more refactoring

src/data/block/Block.java

@@ -4,7 +4,7 @@ import java.math.BigDecimal;
 
 import qora.account.PublicKeyAccount;
 
-public class Block implements IBlockData {
+public class Block implements BlockData {
 	private int version;
 	private byte[] reference;
 	private int transactionCount;

src/data/block/BlockData.java

@@ -2,7 +2,7 @@ package data.block;
 
 import java.math.BigDecimal;
 
-public interface IBlockData {
+public interface BlockData {
 	public int getVersion();
 	public byte[] getReference();
 	public int getTransactionCount();

src/data/repository/IRepository.java

@@ -1,9 +0,0 @@
-package data.repository;
-
-import data.block.IBlockData;
-
-public interface IRepository {
-	// XXX use NoDataFoundException?
-	IBlockData getBlockBySignature(byte[] signature) throws Exception;
-	IBlockData getBlockByHeight(int height) throws Exception;
-}

src/data/transaction/Transaction.java

@@ -11,6 +11,8 @@ import static java.util.stream.Collectors.toMap;
 public abstract class Transaction {
 
 	// Transaction types
+	// TODO Transaction types are semantic and should go into the business logic layer.
+	// No need to know the meaning of the integer value in data layer
 	public enum TransactionType {
 		GENESIS(1), PAYMENT(2), REGISTER_NAME(3), UPDATE_NAME(4), SELL_NAME(5), CANCEL_SELL_NAME(6), BUY_NAME(7), CREATE_POLL(8), VOTE_ON_POLL(9), ARBITRARY(
 				10), ISSUE_ASSET(11), TRANSFER_ASSET(12), CREATE_ASSET_ORDER(13), CANCEL_ASSET_ORDER(14), MULTIPAYMENT(15), DEPLOY_AT(16), MESSAGE(17);
@@ -29,7 +31,8 @@ public abstract class Transaction {
 	}
 
 	// Properties shared with all transaction types
-	protected TransactionType type;
+	protected TransactionType type;	
+	// TODO PublicKeyAccount is a separate data entity, so here should only be a key to reference it 
 	protected PublicKeyAccount creator;
 	protected long timestamp;
 	protected byte[] reference;

src/qora/block/BlockFactory.java

@@ -6,19 +6,19 @@ import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
 
-import data.block.IBlockData;
-import data.repository.HSQLDBRepository;
-import data.repository.IRepository;
+import data.block.BlockData;
 import database.DB;
 import database.NoDataFoundException;
 import qora.account.PublicKeyAccount;
 import qora.transaction.Transaction;
 import qora.transaction.TransactionFactory;
+import repository.BlockRepository;
+import repository.hsqldb.HSQLDBBlockRepository;
 
 public class BlockFactory {
 
 	// XXX repository should be pushed here from the root entry, no need to know the repository type
-	private static IRepository repository = new HSQLDBRepository();
+	private static BlockRepository repository = new HSQLDBBlockRepository();
 	
 	/**
 	 * Load Block from DB using block signature.
@@ -52,7 +52,7 @@ public class BlockFactory {
 			return GenesisBlock.getInstance();
 
 		try {
-			IBlockData data = repository.getBlockByHeight(height);
+			BlockData data = repository.fromHeight(height);
 	
 			// TODO fill this list from TransactionFactory
 			List<Transaction> transactions = new ArrayList<Transaction>();

src/repository/BlockRepository.java

@@ -0,0 +1,8 @@
+package repository;
+
+import data.block.BlockData;
+
+public interface BlockRepository {
+	BlockData fromSignature(byte[] signature) throws DataException;
+	BlockData fromHeight(int height) throws DataException;
+}

src/repository/DataException.java

@@ -0,0 +1,22 @@
+package repository;
+
+public class DataException extends Exception {
+
+	private static final long serialVersionUID = -3963965667288257605L;
+
+    public DataException() {}
+
+    public DataException(String message)
+    {
+       super(message);
+    }
+    
+    public DataException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public DataException(Throwable cause) {
+        super(cause);
+    }
+
+}

src/repository/Repository.java

@@ -3,9 +3,13 @@ package repository;
 public abstract class Repository {
 
 	protected TransactionRepository transactionRepository;
+	protected BlockRepository blockRepository;
 
 	public TransactionRepository getTransactionRepository() {
 		return this.transactionRepository;
 	}
 
+	public BlockRepository getBlockRepository() {
+		return this.blockRepository;
+	}
 }

src/repository/RepositoryManager.java

@@ -12,4 +12,8 @@ public abstract class RepositoryManager {
 		return repository.transactionRepository;
 	}
 
