Asset-related transactions API + performance improvements + fix

Moved as much reflection out to class-static initializers as possible.

Renamed some classes to fall in line with transaction type name
to class name conversion, e.g. DEPLOY_AT -> DeployAt

src/main/java/org/qora/api/resource/AssetsResource.java

@@ -29,6 +29,7 @@ import org.qora.api.ApiErrors;
 import org.qora.api.ApiException;
 import org.qora.api.ApiExceptionFactory;
 import org.qora.api.model.TradeWithOrderInfo;
+import org.qora.api.resource.TransactionsResource.ConfirmationStatus;
 import org.qora.crypto.Crypto;
 import org.qora.data.account.AccountBalanceData;
 import org.qora.data.account.AccountData;
@@ -38,6 +39,7 @@ import org.qora.data.asset.TradeData;
 import org.qora.data.transaction.CancelAssetOrderTransactionData;
 import org.qora.data.transaction.CreateAssetOrderTransactionData;
 import org.qora.data.transaction.IssueAssetTransactionData;
+import org.qora.data.transaction.TransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.repository.RepositoryManager;
@@ -482,6 +484,50 @@ public class AssetsResource {
 		}
 	}
 
+	@GET
+	@Path("/transactions/{assetid}")
+	@Operation(
+		summary = "Transactions related to asset",
+		responses = {
+			@ApiResponse(
+				description = "Asset transactions",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = TransactionData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.INVALID_ADDRESS, ApiError.INVALID_ASSET_ID, ApiError.REPOSITORY_ISSUE
+	})
+	public List<TransactionData> getAssetTransactions(@Parameter(
+		ref = "assetid"
+	) @PathParam("assetid") int assetId, @Parameter(
+		description = "whether to include confirmed, unconfirmed or both",
+		required = true
+	) @QueryParam("confirmationStatus") ConfirmationStatus confirmationStatus, @Parameter(
+		ref = "limit"
+	) @QueryParam("limit") Integer limit, @Parameter(
+		ref = "offset"
+	) @QueryParam("offset") Integer offset, @Parameter(
+		ref = "reverse"
+	) @QueryParam("reverse") Boolean reverse) {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			if (!repository.getAssetRepository().assetExists(assetId))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ASSET_ID);
+
+			return repository.getTransactionRepository().getAssetTransactions(assetId, confirmationStatus, limit, offset, reverse);
+		} catch (ApiException e) {
+			throw e;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 	@POST
 	@Path("/order/delete")
 	@Operation(

src/main/java/org/qora/repository/TransactionRepository.java

@@ -32,6 +32,18 @@ public interface TransactionRepository {
 	public List<byte[]> getSignaturesMatchingCriteria(Integer startBlock, Integer blockLimit, TransactionType txType, String address,
 			ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse) throws DataException;
 
+	/**
+	 * Returns list of transactions relating to specific asset ID.
+	 * 
+	 * @param assetId
+	 * @param limit
+	 * @param offset
+	 * @param reverse
+	 * @return list of transactions, or empty if none
+	 */
+	public List<TransactionData> getAssetTransactions(int assetId, ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse)
+			throws DataException;
+
 	/**
 	 * Returns list of unconfirmed transactions in timestamp-else-signature order.
 	 * <p>

src/main/java/org/qora/repository/hsqldb/HSQLDBSaver.java

@@ -5,8 +5,8 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Calendar;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -77,8 +77,7 @@ public class HSQLDBSaver {
 	 * @return String
 	 */
 	private String formatInsertWithPlaceholders() {
-		String[] placeholders = new String[this.columns.size()];
-		Arrays.setAll(placeholders, (int i) -> "?");
+		List<String> placeholders = Collections.nCopies(this.columns.size(), "?");
 
 		StringBuilder output = new StringBuilder();
 		output.append("INSERT INTO ");

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBAtTransactionRepository.java

@@ -10,9 +10,9 @@ import org.qora.repository.DataException;
 import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
 
-public class HSQLDBATTransactionRepository extends HSQLDBTransactionRepository {
+public class HSQLDBAtTransactionRepository extends HSQLDBTransactionRepository {
 
-	public HSQLDBATTransactionRepository(HSQLDBRepository repository) {
+	public HSQLDBAtTransactionRepository(HSQLDBRepository repository) {
 		this.repository = repository;
 	}
 

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBCancelAssetOrderTransactionRepository.java

