/**
* This method loads all of the fields in the mapTable argument via the dis stream, which is setup
* at the proper location.
*
* @param dis Input stream reading from the .dbf file.
* @param mapTable The dbf table being loaded.
* @throws IOException Thrown when the stream fails.
*/
private void loadFields(DataInputStream dis, DBFTable mapTable) throws IOException {
// NUMBER OF FIELDS (COLUMNS) IN THE TABLE
int numFields = (mapTable.getPositionOfFirstDataRecorded() - 32 - 2 + 1) / 32;
for (int i = 0; i < numFields; i++) {
// ANOTHER COLUMN
DBFField fieldToAdd = new DBFField();
mapTable.addField(fieldToAdd);
// FIELD NAME
String fieldName = "";
for (int j = 0; j < 11; j++) {
byte c = dis.readByte();
if (c != 0) fieldName += (char) c;
}
fieldToAdd.setName(fieldName);
// FIELD TYPE
byte fieldTypeAsByte = dis.readByte();
char fieldType = (char) fieldTypeAsByte;
if (fieldType == 'C') fieldToAdd.setType(DBFFieldType.C);
else fieldToAdd.setType(DBFFieldType.N);
// DISPLACEMENT OF FIELD IN RECORD (12-15)
int displacementOfFieldInRecord = readLittleEndianInt(dis);
fieldToAdd.setDisplacement(displacementOfFieldInRecord);
// LENGTH OF FIELD (16)
int lengthOfField = dis.readByte();
if (lengthOfField < 0) lengthOfField += 256;
fieldToAdd.setLength(lengthOfField);
// NUMBER OF DECIMAL PLACES (17)
byte numberOfDecimalPlaces = dis.readByte();
fieldToAdd.setNumberOfDecimalPlaces(numberOfDecimalPlaces);
// FIELD FLAGS (18)
byte fieldFlags = dis.readByte();
fieldToAdd.setFlags(fieldFlags);
// AUTOINCREMENT NEXT (19-22)
int next = readLittleEndianInt(dis);
fieldToAdd.setNext(next);
// AUTOINCREMENT STEP (23)
byte step = dis.readByte();
fieldToAdd.setStep(step);
// RESERVED (24-31) - WE WON'T USE THIS
long reservedFieldData = dis.readLong();
fieldToAdd.setReservedData(reservedFieldData);
}
}
/**
* This helper method saves just the .dbf file header portion of the mapTable argument using the
* dos stream.
*
* @param dos The stream writing to the .dbf file.
* @param mapTable The dbf table being saved.
* @throws IOException Thrown when the stream fails.
*/
private void saveHeader(DataOutputStream dos, DBFTable mapTable) throws IOException {
// DBF file type (0)
dos.writeByte(mapTable.getFileType());
// LAST UPDATE (1-3)
byte year = (byte) (mapTable.getLastModifiedDate().get(Calendar.YEAR) - 1900);
byte month = (byte) (mapTable.getLastModifiedDate().get(Calendar.MONTH) + 1);
byte day = (byte) (mapTable.getLastModifiedDate().get(Calendar.DATE));
dos.writeByte(year);
dos.writeByte(month);
dos.writeByte(day);
// NUMBER OF RECORDS IN FILE (4-7)
int numberOfRecordsInFile = Integer.reverseBytes(mapTable.getNumberOfRecords());
dos.writeInt(numberOfRecordsInFile);
// POSITION OF FIRST DATA RECORDED (8-9)
short positionOfFirstDataRecorded =
Short.reverseBytes(mapTable.getPositionOfFirstDataRecorded());
dos.writeShort(positionOfFirstDataRecorded);
// LENGTH OF ONE DATA RECORD, INCLUDING DELETE FLAG (10-11)
short dataRecordLength = Short.reverseBytes(mapTable.getDataRecordLength());
dos.writeShort(dataRecordLength);
// ZEROES (12-13)
short zeroes = Short.reverseBytes(mapTable.getZeroes());
dos.writeShort(zeroes);
// DBASE IV Transaction Flag (14)
dos.writeByte(mapTable.getDbaseTransactionFlag());
// DBASE IV Encryption Flag (15)
dos.writeByte(mapTable.getDbaseEncryptionFlag());
// Multiuser Processing 12 Bytes (16-27)
int[] mup = mapTable.getMup();
dos.writeInt(Integer.reverseBytes(mup[0]));
dos.writeInt(Integer.reverseBytes(mup[1]));
dos.writeInt(Integer.reverseBytes(mup[2]));
// TABLE FLAGS (28)
dos.writeByte(mapTable.getFlags());
// CODE PAGE MARK/LANGUAGE DRIVER ID (29)
dos.writeByte(mapTable.getCodePageMark());
// RESERVED, CONTAINS 0x00 (30-31)
dos.writeShort(Short.reverseBytes(mapTable.getReserved()));
}
/**
* This method saves all of the fields in the mapTable argument via the dos stream, which is setup
* at the proper location.
*
* @param dos Output stream writing to the .dbf file.
* @param mapTable The dbf table being saved.
* @throws IOException Thrown when the stream fails.
*/
private void saveFields(DataOutputStream dos, DBFTable mapTable) throws IOException {
// NUMBER OF FIELDS (COLUMNS) IN THE TABLE
int numFields = (mapTable.getPositionOfFirstDataRecorded() - 32 - 2 + 1) / 32;
for (int i = 0; i < numFields; i++) {
// HERE'S THE FIELD WE'RE SAVING
DBFField fieldToSave = mapTable.getField(i);
// FIELD NAME
String fieldName = fieldToSave.getName();
int j = 0;
for (; j < fieldName.length(); j++) {
byte c = (byte) fieldName.charAt(j);
dos.writeByte(c);
}
byte z = (byte) 0x00;
while (j < 11) {
dos.writeByte(z);
j++;
}
// FIELD TYPE
dos.writeByte((byte) (fieldToSave.getType().toString().charAt(0)));
// DISPLACEMENT OF FIELD IN RECORD (12-15)
dos.writeInt(Integer.reverseBytes(fieldToSave.getDisplacement()));
// LENGTH OF FIELD (16)
dos.writeByte((byte) fieldToSave.getLength());
// NUMBER OF DECIMAL PLACES (17)
dos.writeByte(fieldToSave.getNumberOfDecimalPlaces());
// FIELD FLAGS (18)
dos.writeByte(fieldToSave.getFlags());
// AUTOINCREMENT NEXT (19-22)
dos.writeInt(Integer.reverseBytes(fieldToSave.getNext()));
// AUTOINCREMENT STEP (23)
dos.writeByte(fieldToSave.getStep());
// RESERVED (24-31) - WE WON'T USE THIS
dos.writeLong(fieldToSave.getReservedData());
}
}