+	public static BlockRepository getBlockRepository() {
+		return repository.blockRepository;
+	}
+
 }

src/repository/hsqldb/HSQLDBBlockRepository.java

@@ -1,4 +1,4 @@
-package data.repository;
+package repository.hsqldb;
 
 import java.math.BigDecimal;
 import java.sql.PreparedStatement;
@@ -7,11 +7,13 @@ import java.sql.SQLException;
 import java.sql.Timestamp;
 
 import data.block.Block;
-import data.block.IBlockData;
+import data.block.BlockData;
 import database.DB;
 import qora.account.PublicKeyAccount;
+import repository.BlockRepository;
+import repository.DataException;
 
-public class HSQLDBRepository implements IRepository
+public class HSQLDBBlockRepository implements BlockRepository
 {
 	protected static final int TRANSACTIONS_SIGNATURE_LENGTH = 64;
 	protected static final int GENERATOR_SIGNATURE_LENGTH = 64;
@@ -20,19 +22,29 @@ public class HSQLDBRepository implements IRepository
 	private static final String BLOCK_DB_COLUMNS = "version, reference, transaction_count, total_fees, "
 			+ "transactions_signature, height, generation, generating_balance, generator, generator_signature, AT_data, AT_fees";
 
-	public IBlockData getBlockBySignature(byte[] signature) throws SQLException
+	public BlockData fromSignature(byte[] signature) throws DataException
 	{		
-		ResultSet rs = DB.checkedExecute("SELECT " + BLOCK_DB_COLUMNS + " FROM Blocks WHERE signature = ?", signature);
+		ResultSet rs;
+		try {
+			rs = DB.checkedExecute("SELECT " + BLOCK_DB_COLUMNS + " FROM Blocks WHERE signature = ?", signature);
+		} catch (SQLException e) {
+			throw new DataException("Error loading data from DB", e);
+		}
 		return getBlockFromResultSet(rs);
 	}
 
-	public IBlockData getBlockByHeight(int height) throws SQLException
+	public BlockData fromHeight(int height) throws DataException
 	{		
-		ResultSet rs = DB.checkedExecute("SELECT " + BLOCK_DB_COLUMNS + " FROM Blocks WHERE height = ?", height);
+		ResultSet rs;
+		try {
+			rs = DB.checkedExecute("SELECT " + BLOCK_DB_COLUMNS + " FROM Blocks WHERE height = ?", height);
+		} catch (SQLException e) {
+			throw new DataException("Error loading data from DB", e);
+		}
 		return getBlockFromResultSet(rs);
 	}
 
-	private IBlockData getBlockFromResultSet(ResultSet rs) throws SQLException {
+	private BlockData getBlockFromResultSet(ResultSet rs) throws DataException {
 		int version = rs.getInt(1);
 		byte[] reference = DB.getResultSetBytes(rs.getBinaryStream(2), REFERENCE_LENGTH);
 		int transactionCount = rs.getInt(3);

src/repository/hsqldb/HSQLDBGenesisTransactionRepository.java

@@ -10,7 +10,7 @@ import data.transaction.GenesisTransaction;
 import data.transaction.Transaction;
 import database.DB;
 
-public class HSQLDBGenesisTransaction extends HSQLDBTransaction {
+public class HSQLDBGenesisTransactionRepository extends HSQLDBTransactionRepository {
 
 	Transaction fromBase(byte[] signature, byte[] reference, PublicKeyAccount creator, long timestamp, BigDecimal fee) {
 		try {

src/repository/hsqldb/HSQLDBRepository.java

@@ -5,7 +5,7 @@ import repository.Repository;
 public class HSQLDBRepository extends Repository {
 
 	public HSQLDBRepository() {
-		this.transactionRepository = new HSQLDBTransaction();
+		this.transactionRepository = new HSQLDBTransactionRepository();
 	}
 
 }

src/repository/hsqldb/HSQLDBTransactionRepository.java

@@ -12,12 +12,12 @@ import database.DB;
 import qora.block.Block;
 import repository.TransactionRepository;
 
-public class HSQLDBTransaction implements TransactionRepository {
+public class HSQLDBTransactionRepository implements TransactionRepository {
 
-	private HSQLDBGenesisTransaction genesisTransactionRepository;
+	private HSQLDBGenesisTransactionRepository genesisTransactionRepository;
 
-	public HSQLDBTransaction() {
-		genesisTransactionRepository = new HSQLDBGenesisTransaction();
+	public HSQLDBTransactionRepository() {
+		genesisTransactionRepository = new HSQLDBGenesisTransactionRepository();
 	}
 
 	public Transaction fromSignature(byte[] signature) {