@@ -10,9 +10,9 @@ import org.qora.repository.DataException;
 import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
 
-public class HSQLDBCancelOrderTransactionRepository extends HSQLDBTransactionRepository {
+public class HSQLDBCancelAssetOrderTransactionRepository extends HSQLDBTransactionRepository {
 
-	public HSQLDBCancelOrderTransactionRepository(HSQLDBRepository repository) {
+	public HSQLDBCancelAssetOrderTransactionRepository(HSQLDBRepository repository) {
 		this.repository = repository;
 	}
 

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBCreateAssetOrderTransactionRepository.java

@@ -10,9 +10,9 @@ import org.qora.repository.DataException;
 import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
 
-public class HSQLDBCreateOrderTransactionRepository extends HSQLDBTransactionRepository {
+public class HSQLDBCreateAssetOrderTransactionRepository extends HSQLDBTransactionRepository {
 
-	public HSQLDBCreateOrderTransactionRepository(HSQLDBRepository repository) {
+	public HSQLDBCreateAssetOrderTransactionRepository(HSQLDBRepository repository) {
 		this.repository = repository;
 	}
 

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBDeployAtTransactionRepository.java

@@ -10,9 +10,9 @@ import org.qora.repository.DataException;
 import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
 
-public class HSQLDBDeployATTransactionRepository extends HSQLDBTransactionRepository {
+public class HSQLDBDeployAtTransactionRepository extends HSQLDBTransactionRepository {
 
-	public HSQLDBDeployATTransactionRepository(HSQLDBRepository repository) {
+	public HSQLDBDeployAtTransactionRepository(HSQLDBRepository repository) {
 		this.repository = repository;
 	}
 

src/main/java/org/qora/repository/hsqldb/transaction/HSQLDBTransactionRepository.java

@@ -8,8 +8,10 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Calendar;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -22,45 +24,90 @@ import org.qora.repository.hsqldb.HSQLDBRepository;
 import org.qora.repository.hsqldb.HSQLDBSaver;
 import org.qora.transaction.Transaction.TransactionType;
 
+import static org.qora.transaction.Transaction.TransactionType.*;
+
 public class HSQLDBTransactionRepository implements TransactionRepository {
 
 	private static final Logger LOGGER = LogManager.getLogger(HSQLDBTransactionRepository.class);
 
+	public static class RepositorySubclassInfo {
+		public Class<?> clazz;
+		public Constructor<?> constructor;
+		public Method fromBaseMethod;
+		public Method saveMethod;
+	}
+
+	private static final RepositorySubclassInfo[] subclassInfos;
+	static {
+		subclassInfos = new RepositorySubclassInfo[TransactionType.values().length + 1];
+
+		for (TransactionType txType : TransactionType.values()) {
+			RepositorySubclassInfo subclassInfo = new RepositorySubclassInfo();
+
+			try {
+				subclassInfo.clazz = Class.forName(
+						String.join("", HSQLDBTransactionRepository.class.getPackage().getName(), ".", "HSQLDB", txType.className, "TransactionRepository"));
+			} catch (ClassNotFoundException e) {
+				LOGGER.debug(String.format("HSQLDBTransactionRepository subclass not found for transaction type \"%s\"", txType.name()));
+				continue;
+			}
+
+			try {
+				subclassInfo.constructor = subclassInfo.clazz.getConstructor(HSQLDBRepository.class);
+			} catch (NoSuchMethodException | IllegalArgumentException e) {
+				LOGGER.debug(String.format("HSQLDBTransactionRepository subclass constructor not found for transaction type \"%s\"", txType.name()));
+				continue;
+			}
+
+			try {
+				subclassInfo.fromBaseMethod = subclassInfo.clazz.getDeclaredMethod("fromBase", byte[].class, byte[].class, byte[].class, long.class,
+						BigDecimal.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("HSQLDBTransactionRepository subclass's \"fromBase\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			try {
+				subclassInfo.saveMethod = subclassInfo.clazz.getDeclaredMethod("save", TransactionData.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("HSQLDBTransactionRepository subclass's \"save\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			subclassInfos[txType.value] = subclassInfo;
+		}
+
+		LOGGER.trace("Static init reflection completed");
+	}
+
 	private HSQLDBTransactionRepository[] repositoryByTxType;
+
 	protected HSQLDBRepository repository;
 
 	public HSQLDBTransactionRepository(HSQLDBRepository repository) {
 		this.repository = repository;
 
