummary item = transform(tex, blockChainHeight);
      if (item != null) {
        history.add(item);
      }
    }
    return history;
  }
  @Override
  public List<TransactionOutputSummary> getUnspentTransactionOutputSummary() {
    // Note that this method is not synchronized, and we might fetch the transaction history while
    // synchronizing
    // accounts. That should be ok as we write to the DB in a sane order.

    // Get all unspent outputs for this account
    Collection<TransactionOutputEx> outputs = _backing.getAllUnspentOutputs();

    // Transform it to a list of summaries
    List<TransactionOutputSummary> list = new ArrayList<TransactionOutputSummary>();
    int blockChainHeight = getBlockChainHeight();
    for (TransactionOutputEx output : outputs) {

      ScriptOutput script = ScriptOutput.fromScriptBytes(output.script);
      Address address;
      if (script == null) {
        address = Address.getNullAddress(_network);
        // This never happens as we have parsed this script before
      } else {
        address = script.getAddress(_network);
      }
      int confirmations;
      if (output.height == -1) {
        confirmations = 0;
      } else {
        confirmations = Math.max(0, blockChainHeight - output.height + 1);
      }

      TransactionOutputSummary summary =
          new TransactionOutputSummary(
              output.outPoint, output.value, output.height, confirmations, address);
      list.add(summary);
    }
    // Sort & return
    Collections.sort(list);
    return list;
  }
  protected Balance calculateLocalBalance() {

    Collection<TransactionOutputEx> unspentOutputs =
        new HashSet<TransactionOutputEx>(_backing.getAllUnspentOutputs());
    long confirmed = 0;
    long pendingChange = 0;
    long pendingSending = 0;
    long pendingReceiving = 0;

    //
    // Determine the value we are receiving and create a set of outpoints for fast lookup
    //
    Set<OutPoint> unspentOutPoints = new HashSet<OutPoint>();
    for (TransactionOutputEx output : unspentOutputs) {
      if (output.height == -1) {
        if (isFromMe(output.outPoint.hash)) {
          pendingChange += output.value;
        } else {
          pendingReceiving += output.value;
        }
      } else {
        confirmed += output.value;
      }
      unspentOutPoints.add(output.outPoint);
    }

    //
    // Determine the value we are sending
    //

    // Get the current set of unconfirmed transactions
    List<Transaction> unconfirmed = new ArrayList<Transaction>();
    for (TransactionEx tex : _backing.getUnconfirmedTransactions()) {
      try {
        Transaction t = Transaction.fromByteReader(new ByteReader(tex.binary));
        unconfirmed.add(t);
      } catch (TransactionParsingException e) {
        // never happens, we have parsed it before
      }
    }

    for (Transaction t : unconfirmed) {
      // For each input figure out if WE are sending it by fetching the
      // parent transaction and looking at the address
      boolean weSend = false;
      for (TransactionInput input : t.inputs) {
        // Find the parent transaction
        if (input.outPoint.hash.equals(Sha256Hash.ZERO_HASH)) {
          continue;
        }
        TransactionOutputEx parent = _backing.getParentTransactionOutput(input.outPoint);
        if (parent == null) {
          _logger.logError("Unable to find parent transaction output: " + input.outPoint);
          continue;
        }
        TransactionOutput parentOutput = transform(parent);
        Address fundingAddress = parentOutput.script.getAddress(_network);
        if (isMine(fundingAddress)) {
          // One of our addresses are sending coins
          pendingSending += parentOutput.value;
          weSend = true;
        }
      }

