loci.poi.hpsf

Class PropertySet

java.lang.Object

loci.poi.hpsf.PropertySet

Direct Known Subclasses:

MutablePropertySet

public class PropertySet
extends Object

Represents a property set in the Horrible Property Set Format (HPSF). These are usually metadata of a Microsoft Office document.

An application that wants to access these metadata should create an instance of this class or one of its subclasses by calling the factory method PropertySetFactory.create(java.io.InputStream) and then retrieve the information its needs by calling appropriate methods.

PropertySetFactory.create(java.io.InputStream) does its work by calling one of the constructors PropertySet(InputStream) or PropertySet(byte[]). If the constructor's argument is not in the Horrible Property Set Format, i.e. not a property set stream, or if any other error occurs, an appropriate exception is thrown.

A PropertySet has a list of Sections, and each Section has a Property array. Use getSections() to retrieve the Sections, then call Section.getProperties() for each Section to get hold of the Property arrays.

Since the vast majority of PropertySets contains only a single Section, the convenience method getProperties() returns the properties of a PropertySet's Section (throwing a NoSingleSectionException if the PropertySet contains more (or less) than exactly one Section).

Since:

2002-02-09

Version:

$Id: PropertySet.java 489730 2006-12-22 19:18:16Z bayard $

Author:

Rainer Klute <klute@rainer-klute.de>, Drew Varner (Drew.Varner hanginIn sc.edu)

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static byte[]	BYTE_ORDER_ASSERTION The "byteOrder" field must equal this value.
protected int	byteOrder Specifies this PropertySet's byte order.
protected ClassID	classID Specifies this PropertySet's "classID" field.
protected int	format Specifies this PropertySet's format.
(package private) static byte[]	FORMAT_ASSERTION The "format" field must equal this value.
static int	OS_MACINTOSH If the OS version field holds this value the property set stream was created on a Macintosh system.
static int	OS_WIN16 If the OS version field holds this value the property set stream was created on a 16-bit Windows system.
static int	OS_WIN32 If the OS version field holds this value the property set stream was created on a 32-bit Windows system.
protected int	osVersion Specifies the version of the operating system that created this PropertySet.
protected List	sections The sections in this PropertySet.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PropertySet() Creates an empty (uninitialized) PropertySet.
	PropertySet(byte[] stream) Creates a PropertySet instance from a byte array that represents a stream in the Horrible Property Set Format.
	PropertySet(byte[] stream, int offset, int length) Creates a PropertySet instance from a byte array that represents a stream in the Horrible Property Set Format.
	PropertySet(InputStream stream) Creates a PropertySet instance from an InputStream in the Horrible Property Set Format.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object o) Returns true if the PropertySet is equal to the specified parameter, else false.
int	getByteOrder() Returns the property set stream's low-level "byte order" field.
ClassID	getClassID() Returns the property set stream's low-level "class ID" field.
Section	getFirstSection() Gets the PropertySet's first section.
int	getFormat() Returns the property set stream's low-level "format" field.
int	getOSVersion() Returns the property set stream's low-level "OS version" field.
Property[]	getProperties() Convenience method returning the Property array contained in this property set.
protected Object	getProperty(int id) Convenience method returning the value of the property with the specified ID.
protected boolean	getPropertyBooleanValue(int id) Convenience method returning the value of a boolean property with the specified ID.
protected int	getPropertyIntValue(int id) Convenience method returning the value of the numeric property with the specified ID.
int	getSectionCount() Returns the number of Sections in the property set.
List	getSections() Returns the Sections in the property set.
Section	getSingleSection() If the PropertySet has only a single section this method returns it.
int	hashCode()
private void	init(byte[] src, int offset, int length) Initializes this PropertySet instance from a byte array.
boolean	isDocumentSummaryInformation() Checks whether this PropertySet is a Document Summary Information.
static boolean	isPropertySetStream(byte[] src, int offset, int length) Checks whether a byte array is in the Horrible Property Set Format.
static boolean	isPropertySetStream(InputStream stream) Checks whether an InputStream is in the Horrible Property Set Format.
boolean	isSummaryInformation() Checks whether this PropertySet represents a Summary Information.
String	toString()
boolean	wasNull() Checks whether the property which the last call to getPropertyIntValue(int) or getProperty(int) tried to access was available or not.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

BYTE_ORDER_ASSERTION

static final byte[] BYTE_ORDER_ASSERTION

The "byteOrder" field must equal this value.

byteOrder

protected int byteOrder

Specifies this PropertySet's byte order. See the HPFS documentation for details!