-		this.repositoryByTxType = new HSQLDBTransactionRepository[256];
+		this.repositoryByTxType = new HSQLDBTransactionRepository[TransactionType.values().length + 1];
 
 		for (TransactionType txType : TransactionType.values()) {
-			Class<?> repositoryClass = getClassByTxType(txType);
-			if (repositoryClass == null)
+			RepositorySubclassInfo subclassInfo = subclassInfos[txType.value];
+
+			if (subclassInfo == null)
+				continue;
+
+			if (subclassInfo.constructor == null)
 				continue;
 
 			try {
-				Constructor<?> constructor = repositoryClass.getConstructor(HSQLDBRepository.class);
-				HSQLDBTransactionRepository txRepository = (HSQLDBTransactionRepository) constructor.newInstance(repository);
-				this.repositoryByTxType[txType.value] = txRepository;
-			} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | InstantiationException e) {
+				this.repositoryByTxType[txType.value] = (HSQLDBTransactionRepository) subclassInfo.constructor.newInstance(repository);
+			} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | InstantiationException e) {
 				continue;
 			}
 		}
 	}
 
+	// Never called
 	protected HSQLDBTransactionRepository() {
 	}
 
-	private static Class<?> getClassByTxType(TransactionType txType) {
-		try {
-			return Class.forName(
-					String.join("", HSQLDBTransactionRepository.class.getPackage().getName(), ".", "HSQLDB", txType.className, "TransactionRepository"));
-		} catch (ClassNotFoundException e) {
-			return null;
-		}
-	}
-
 	@Override
 	public TransactionData fromSignature(byte[] signature) throws DataException {
 		try (ResultSet resultSet = this.repository.checkedExecute("SELECT type, reference, creator, creation, fee FROM Transactions WHERE signature = ?",
@@ -132,9 +179,8 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 			throw new DataException("Unsupported transaction type [" + type.name() + "] during fetch from HSQLDB repository");
 
 		try {
-			Method method = txRepository.getClass().getDeclaredMethod("fromBase", byte[].class, byte[].class, byte[].class, long.class, BigDecimal.class);
-			return (TransactionData) method.invoke(txRepository, signature, reference, creatorPublicKey, timestamp, fee);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+			return (TransactionData) subclassInfos[type.value].fromBaseMethod.invoke(txRepository, signature, reference, creatorPublicKey, timestamp, fee);
+		} catch (IllegalArgumentException | InvocationTargetException | IllegalAccessException e) {
 			throw new DataException("Unsupported transaction type [" + type.name() + "] during fetch from HSQLDB repository");
 		}
 	}
@@ -343,6 +389,92 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		}
 	}
 
