Some serialization

Add Transaction.parse() support. Subclasses are called, switched by transaction type,
using ByteBuffer.

Correct RECIPIENT_LENGTH in Transaction.

Common [de]serialization tasks moved to methods in Serialization class.

src/qora/transaction/GenesisTransaction.java

@@ -3,6 +3,7 @@ package qora.transaction;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigDecimal;
+import java.nio.ByteBuffer;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -31,7 +32,7 @@ public class GenesisTransaction extends Transaction {
 	private BigDecimal amount;
 
 	// Property lengths
-	private static final int RECIPIENT_LENGTH = 32;
+	private static final int RECIPIENT_LENGTH = 25; // raw, not Base58-encoded
 	private static final int AMOUNT_LENGTH = 8;
 	// Note that Genesis transactions don't require reference, fee or signature:
 	private static final int TYPELESS_LENGTH = TIMESTAMP_LENGTH + RECIPIENT_LENGTH + AMOUNT_LENGTH;
@@ -110,9 +111,15 @@ public class GenesisTransaction extends Transaction {
 
 	// Converters
 
-	public static Transaction parse(byte[] data) throws Exception {
+	protected static Transaction parse(ByteBuffer byteBuffer) throws TransactionParseException {
-		// TODO
+		if (byteBuffer.remaining() < TYPELESS_LENGTH)
-		return null;
+			throw new TransactionParseException("Byte data too short for GenesisTransaction");
+
+		long timestamp = byteBuffer.getLong();
+		String recipient = Serialization.deserializeRecipient(byteBuffer);
+		BigDecimal amount = Serialization.deserializeBigDecimal(byteBuffer);
+
+		return new GenesisTransaction(recipient, amount, timestamp);
 	}
 
 	@SuppressWarnings("unchecked")

src/qora/transaction/PaymentTransaction.java

@@ -3,6 +3,7 @@ package qora.transaction;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigDecimal;
+import java.nio.ByteBuffer;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -30,7 +31,6 @@ public class PaymentTransaction extends Transaction {
 
 	// Property lengths
 	private static final int SENDER_LENGTH = 32;
-	private static final int RECIPIENT_LENGTH = 32;
 	private static final int AMOUNT_LENGTH = 8;
 	private static final int TYPELESS_LENGTH = BASE_TYPELESS_LENGTH + SENDER_LENGTH + RECIPIENT_LENGTH + AMOUNT_LENGTH;
 
@@ -118,9 +118,22 @@ public class PaymentTransaction extends Transaction {
 
 	// Converters
 
-	public static Transaction parse(byte[] data) throws Exception {
+	protected static Transaction parse(ByteBuffer byteBuffer) throws TransactionParseException {
 		// TODO
-		return null;
+		if (byteBuffer.remaining() < TYPELESS_LENGTH)
+			throw new TransactionParseException("Byte data too short for PaymentTransaction");
+
+		long timestamp = byteBuffer.getLong();
+		byte[] reference = new byte[REFERENCE_LENGTH];
+		byteBuffer.get(reference);
+		PublicKeyAccount sender = Serialization.deserializePublicKey(byteBuffer);
+		String recipient = Serialization.deserializeRecipient(byteBuffer);
+		BigDecimal amount = Serialization.deserializeBigDecimal(byteBuffer);
+		BigDecimal fee = Serialization.deserializeBigDecimal(byteBuffer);
+		byte[] signature = new byte[SIGNATURE_LENGTH];
+		byteBuffer.get(signature);
+
+		return new PaymentTransaction(sender, recipient, amount, fee, timestamp, reference, signature);
 	}
 
 	@SuppressWarnings("unchecked")

src/qora/transaction/Transaction.java

@@ -2,6 +2,7 @@ package qora.transaction;
 
 import java.math.BigDecimal;
 import java.math.MathContext;
+import java.nio.ByteBuffer;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -89,7 +90,8 @@ public abstract class Transaction {
 	protected static final int BASE_TYPELESS_LENGTH = TIMESTAMP_LENGTH + REFERENCE_LENGTH + FEE_LENGTH + SIGNATURE_LENGTH;
 
 	// Other length constants
-	protected static final int CREATOR_LENGTH = 32;
+	public static final int CREATOR_LENGTH = 32;
+	public static final int RECIPIENT_LENGTH = 25;
 
