com.googlecode.paradox.data.AbstractParadoxData Maven / Gradle / Ivy
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A Paradox Java Driver (using JDBC 4)
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/*
* Copyright (c) 2009 Leonardo Alves da Costa
*
* This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any
* later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
* License for more details. You should have received a copy of the GNU General Public License along with this
* program. If not, see the desired data type.
* @return the data file.
* @throws SQLException in case of reading errors.
*/
protected static T loadHeader(final File file, final ConnectionInfo connectionInfo)
throws SQLException {
final ByteBuffer buffer = ByteBuffer.allocate(Constants.MAX_BUFFER_SIZE);
buffer.order(ByteOrder.LITTLE_ENDIAN);
try (FileInputStream fs = new FileInputStream(file); FileChannel channel = fs.getChannel()) {
channel.read(buffer);
((Buffer) buffer).flip();
int recordSize = buffer.getShort() & 0xFFFF;
int headerSize = buffer.getShort() & 0xFFFF;
byte type = buffer.get();
@SuppressWarnings("unchecked")
T data = (T) newInstance(file, type, connectionInfo);
data.setRecordSize(recordSize);
data.setHeaderSize(headerSize);
data.setType(type);
data.setBlockSize(buffer.get());
data.setRowCount(buffer.getInt());
data.setUsedBlocks(buffer.getShort());
data.setTotalBlocks(buffer.getShort());
data.setFirstBlock(buffer.getShort());
data.setLastBlock(buffer.getShort());
buffer.position(0x21);
data.setFieldCount(buffer.getShort());
data.setPrimaryFieldCount(buffer.getShort());
// Check for encrypted file.
buffer.position(0x25);
int value = buffer.getInt();
data.setSortOrder(buffer.get());
buffer.position(0x2D);
data.setHeaderChangeCount(buffer.get());
data.setBlockChangeCount(buffer.get());
buffer.position(0x38);
data.setWriteProtected(buffer.get() != 0);
data.setVersionId(buffer.get());
// Paradox version 4.x and up.
if (value == 0xFF00_FF00 && data.getVersionId() > Constants.PARADOX_VERSION_4) {
buffer.position(0x5c);
value = buffer.getInt();
}
data.setEncryptedData(value);
buffer.position(0x49);
data.setAutoIncrementValue(buffer.getInt());
data.setFirstFreeBlock(buffer.getShort());
buffer.position(0x55);
data.setReferentialIntegrity(buffer.get());
// Only for DB files and Xnn files.
if (data instanceof ParadoxTable || data instanceof ParadoxIndex) {
parseVersionID(buffer, data, connectionInfo);
}
final ParadoxField[] fields = parseTableFields(data, buffer);
// Only for DB files and Xnn files.
if (data instanceof ParadoxTable || data instanceof ParadoxIndex) {
fixPositionByVersion(data, buffer, fields.length);
parseFieldsName(data, buffer, fields);
parseTableFieldsOrder(data, buffer);
}
if (data instanceof ParadoxIndex) {
parseSortID(buffer, data);
parseIndexName(buffer, data);
}
return data;
} catch (final BufferUnderflowException | IOException e) {
throw new ParadoxDataException(DataError.ERROR_LOADING_DATA, e);
}
}
/**
* Fix the buffer position based on file version ID.
*
* @param dataFile the Paradox data file.
* @param buffer the buffer to fix.
* @param fieldsSize the field list.
*/
private static void fixPositionByVersion(final ParadoxDataFile dataFile, final ByteBuffer buffer,
final int fieldsSize) {
// DB and Xnn files.
if (dataFile.getVersionId() > Constants.PARADOX_VERSION_4) {
if (dataFile.getVersionId() == 0xC) {
buffer.position(0x78 + 261 + 4 + (6 * fieldsSize));
} else {
buffer.position(0x78 + 83 + (6 * fieldsSize));
}
} else {
buffer.position(0x58 + 83 + (6 * fieldsSize));
}
}
/**
* Read fields attributes.
*
* @param dataFile the Paradox data file.
* @param buffer the buffer to read of.
* @return the Paradox field list.
*/
private static ParadoxField[] parseTableFields(final ParadoxDataFile dataFile, final ByteBuffer buffer) {
final ParadoxField[] fields = new ParadoxField[dataFile.getFieldCount()];
for (int loop = 0; loop < dataFile.getFieldCount(); loop++) {
final ParadoxField field = new ParadoxField(ParadoxType.valueOfVendor(buffer.get()), loop + 1);
field.setSize(buffer.get() & 0xFF);
if (dataFile instanceof Table) {
field.setTable((Table) dataFile);
}
fields[loop] = field;
}
return fields;
}
/**
* Parse the Paradox fields name.
*
* @param dataFile the Paradox data file.
* @param buffer the buffer to read of.
* @param fields the field list.
*/
private static void parseFieldsName(final ParadoxDataFile dataFile, final ByteBuffer buffer, final ParadoxField[] fields) {
final ByteBuffer name = ByteBuffer.allocate(261);
for (int loop = 0; loop < dataFile.getFieldCount(); loop++) {
name.clear();
byte c;
while ((c = buffer.get()) != 0) {
name.put(c);
}
name.flip();
fields[loop].setName(CharsetUtil.translate(dataFile, name));
}
dataFile.setFields(fields);
}
/**
* Parse the fields order.
*
* @param dataFile the Paradox data file.
* @param buffer the buffer to read of.
*/
private static void parseTableFieldsOrder(final ParadoxDataFile dataFile, final ByteBuffer buffer) {
final short[] fieldsOrder = new short[dataFile.getFieldCount()];
for (int loop = 0; loop < dataFile.getFieldCount(); loop++) {
fieldsOrder[loop] = buffer.getShort();
}
dataFile.setFieldsOrder(fieldsOrder);
}
/**
* Parse the sort order ID.
*
* @param buffer the buffer to parse.
* @param index the paradox index.
*/
private static void parseSortID(final ByteBuffer buffer, final ParadoxDataFile index) {
final ByteBuffer sortOrderID = ByteBuffer.allocate(26);
while (true) {
final byte c = buffer.get();
if (c == 0) {
break;
}
sortOrderID.put(c);
}
sortOrderID.flip();
index.setSortOrderID(CharsetUtil.translate(index, sortOrderID));
}
/**
* Parse the data file name.
*
* @param buffer the buffer to parse.
* @param index the paradox index.
*/
private static void parseIndexName(final ByteBuffer buffer, final ParadoxDataFile index) {
final ByteBuffer name = ByteBuffer.allocate(26);
while (true) {
final byte c = buffer.get();
if (c == 0) {
break;
}
name.put(c);
}
name.flip();
final String tempName = CharsetUtil.translate(index, name);
if (!tempName.isEmpty()) {
index.setName(tempName);
}
}
}