FORMAT_ASSERTION

static final byte[] FORMAT_ASSERTION

The "format" field must equal this value.

format

protected int format

Specifies this PropertySet's format. See the HPFS documentation for details!

osVersion

protected int osVersion

Specifies the version of the operating system that created this PropertySet. See the HPFS documentation for details!

OS_WIN16

public static final int OS_WIN16

If the OS version field holds this value the property set stream was created on a 16-bit Windows system.

See Also:

Constant Field Values

OS_MACINTOSH

public static final int OS_MACINTOSH

If the OS version field holds this value the property set stream was created on a Macintosh system.

See Also:

Constant Field Values

OS_WIN32

public static final int OS_WIN32

If the OS version field holds this value the property set stream was created on a 32-bit Windows system.

See Also:

Constant Field Values

classID

protected ClassID classID

Specifies this PropertySet's "classID" field. See the HPFS documentation for details!

sections

protected List sections

The sections in this PropertySet.

Constructor Detail

PropertySet

protected PropertySet()

Creates an empty (uninitialized) PropertySet.

Please note: For the time being this constructor is protected since it is used for internal purposes only, but expect it to become public once the property set's writing functionality is implemented.

PropertySet

public PropertySet(InputStream stream)
            throws NoPropertySetStreamException,
                   MarkUnsupportedException,
                   IOException,
                   UnsupportedEncodingException

Creates a PropertySet instance from an InputStream in the Horrible Property Set Format.

The constructor reads the first few bytes from the stream and determines whether it is really a property set stream. If it is, it parses the rest of the stream. If it is not, it resets the stream to its beginning in order to let other components mess around with the data and throws an exception.

Parameters:

stream - Holds the data making out the property set stream.

Throws:

MarkUnsupportedException - if the stream does not support the InputStream.markSupported() method.

IOException - if the InputStream cannot not be accessed as needed.

NoPropertySetStreamException - if the input stream does not contain a property set.

UnsupportedEncodingException - if a character encoding is not supported.

PropertySet

public PropertySet(byte[] stream,
           int offset,
           int length)
            throws NoPropertySetStreamException,
                   UnsupportedEncodingException

Creates a PropertySet instance from a byte array that represents a stream in the Horrible Property Set Format.

Parameters:

stream - The byte array holding the stream data.

offset - The offset in stream where the stream data begin. If the stream data begin with the first byte in the array, the offset is 0.

length - The length of the stream data.

Throws:

NoPropertySetStreamException - if the byte array is not a property set stream.

UnsupportedEncodingException - if the codepage is not supported.

PropertySet

public PropertySet(byte[] stream)
            throws NoPropertySetStreamException,
                   UnsupportedEncodingException

Creates a PropertySet instance from a byte array that represents a stream in the Horrible Property Set Format.

Parameters:

stream - The byte array holding the stream data. The complete byte array contents is the stream data.

Throws:

NoPropertySetStreamException - if the byte array is not a property set stream.

UnsupportedEncodingException - if the codepage is not supported.

Method Detail

getByteOrder

public int getByteOrder()

Returns the property set stream's low-level "byte order" field. It is always 0xFFFE .

Returns:

The property set stream's low-level "byte order" field.

getFormat

public int getFormat()

Returns the property set stream's low-level "format" field. It is always 0x0000 .

Returns:

The property set stream's low-level "format" field.

getOSVersion

public int getOSVersion()

Returns the property set stream's low-level "OS version" field.

Returns:

The property set stream's low-level "OS version" field.

getClassID

public ClassID getClassID()

Returns the property set stream's low-level "class ID" field.

Returns:

The property set stream's low-level "class ID" field.

getSectionCount

public int getSectionCount()

Returns the number of Sections in the property set.

Returns:

The number of Sections in the property set.

getSections

public List getSections()

Returns the Sections in the property set.

Returns:

The Sections in the property set.

isPropertySetStream

public static boolean isPropertySetStream(InputStream stream)
                                   throws MarkUnsupportedException,
                                          IOException

Checks whether an InputStream is in the Horrible Property Set Format.