+	@Override
+	public List<TransactionData> getAssetTransactions(int assetId, ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse)
+			throws DataException {
+		TransactionType[] transactionTypes = new TransactionType[] {
+			ISSUE_ASSET, TRANSFER_ASSET, CREATE_ASSET_ORDER, CANCEL_ASSET_ORDER
+		};
+		List<String> typeValueStrings = Arrays.asList(transactionTypes).stream().map(type -> String.valueOf(type.value)).collect(Collectors.toList());
+
+		String sql = "SELECT Transactions.signature FROM Transactions";
+
+		// BlockTransactions if we want confirmed transactions
+		switch (confirmationStatus) {
+			case BOTH:
+				break;
+
+			case CONFIRMED:
+				sql += " JOIN BlockTransactions ON BlockTransactions.transaction_signature = Transactions.signature";
+				break;
+
+			case UNCONFIRMED:
+				sql += " LEFT OUTER JOIN BlockTransactions ON BlockTransactions.transaction_signature = Transactions.signature";
+				break;
+		}
+
+		for (TransactionType type : transactionTypes)
+			sql += " LEFT OUTER JOIN " + type.className + "Transactions USING (signature)";
+
+		// assetID isn't in Cancel Asset Order so we need to join to the order
+		sql += " LEFT OUTER JOIN AssetOrders ON AssetOrders.asset_order_id = CancelAssetOrderTransactions.asset_order_id";
+
+		sql += " WHERE Transactions.type IN (" + String.join(", ", typeValueStrings) + ")";
+
+		// BlockTransactions if we want confirmed transactions
+		switch (confirmationStatus) {
+			case BOTH:
+				break;
+
+			case CONFIRMED:
+				break;
+
+			case UNCONFIRMED:
+				sql += " AND BlockTransactions.transaction_signature IS NULL";
+				break;
+		}
+
+		sql += " AND (";
+		sql += "IssueAssetTransactions.asset_id = " + assetId;
+		sql += " OR ";
+		sql += "TransferAssetTransactions.asset_id = " + assetId;
+		sql += " OR ";
+		sql += "CreateAssetOrderTransactions.have_asset_id = " + assetId;
+		sql += " OR ";
+		sql += "CreateAssetOrderTransactions.want_asset_id = " + assetId;
+		sql += " OR ";
+		sql += "AssetOrders.have_asset_id = " + assetId;
+		sql += " OR ";
+		sql += "AssetOrders.want_asset_id = " + assetId;
+		sql += ") GROUP BY Transactions.signature, Transactions.creation ORDER BY Transactions.creation";
+
+		sql += (reverse == null || !reverse) ? " ASC" : " DESC";
+		sql += HSQLDBRepository.limitOffsetSql(limit, offset);
+
+		List<TransactionData> transactions = new ArrayList<TransactionData>();
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql)) {
+			if (resultSet == null)
+				return transactions;
+
+			do {
+				byte[] signature = resultSet.getBytes(1);
+
+				TransactionData transactionData = this.fromSignature(signature);
+
+				if (transactionData == null)
+					// Something inconsistent with the repository
+					throw new DataException("Unable to fetch asset-related transaction from repository?");
+
+				transactions.add(transactionData);
+			} while (resultSet.next());
+
+			return transactions;
+		} catch (SQLException | DataException e) {
+			throw new DataException("Unable to fetch asset-related transactions from repository", e);
+		}
+	}
+
 	@Override
 	public List<TransactionData> getUnconfirmedTransactions(Integer limit, Integer offset, Boolean reverse) throws DataException {
 		String sql = "SELECT signature FROM UnconfirmedTransactions ORDER BY creation";
@@ -417,9 +549,8 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 			throw new DataException("Unsupported transaction type [" + type.name() + "] during save into HSQLDB repository");
 
 		try {
-			Method method = txRepository.getClass().getDeclaredMethod("save", TransactionData.class);
-			method.invoke(txRepository, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+			subclassInfos[type.value].saveMethod.invoke(txRepository, transactionData);
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new DataException("Unsupported transaction type [" + type.name() + "] during save into HSQLDB repository");
 		}
 	}

src/main/java/org/qora/transaction/ATTransaction.java

@@ -15,7 +15,7 @@ import org.qora.data.transaction.TransactionData;
 import org.qora.repository.DataException;
 import org.qora.repository.Repository;
 import org.qora.transform.TransformationException;
-import org.qora.transform.transaction.ATTransactionTransformer;
+import org.qora.transform.transaction.AtTransactionTransformer;
 
 import com.google.common.primitives.Bytes;
 
@@ -38,7 +38,7 @@ public class ATTransaction extends Transaction {
 		if (this.atTransactionData.getSignature() == null) {
 			// Signature is SHA2-256 of serialized transaction data, duplicated to make standard signature size of 64 bytes.
 			try {
-				byte[] digest = Crypto.digest(ATTransactionTransformer.toBytes(transactionData));
+				byte[] digest = Crypto.digest(AtTransactionTransformer.toBytes(transactionData));
 				byte[] signature = Bytes.concat(digest, digest);
 				this.atTransactionData.setSignature(signature);
 			} catch (TransformationException e) {

src/main/java/org/qora/transaction/Transaction.java

@@ -35,6 +35,7 @@ public abstract class Transaction {
 
 	// Transaction types
 	public enum TransactionType {
+		// NOTE: must be contiguous or reflection fails
 		GENESIS(1),
 		PAYMENT(2),
 		REGISTER_NAME(3),
@@ -71,6 +72,8 @@ public abstract class Transaction {
 		public final int value;
 		public final String valueString;
 		public final String className;
+		public final Class<?> clazz;
+		public final Constructor<?> constructor;
 
 		private final static Map<Integer, TransactionType> map = stream(TransactionType.values()).collect(toMap(type -> type.value, type -> type));
 