      // Now look at the outputs and if it contains change for us, then subtract that from the
      // sending amount
      // if it is already spent in another transaction
      for (int i = 0; i < t.outputs.length; i++) {
        TransactionOutput output = t.outputs[i];
        Address destination = output.script.getAddress(_network);
        if (weSend && isMine(destination)) {
          // The funds are sent from us to us
          OutPoint outPoint = new OutPoint(t.getHash(), i);
          if (!unspentOutPoints.contains(outPoint)) {
            // This output has been spent, subtract it from the amount sent
            pendingSending -= output.value;
          }
        }
      }
    }

    int blockHeight = getBlockChainHeight();
    return new Balance(
        confirmed,
        pendingReceiving,
        pendingSending,
        pendingChange,
        System.currentTimeMillis(),
        blockHeight,
        true,
        _allowZeroConfSpending);
  }
 @Override
 public TransactionSummary getTransactionSummary(Sha256Hash txid) {
   TransactionEx tx = _backing.getTransaction(txid);
   return transform(tx, tx.height);
 }
  private void fetchStoreAndValidateParentOutputs(ArrayList<Transaction> transactions)
      throws WapiException {
    Map<Sha256Hash, TransactionEx> parentTransactions = new HashMap<Sha256Hash, TransactionEx>();
    Map<OutPoint, TransactionOutputEx> parentOutputs = new HashMap<OutPoint, TransactionOutputEx>();

    // Find list of parent outputs to fetch
    Collection<Sha256Hash> toFetch = new HashSet<Sha256Hash>();
    for (Transaction t : transactions) {
      for (TransactionInput in : t.inputs) {
        if (in.outPoint.hash.equals(OutPoint.COINBASE_OUTPOINT.hash)) {
          // Coinbase input, so no parent
          continue;
        }
        TransactionOutputEx parentOutput = _backing.getParentTransactionOutput(in.outPoint);
        if (parentOutput != null) {
          // We already have the parent output, no need to fetch the entire
          // parent transaction
          parentOutputs.put(parentOutput.outPoint, parentOutput);
          continue;
        }
        TransactionEx parentTransaction = _backing.getTransaction(in.outPoint.hash);
        if (parentTransaction != null) {
          // We had the parent transaction in our own transactions, no need to
          // fetch it remotely
          parentTransactions.put(parentTransaction.txid, parentTransaction);
        } else {
          // Need to fetch it
          toFetch.add(in.outPoint.hash);
        }
      }
    }

    // Fetch missing parent transactions
    if (toFetch.size() > 0) {
      GetTransactionsResponse result =
          _wapi.getTransactions(new GetTransactionsRequest(Wapi.VERSION, toFetch)).getResult();
      for (TransactionEx tx : result.transactions) {
        // Verify transaction hash. This is important as we don't want to
        // have a transaction output associated with an outpoint that
        // doesn't match.
        // This is the end users protection against a rogue server that lies
        // about the value of an output and makes you pay a large fee.
        Sha256Hash hash = HashUtils.doubleSha256(tx.binary).reverse();
        if (hash.equals(tx.txid)) {
          parentTransactions.put(tx.txid, tx);
        } else {
          _logger.logError(
              "Failed to validate transaction hash from server. Expected: "
                  + tx.txid
                  + " Calculated: "
                  + hash);
          throw new RuntimeException(
              "Failed to validate transaction hash from server. Expected: "
                  + tx.txid
                  + " Calculated: "
                  + hash);
        }
      }
    }

    // We should now have all parent transactions or parent outputs. There is
    // a slight probability that one of them was not found due to double
    // spends and/or malleability and network latency etc.

    // Now figure out which parent outputs we need to persist
    List<TransactionOutputEx> toPersist = new LinkedList<TransactionOutputEx>();
    for (Transaction t : transactions) {
      for (TransactionInput in : t.inputs) {
        if (in.outPoint.hash.equals(OutPoint.COINBASE_OUTPOINT.hash)) {
          // coinbase input, so no parent
          continue;
        }
        TransactionOutputEx parentOutput = parentOutputs.get(in.outPoint);
        if (parentOutput != null) {
          // We had it all along
          continue;
        }
        TransactionEx parentTex = parentTransactions.get(in.outPoint.hash);
        if (parentTex != null) {
          // Parent output not found, maybe we already have it
          parentOutput = TransactionEx.getTransactionOutput(parentTex, in.outPoint.index);
          toPersist.add(parentOutput);
          continue;
        }
        _logger.logError("Parent transaction not found: " + in.outPoint.hash);
      }
    }

