Class PalmDB

java.lang.Object
  |
  +--PalmDB

public class PalmDB

extends java.lang.Object

Converts between the Palm OS on-disk PRC format (used for applications and some data files) and a simple Java in-memory representation. With a slight effort, this could be extended to write and read PDB (the more common data format) as well.

The header fields are stored as publicly-accessible fields, along with a list of the records, each of which is stored as a PalmDB.PRCRecord. All the internals are visible, so be careful; this is quick and dirty, but it ain't rocket science anyway. Note especially that the records in a parsed file all initially share the same buffer of data. When modifying, replace it with a new buffer rather than overwriting other records' data!

Note: appInfo records and sortInfo records are ignored (with a warning) if present, and cannot be generated.

Used from the command line, reads a PRC file and dumps its entire contents to the console. This is equivalent to:

 	PalmDB db = load(new File(args[0]));
	System.out.println(db);
 

See http://www.palmos.com/ for more information on the file format.

TODO:
- Convert dates to and from a java date format (Calendar?)
- read and write appInfo and sortInfo records
- implement/test PDB support

Nested Class Summary

static class

PalmDB.Resource Note: when parsing, each record has a pointer into the same block of data, so either treat it as read-only (in terms of length, at least), or replace it with your own byte array to modify it.

Field Summary

int	attributes Somewhat mysterious bits.
int	creationDate Seconds since 1/1/1904.
java.lang.String	creator A four-character String containing a unique, registered database creator code.
int	lastBackupDate Seconds since 1/1/1904.
int	modificationDate Seconds since 1/1/1904.
int	modificationNumber Related to syncing, perhaps?
java.lang.String	name The name given to the file when it is written.
java.util.LinkedList	records Contains the Resources that contain the database's contents.
java.lang.String	type A four-character String containing a unique, registered database type.
int	uniqueIDSeed Not used for PRC.
int	version A version field (encoding is application-specific?)

Constructor Summary

PalmDB()

Method Summary

static PalmDB	load(java.io.File file) Reads a PRC file from the filesystem and parses its contents.
static void	main(java.lang.String[] args) Loads the PRC file named by the first argument and dumps its contents.
static PalmDB	parse(byte[] data) Breaks the elements of a PRC file into header and records for further processing.
void	save(java.io.File file) Write the contents of this PRCFile to the filesystem.
java.lang.String	toString()
byte[]	write() Captures the output of write(OutputStream) in a byte array, mostly for symmetry with the parsing side, and to simplify debugging.
void	write(java.io.OutputStream os) Writes the contents of this PRCFile to the given stream.

Methods inherited from class java.lang.Object

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

Field Detail

name

public java.lang.String name

The name given to the file when it is written.

attributes

public int attributes

Somewhat mysterious bits. Apparently, 0x01 is the 'isPRC' bit.

version

public int version

A version field (encoding is application-specific?)

creationDate

public int creationDate

Seconds since 1/1/1904. TODO: parse to/from Java Date or Calendar

modificationDate

public int modificationDate

Seconds since 1/1/1904. TODO: parse to/from Java Date or Calendar

lastBackupDate

public int lastBackupDate

Seconds since 1/1/1904. TODO: parse to/from Java Date or Calendar

modificationNumber

public int modificationNumber

Related to syncing, perhaps?

type

public java.lang.String type

A four-character String containing a unique, registered database type.

creator

public java.lang.String creator

A four-character String containing a unique, registered database creator code.

uniqueIDSeed

public int uniqueIDSeed

Not used for PRC. Set to 0.

records

public java.util.LinkedList records

Contains the Resources that contain the database's contents.

Constructor Detail

PalmDB

public PalmDB()

Method Detail

main

public static void main(java.lang.String[] args)

Loads the PRC file named by the first argument and dumps its contents.

load

public static PalmDB load(java.io.File file)
                   throws java.io.IOException

Reads a PRC file from the filesystem and parses its contents.

java.io.IOException

parse

public static PalmDB parse(byte[] data)

Breaks the elements of a PRC file into header and records for further processing.

Parameters:

data - The unparsed contents of a PRC file.

write

public void write(java.io.OutputStream os)
           throws java.io.IOException

Writes the contents of this PRCFile to the given stream.

java.io.IOException

write

public byte[] write()

Captures the output of write(OutputStream) in a byte array, mostly for symmetry with the parsing side, and to simplify debugging.

save

public void save(java.io.File file)
          throws java.io.IOException

Write the contents of this PRCFile to the filesystem.

java.io.IOException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object