@@ -84,6 +87,25 @@ public abstract class Transaction {
 				classNameParts[i] = classNameParts[i].substring(0, 1).toUpperCase().concat(classNameParts[i].substring(1));
 
 			this.className = String.join("", classNameParts);
+
+			Class<?> clazz = null;
+			try {
+				clazz = Class.forName(String.join("", Transaction.class.getPackage().getName(), ".", this.className, "Transaction"));
+			} catch (ClassNotFoundException e) {
+				LOGGER.debug(String.format("Transaction subclass not found for transaction type \"%s\"", this.name()));
+				this.clazz = null;
+				this.constructor = null;
+				return;
+			}
+			this.clazz = clazz;
+
+			Constructor<?> constructor = null;
+			try {
+				constructor = this.clazz.getConstructor(Repository.class, TransactionData.class);
+			} catch (NoSuchMethodException | SecurityException e) {
+				LOGGER.debug(String.format("Transaction subclass constructor not found for transaction type \"%s\"", this.name()));
+			}
+			this.constructor = constructor;
 		}
 
 		public static TransactionType valueOf(int value) {
@@ -91,14 +113,6 @@ public abstract class Transaction {
 		}
 	}
 
-	public static Class<?> getClassByTxType(TransactionType txType) {
-		try {
-			return Class.forName(String.join("", Transaction.class.getPackage().getName(), ".", txType.className, "Transaction"));
-		} catch (ClassNotFoundException e) {
-			return null;
-		}
-	}
-
 	// Validation results
 	public enum ValidationResult {
 		OK(1),
@@ -207,13 +221,13 @@ public abstract class Transaction {
 		TransactionType type = transactionData.getType();
 
 		try {
-			Class<?> transactionClass = Transaction.getClassByTxType(type);
-			if (transactionClass == null)
+			Constructor<?> constructor = type.constructor;
+
+			if (constructor == null)
 				throw new IllegalStateException("Unsupported transaction type [" + type.value + "] during fetch from repository");
 
-			Constructor<?> constructor = transactionClass.getConstructor(Repository.class, TransactionData.class);
 			return (Transaction) constructor.newInstance(repository, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | InstantiationException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException | InstantiationException e) {
 			throw new IllegalStateException("Internal error with transaction type [" + type.value + "] during fetch from repository");
 		}
 	}

src/main/java/org/qora/transform/transaction/AtTransactionTransformer.java

@@ -14,7 +14,7 @@ import org.qora.utils.Serialization;
 import com.google.common.primitives.Ints;
 import com.google.common.primitives.Longs;
 
-public class ATTransactionTransformer extends TransactionTransformer {
+public class AtTransactionTransformer extends TransactionTransformer {
 
 	// Property lengths
 	private static final int SENDER_LENGTH = ADDRESS_LENGTH;

src/main/java/org/qora/transform/transaction/TransactionTransformer.java

@@ -35,6 +35,7 @@ public abstract class TransactionTransformer extends Transformer {
 	protected static final int FEE_LENGTH = BIG_DECIMAL_LENGTH;
 	protected static final int BASE_TYPELESS_LENGTH = TIMESTAMP_LENGTH + REFERENCE_LENGTH + FEE_LENGTH + SIGNATURE_LENGTH;
 
+	/** Description of one component of raw transaction layout */
 	public enum TransformationType {
 		TIMESTAMP("milliseconds (long)", TIMESTAMP_LENGTH),
 		SIGNATURE("transaction signature", SIGNATURE_LENGTH),
@@ -57,6 +58,7 @@ public abstract class TransactionTransformer extends Transformer {
 		}
 	}
 
+	/** Description of one component of raw transaction layout for API use */
 	@XmlAccessorType(XmlAccessType.NONE)
 	public static class Transformation {
 		@XmlElement
@@ -71,17 +73,22 @@ public abstract class TransactionTransformer extends Transformer {
 			this.transformation = format;
 		}
 
-		@XmlElement(name = "format")
+		@XmlElement(
+			name = "format"
+		)
 		public String getFormat() {
 			return this.transformation.description;
 		}
 
-		@XmlElement(name = "length")
+		@XmlElement(
+			name = "length"
+		)
 		public Integer getLength() {
 			return this.transformation.length;
 		}
 	}
 
+	/** Container for raw transaction layout */
 	public static class TransactionLayout {
 		private List<Transformation> layout = new ArrayList<>();
 
@@ -94,23 +101,87 @@ public abstract class TransactionTransformer extends Transformer {
 		}
 	}
 