    // Persist
    for (TransactionOutputEx output : toPersist) {
      _backing.putParentTransactionOutput(output);
    }
  }
  protected boolean synchronizeUnspentOutputs(Collection<Address> addresses) {
    // Get the current unspent outputs as dictated by the block chain
    QueryUnspentOutputsResponse UnspentOutputResponse;
    try {
      UnspentOutputResponse =
          _wapi
              .queryUnspentOutputs(new QueryUnspentOutputsRequest(Wapi.VERSION, addresses))
              .getResult();
    } catch (WapiException e) {
      _logger.logError("Server connection failed with error code: " + e.errorCode, e);
      postEvent(Event.SERVER_CONNECTION_ERROR);
      return false;
    }
    Collection<TransactionOutputEx> remoteUnspent = UnspentOutputResponse.unspent;
    // Store the current block height
    setBlockChainHeight(UnspentOutputResponse.height);
    // Make a map for fast lookup
    Map<OutPoint, TransactionOutputEx> remoteMap = toMap(remoteUnspent);

    // Get the current unspent outputs as it is believed to be locally
    Collection<TransactionOutputEx> localUnspent = _backing.getAllUnspentOutputs();
    // Make a map for fast lookup
    Map<OutPoint, TransactionOutputEx> localMap = toMap(localUnspent);

    // Find remotely removed unspent outputs
    for (TransactionOutputEx l : localUnspent) {
      TransactionOutputEx r = remoteMap.get(l.outPoint);
      if (r == null) {
        // An output has gone. Maybe it was spent in another wallet, or
        // never confirmed due to missing fees, double spend, or mutated.
        // Either way, we delete it locally
        _backing.deleteUnspentOutput(l.outPoint);
      }
    }

    // Find remotely added unspent outputs
    Set<Sha256Hash> transactionsToAddOrUpdate = new HashSet<Sha256Hash>();
    List<TransactionOutputEx> unspentOutputsToAddOrUpdate = new LinkedList<TransactionOutputEx>();
    for (TransactionOutputEx r : remoteUnspent) {
      TransactionOutputEx l = localMap.get(r.outPoint);
      if (l == null || l.height != r.height) {
        // New remote output or new height (Maybe it confirmed or we
        // might even have had a reorg). Either way we just update it
        unspentOutputsToAddOrUpdate.add(r);
        transactionsToAddOrUpdate.add(r.outPoint.hash);
        // Note: We are not adding the unspent output to the DB just yet. We
        // first want to verify the full set of funding transactions of the
        // transaction that this unspent output belongs to
      }
    }

    // Fetch updated or added transactions
    if (transactionsToAddOrUpdate.size() > 0) {
      GetTransactionsResponse response;
      try {
        response =
            _wapi
                .getTransactions(
                    new GetTransactionsRequest(Wapi.VERSION, transactionsToAddOrUpdate))
                .getResult();
      } catch (WapiException e) {
        _logger.logError("Server connection failed with error code: " + e.errorCode, e);
        postEvent(Event.SERVER_CONNECTION_ERROR);
        return false;
      }
      try {
        handleNewExternalTransactions(response.transactions);
      } catch (WapiException e) {
        _logger.logError("Server connection failed with error code: " + e.errorCode, e);
        postEvent(Event.SERVER_CONNECTION_ERROR);
        return false;
      }
      // Finally update out list of unspent outputs with added or updated
      // outputs
      for (TransactionOutputEx output : unspentOutputsToAddOrUpdate) {
        _backing.putUnspentOutput(output);
      }
    }

    return true;
  }
 @Override
 public TransactionEx getTransaction(Sha256Hash txid) {
   return _backing.getTransaction(txid);
 }