Parameters:

stream - The InputStream to check. In order to perform the check, the method reads the first bytes from the stream. After reading, the stream is reset to the position it had before reading. The InputStream must support the InputStream.mark(int) method.

Returns:

true if the stream is a property set stream, else false.

Throws:

MarkUnsupportedException - if the InputStream does not support the InputStream.mark(int) method.

IOException - if an I/O error occurs

isPropertySetStream

public static boolean isPropertySetStream(byte[] src,
                          int offset,
                          int length)

Checks whether a byte array is in the Horrible Property Set Format.

Parameters:

src - The byte array to check.

offset - The offset in the byte array.

length - The significant number of bytes in the byte array. Only this number of bytes will be checked.

Returns:

true if the byte array is a property set stream, false if not.

init

private void init(byte[] src,
        int offset,
        int length)
           throws UnsupportedEncodingException

Initializes this PropertySet instance from a byte array. The method assumes that it has been checked already that the byte array indeed represents a property set stream. It does no more checks on its own.

Parameters:

src - Byte array containing the property set stream

offset - The property set stream starts at this offset from the beginning of src

length - Length of the property set stream.

Throws:

UnsupportedEncodingException - if HPSF does not (yet) support the property set's character encoding.

isSummaryInformation

public boolean isSummaryInformation()

Checks whether this PropertySet represents a Summary Information.

Returns:

true if this PropertySet represents a Summary Information, else false.

isDocumentSummaryInformation

public boolean isDocumentSummaryInformation()

Checks whether this PropertySet is a Document Summary Information.

Returns:

true if this PropertySet represents a Document Summary Information, else false.

getProperties

public Property[] getProperties()
                         throws NoSingleSectionException

Convenience method returning the Property array contained in this property set. It is a shortcut for getting the PropertySet's Sections list and then getting the Property array from the first Section.

Returns:

The properties of the only Section of this PropertySet.

Throws:

NoSingleSectionException - if the PropertySet has more or less than one Section.

getProperty

protected Object getProperty(int id)
                      throws NoSingleSectionException

Convenience method returning the value of the property with the specified ID. If the property is not available, null is returned and a subsequent call to wasNull() will return true .

Parameters:

id - The property ID

Returns:

The property value

Throws:

NoSingleSectionException - if the PropertySet has more or less than one Section.

getPropertyBooleanValue

protected boolean getPropertyBooleanValue(int id)
                                   throws NoSingleSectionException

Convenience method returning the value of a boolean property with the specified ID. If the property is not available, false is returned. A subsequent call to wasNull() will return true to let the caller distinguish that case from a real property value of false.

Parameters:

id - The property ID

Returns:

The property value

Throws:

NoSingleSectionException - if the PropertySet has more or less than one Section.

getPropertyIntValue

protected int getPropertyIntValue(int id)
                           throws NoSingleSectionException

Convenience method returning the value of the numeric property with the specified ID. If the property is not available, 0 is returned. A subsequent call to wasNull() will return true to let the caller distinguish that case from a real property value of 0.

Parameters:

id - The property ID

Returns:

The propertyIntValue value

Throws:

NoSingleSectionException - if the PropertySet has more or less than one Section.

wasNull

public boolean wasNull()
                throws NoSingleSectionException

Checks whether the property which the last call to getPropertyIntValue(int) or getProperty(int) tried to access was available or not. This information might be important for callers of getPropertyIntValue(int) since the latter returns 0 if the property does not exist. Using wasNull(), the caller can distiguish this case from a property's real value of 0.

Returns:

true if the last call to getPropertyIntValue(int) or getProperty(int) tried to access a property that was not available, else false.

Throws:

NoSingleSectionException - if the PropertySet has more than one Section.

getFirstSection

public Section getFirstSection()

Gets the PropertySet's first section.

Returns:

The PropertySet's first section.

getSingleSection

public Section getSingleSection()

If the PropertySet has only a single section this method returns it.

Returns:

The singleSection value

equals

public boolean equals(Object o)

Returns true if the PropertySet is equal to the specified parameter, else false.

Overrides:

equals in class Object

Parameters:

o - the object to compare this PropertySet with

Returns:

true if the objects are equal, false if not

hashCode

public int hashCode()

Overrides:

hashCode in class Object

See Also:

Object.hashCode()

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()