-	private static Class<?> getClassByTxType(TransactionType txType) {
-		try {
-			return Class.forName(String.join("", TransactionTransformer.class.getPackage().getName(), ".", txType.className, "TransactionTransformer"));
-		} catch (ClassNotFoundException e) {
-			return null;
+	/** Container for cache of transformer subclass reflection info */
+	public static class TransformerSubclassInfo {
+		public Class<?> clazz;
+		public TransactionLayout transactionLayout;
+		public Method fromByteBufferMethod;
+		public Method getDataLengthMethod;
+		public Method toBytesMethod;
+		public Method toBytesForSigningImplMethod;
+		public Method toJSONMethod;
+	}
+
+	/** Cache of transformer subclass info, keyed by transaction type */
+	private static final TransformerSubclassInfo[] subclassInfos;
+	static {
+		subclassInfos = new TransformerSubclassInfo[TransactionType.values().length + 1];
+
+		for (TransactionType txType : TransactionType.values()) {
+			TransformerSubclassInfo subclassInfo = new TransformerSubclassInfo();
+
+			try {
+				subclassInfo.clazz = Class
+						.forName(String.join("", TransactionTransformer.class.getPackage().getName(), ".", txType.className, "TransactionTransformer"));
+			} catch (ClassNotFoundException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass not found for transaction type \"%s\"", txType.name()));
+				continue;
+			}
+
+			try {
+				Field layoutField = subclassInfo.clazz.getDeclaredField("layout");
+				subclassInfo.transactionLayout = ((TransactionLayout) layoutField.get(null));
+			} catch (IllegalAccessException | IllegalArgumentException | NoSuchFieldException | SecurityException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"layout\" field not found for transaction type \"%s\"", txType.name()));
+			}
+
+			try {
+				subclassInfo.fromByteBufferMethod = subclassInfo.clazz.getDeclaredMethod("fromByteBuffer", ByteBuffer.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"fromByteBuffer\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			try {
+				subclassInfo.getDataLengthMethod = subclassInfo.clazz.getDeclaredMethod("getDataLength", TransactionData.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"getDataLength\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			try {
+				subclassInfo.toBytesMethod = subclassInfo.clazz.getDeclaredMethod("toBytes", TransactionData.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"toBytes\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			try {
+				Class<?> transformerClass = subclassInfo.clazz;
+
+				// Check method is actually declared in transformer, otherwise we have to call superclass version
+				if (Arrays.asList(transformerClass.getDeclaredMethods()).stream().noneMatch(method -> method.getName().equals("toBytesForSigningImpl")))
+					transformerClass = transformerClass.getSuperclass();
+
+				subclassInfo.toBytesForSigningImplMethod = transformerClass.getDeclaredMethod("toBytesForSigningImpl", TransactionData.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"toBytesFromSigningImp\" method not found for transaction type \"%s\"",
+						txType.name()));
+			}
+
+			try {
+				subclassInfo.toJSONMethod = subclassInfo.clazz.getDeclaredMethod("toJSON", TransactionData.class);
+			} catch (IllegalArgumentException | SecurityException | NoSuchMethodException e) {
+				LOGGER.debug(String.format("TransactionTransformer subclass's \"toJSON\" method not found for transaction type \"%s\"", txType.name()));
+			}
+
+			subclassInfos[txType.value] = subclassInfo;
 		}
+
+		LOGGER.trace("Static init reflection completed");
 	}
 
 	public static List<Transformation> getLayoutByTxType(TransactionType txType) {
 		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(txType);
-			if (transformerClass == null)
-				return null;
-
-			Field layoutField = transformerClass.getDeclaredField("layout");
-			return ((TransactionLayout) layoutField.get(null)).getLayout();
-		} catch (IllegalAccessException | IllegalArgumentException | NoSuchFieldException | SecurityException e) {
+			return subclassInfos[txType.value].transactionLayout.getLayout();
+		} catch (ArrayIndexOutOfBoundsException | NullPointerException e) {
 			return null;
 		}
 	}
@@ -130,16 +201,15 @@ public abstract class TransactionTransformer extends Transformer {
 		if (type == null)
 			return null;
 
-		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(type);
-			if (transformerClass == null)
-				throw new TransformationException("Unsupported transaction type [" + type.value + "] during conversion from bytes");
+		Method method = subclassInfos[type.value].fromByteBufferMethod;
+		if (method == null)
+			throw new TransformationException("Unsupported transaction type [" + type.value + "] during conversion from bytes");
 
