Package ch.so.agi.gretl.internal.shapefile.core

Class DbfWriter

java.lang.Object

ch.so.agi.gretl.internal.shapefile.core.DbfWriter

All Implemented Interfaces:

AutoCloseable

public final class DbfWriter
extends Object
implements AutoCloseable

Low-level writer for the .dbf attribute table (dBASE III).

The header is written first with a record count of 0 and patched at the end via patchRecordCount(int). Records are written one at a time; nothing is buffered.

Header geometry matches DbfReader: headerLength = 32 + 32 * numFields + 1 (including the 0x0D field terminator) and recordLength = 1 + sum(fieldLengths) (including the leading deleted flag).

The FileChannel is owned by ShapefileDatasetWriter; close() therefore does not close the channel.

Constructor Summary

Constructors

Constructor	Description
DbfWriter(FileChannel channel, List<DbfField> fields, Charset charset)

Method Summary

Modifier and Type	Method	Description
void	close()
int	headerLength()
void	patchRecordCount(int recordCount)	Patches the 4-byte little-endian record count at offset 4 in the header.
int	recordLength()
void	writeEndOfFile()	Writes the trailing 0x1A end-of-file marker at the current channel position.
void	writeHeader(int recordCount)	Writes the full DBF header at the start of the file with the given record count.
void	writeRecord(Object[] values)	Appends a single record at the current channel position.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DbfWriter

public DbfWriter(FileChannel channel,
 List<DbfField> fields,
 Charset charset)

Method Details

headerLength

public int headerLength()

recordLength

public int recordLength()

writeHeader

public void writeHeader(int recordCount)
                 throws IOException

Writes the full DBF header at the start of the file with the given record count.

Throws:

IOException

writeRecord

public void writeRecord(Object[] values)
                 throws IOException,
ShapefileMappingException

Appends a single record at the current channel position.

Throws:

IOException

ShapefileMappingException

writeEndOfFile

public void writeEndOfFile()
                    throws IOException

Writes the trailing 0x1A end-of-file marker at the current channel position.

Throws:

IOException

patchRecordCount

public void patchRecordCount(int recordCount)
                      throws IOException

Patches the 4-byte little-endian record count at offset 4 in the header.

Throws:

IOException

close

public void close()

Specified by:

close in interface AutoCloseable