 	// Constructors
 
@@ -283,6 +285,31 @@ public abstract class Transaction {
 
 	// Converters
 
+	public static Transaction parse(byte[] data) throws TransactionParseException {
+		if (data == null)
+			return null;
+
+		if (data.length < TYPE_LENGTH)
+			throw new TransactionParseException("Byte data too short to determine transaction type");
+
+		ByteBuffer byteBuffer = ByteBuffer.wrap(data);
+
+		TransactionType type = TransactionType.valueOf(byteBuffer.getInt());
+		if (type == null)
+			return null;
+
+		switch (type) {
+			case GENESIS:
+				return GenesisTransaction.parse(byteBuffer);
+
+			case PAYMENT:
+				return PaymentTransaction.parse(byteBuffer);
+
+			default:
+				return null;
+		}
+	}
+
 	public abstract JSONObject toJSON() throws SQLException;
 
 	/**

src/qora/transaction/TransactionParseException.java

@@ -0,0 +1,10 @@
+package qora.transaction;
+
+@SuppressWarnings("serial")
+public class TransactionParseException extends Exception {
+
+	public TransactionParseException(String message) {
+		super(message);
+	}
+
+}

src/test/transactions.java

@@ -0,0 +1,64 @@
+package test;
+
+import static org.junit.Assert.*;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+import database.DB;
+import qora.block.Block;
+import qora.block.GenesisBlock;
+import qora.transaction.GenesisTransaction;
+import qora.transaction.Transaction;
+import qora.transaction.TransactionParseException;
+
+public class transactions extends common {
+
+	@Test
+	public void testGenesisSerialization() throws SQLException, TransactionParseException {
+		GenesisBlock block = GenesisBlock.getInstance();
+
+		GenesisTransaction transaction = (GenesisTransaction) block.getTransactions().get(1);
+		assertNotNull(transaction);
+		System.out.println(transaction.getTimestamp() + ": " + transaction.getRecipient().getAddress() + " received " + transaction.getAmount().toPlainString());
+
+		byte[] bytes = transaction.toBytes();
+
+		GenesisTransaction parsedTransaction = (GenesisTransaction) Transaction.parse(bytes);
+		System.out.println(parsedTransaction.getTimestamp() + ": " + parsedTransaction.getRecipient().getAddress() + " received " + parsedTransaction.getAmount().toPlainString());
+
+		assertTrue(Arrays.equals(transaction.getSignature(), parsedTransaction.getSignature()));
+	}
+	
+	public void testGenericSerialization(Transaction transaction) throws SQLException, TransactionParseException {
+		assertNotNull(transaction);
+
+		byte[] bytes = transaction.toBytes();
+		
+		Transaction parsedTransaction = Transaction.parse(bytes);
+		
+		assertTrue(Arrays.equals(transaction.getSignature(), parsedTransaction.getSignature()));
+	}
+	
+	@Test
+	public void testPaymentSerialization() throws SQLException, TransactionParseException {
+		try (final Connection connection = DB.getConnection()) {
+			// Block 949 has lots of varied transactions
+			// Blocks 390 & 754 have only payment transactions
+			Block block = Block.fromHeight(754);
+			assertNotNull("Block 754 is required for this test", block);
+			assertTrue(block.isSignatureValid());
+			
+			List<Transaction> transactions = block.getTransactions();
+			assertNotNull(transactions);
+
+			for (Transaction transaction : transactions)
+				testGenericSerialization(transaction);
+		}
+	}
+	
+}

src/utils/Serialization.java

@@ -1,6 +1,11 @@
 package utils;
 
 import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.nio.ByteBuffer;
+
+import qora.account.PublicKeyAccount;
+import qora.transaction.Transaction;
 
 public class Serialization {
 
@@ -17,4 +22,22 @@ public class Serialization {
 		return output;
 	}
 
+	public static BigDecimal deserializeBigDecimal(ByteBuffer byteBuffer) {
+		byte[] bytes = new byte[8];
+		byteBuffer.get(bytes);
+		return new BigDecimal(new BigInteger(bytes), 8);
+	}
+
+	public static String deserializeRecipient(ByteBuffer byteBuffer) {
+		byte[] bytes = new byte[Transaction.RECIPIENT_LENGTH];
+		byteBuffer.get(bytes);
+		return Base58.encode(bytes);
+	}
+
+	public static PublicKeyAccount deserializePublicKey(ByteBuffer byteBuffer) {
+		byte[] bytes = new byte[Transaction.CREATOR_LENGTH];
+		byteBuffer.get(bytes);
+		return new PublicKeyAccount(bytes);
+	}
+
 }