-			Method method = transformerClass.getDeclaredMethod("fromByteBuffer", ByteBuffer.class);
+		try {
 			return (TransactionData) method.invoke(null, byteBuffer);
 		} catch (BufferUnderflowException e) {
 			throw new TransformationException("Byte data too short for transaction type [" + type.value + "]");
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new TransformationException("Internal error with transaction type [" + type.value + "] during conversion from bytes");
 		}
 	}
@@ -148,13 +218,9 @@ public abstract class TransactionTransformer extends Transformer {
 		TransactionType type = transactionData.getType();
 
 		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(type);
-			if (transformerClass == null)
-				throw new TransformationException("Unsupported transaction type [" + type.value + "] when requesting byte length");
-
-			Method method = transformerClass.getDeclaredMethod("getDataLength", TransactionData.class);
+			Method method = subclassInfos[type.value].getDataLengthMethod;
 			return (int) method.invoke(null, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new TransformationException("Internal error with transaction type [" + type.value + "] when requesting byte length");
 		}
 	}
@@ -163,13 +229,9 @@ public abstract class TransactionTransformer extends Transformer {
 		TransactionType type = transactionData.getType();
 
 		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(type);
-			if (transformerClass == null)
-				throw new TransformationException("Unsupported transaction type [" + type.value + "] during conversion to bytes");
-
-			Method method = transformerClass.getDeclaredMethod("toBytes", TransactionData.class);
+			Method method = subclassInfos[type.value].toBytesMethod;
 			return (byte[]) method.invoke(null, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new TransformationException("Internal error with transaction type [" + type.value + "] during conversion to bytes");
 		}
 	}
@@ -187,17 +249,9 @@ public abstract class TransactionTransformer extends Transformer {
 		TransactionType type = transactionData.getType();
 
 		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(type);
-			if (transformerClass == null)
-				throw new TransformationException("Unsupported transaction type [" + type.value + "] during conversion to bytes for signing");
-
-			// Check method is actually declared in transformer, otherwise we have to call superclass version
-			if (Arrays.asList(transformerClass.getDeclaredMethods()).stream().noneMatch(method -> method.getName().equals("toBytesForSigningImpl")))
-				transformerClass = transformerClass.getSuperclass();
-
-			Method method = transformerClass.getDeclaredMethod("toBytesForSigningImpl", TransactionData.class);
+			Method method = subclassInfos[type.value].toBytesForSigningImplMethod;
 			return (byte[]) method.invoke(null, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new TransformationException("Internal error with transaction type [" + type.value + "] during conversion to bytes for signing");
 		}
 	}
@@ -226,13 +280,9 @@ public abstract class TransactionTransformer extends Transformer {
 		TransactionType type = transactionData.getType();
 
 		try {
-			Class<?> transformerClass = TransactionTransformer.getClassByTxType(type);
-			if (transformerClass == null)
-				throw new TransformationException("Unsupported transaction type [" + type.value + "] during conversion to JSON");
-
-			Method method = transformerClass.getDeclaredMethod("toJSON", TransactionData.class);
+			Method method = subclassInfos[type.value].toJSONMethod;
 			return (JSONObject) method.invoke(null, transactionData);
-		} catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+		} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
 			throw new TransformationException("Internal error with transaction type [" + type.value + "] during conversion to JSON");
 		}
 	}

src/main/java/org/qora/v1feeder.java

@@ -45,7 +45,7 @@ import org.qora.repository.RepositoryManager;
 import org.qora.repository.hsqldb.HSQLDBRepositoryFactory;
 import org.qora.transform.TransformationException;
 import org.qora.transform.block.BlockTransformer;
-import org.qora.transform.transaction.ATTransactionTransformer;
+import org.qora.transform.transaction.AtTransactionTransformer;
 import org.qora.utils.Base58;
 import org.qora.utils.Pair;
 import org.qora.utils.Triple;
@@ -498,7 +498,7 @@ public class v1feeder extends Thread {
 					TransactionData transactionData = new ATTransactionData(sender, recipient, amount, Asset.QORA, message, fee, timestamp, reference);
 					byte[] digest;
 					try {
-						digest = Crypto.digest(ATTransactionTransformer.toBytes(transactionData));
+						digest = Crypto.digest(AtTransactionTransformer.toBytes(transactionData));
 						byte[] signature = Bytes.concat(digest, digest);
 
 						transactionData = new ATTransactionData(sender, recipient, amount, Asset.QORA, message, fee, timestamp, reference, signature);