com.itextpdf.kernel.xmp

Class XMPUtils

java.lang.Object

com.itextpdf.kernel.xmp.XMPUtils

public final class XMPUtils
extends Object

Utility methods for XMP. I included only those that are different from the Java default conversion utilities.

Since:

21.02.2006

Method Summary

Modifier and Type	Method and Description
static void	appendProperties(XMPMeta source, XMPMeta dest, boolean doAllProperties, boolean replaceOldValues) Alias without the new option deleteEmptyValues.
static void	appendProperties(XMPMeta source, XMPMeta dest, boolean doAllProperties, boolean replaceOldValues, boolean deleteEmptyValues) Append properties from one XMP object to another.
static String	catenateArrayItems(XMPMeta xmp, String schemaNS, String arrayName, String separator, String quotes, boolean allowCommas) Create a single edit string from an array of strings.
static String	convertFromBoolean(boolean value) Convert from boolean to string.
static String	convertFromDate(XMPDateTime value) Convert from XMPDateTime to string.
static String	convertFromDouble(double value) Convert from long to string.
static String	convertFromInteger(int value) Convert from int to string.
static String	convertFromLong(long value) Convert from long to string.
static boolean	convertToBoolean(String value) Convert from string to Boolean.
static XMPDateTime	convertToDate(String rawValue) Converts a string value to an XMPDateTime.
static double	convertToDouble(String rawValue) Converts a string value to a double.
static int	convertToInteger(String rawValue) Converts a string value to an int.
static long	convertToLong(String rawValue) Converts a string value to a long.
static byte[]	decodeBase64(String base64String) Decode from Base64 encoded string to raw data.
static String	encodeBase64(byte[] buffer) Convert from a byte array to a base64 encoded string.
static void	removeProperties(XMPMeta xmp, String schemaNS, String propName, boolean doAllProperties, boolean includeAliases) Remove multiple properties from an XMP object.
static void	separateArrayItems(XMPMeta xmp, String schemaNS, String arrayName, String catedStr, PropertyOptions arrayOptions, boolean preserveCommas) Separate a single edit string into an array of strings.

Methods inherited from class java.lang.Object

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

Method Detail

catenateArrayItems

public static String catenateArrayItems(XMPMeta xmp,
                                        String schemaNS,
                                        String arrayName,
                                        String separator,
                                        String quotes,
                                        boolean allowCommas)
                                 throws XMPException

Create a single edit string from an array of strings.

Parameters:

xmp - The XMP object containing the array to be catenated.

schemaNS - The schema namespace URI for the array. Must not be null or the empty string.

arrayName - The name of the array. May be a general path expression, must not be null or the empty string. Each item in the array must be a simple string value.

separator - The string to be used to separate the items in the catenated string. Defaults to "; ", ASCII semicolon and space (U+003B, U+0020).

quotes - The characters to be used as quotes around array items that contain a separator. Defaults to '"'

allowCommas - Option flag to control the catenation.

Returns:

Returns the string containing the catenated array items.

Throws:

XMPException - Forwards the Exceptions from the metadata processing

separateArrayItems

public static void separateArrayItems(XMPMeta xmp,
                                      String schemaNS,
                                      String arrayName,
                                      String catedStr,
                                      PropertyOptions arrayOptions,
                                      boolean preserveCommas)
                               throws XMPException

Separate a single edit string into an array of strings.

Parameters:

xmp - The XMP object containing the array to be updated.

schemaNS - The schema namespace URI for the array. Must not be null or the empty string.

arrayName - The name of the array. May be a general path expression, must not be null or the empty string. Each item in the array must be a simple string value.

catedStr - The string to be separated into the array items.

arrayOptions - Option flags to control the separation.

preserveCommas - Flag if commas shall be preserved

Throws:

XMPException - Forwards the Exceptions from the metadata processing

removeProperties

public static void removeProperties(XMPMeta xmp,
                                    String schemaNS,
                                    String propName,
                                    boolean doAllProperties,
                                    boolean includeAliases)
                             throws XMPException

Remove multiple properties from an XMP object. RemoveProperties was created to support the File Info dialog's Delete button, and has been been generalized somewhat from those specific needs. It operates in one of three main modes depending on the schemaNS and propName parameters:

• Non-empty schemaNS and propName - The named property is removed if it is an external property, or if the flag doAllProperties option is true. It does not matter whether the named property is an actual property or an alias.
• Non-empty schemaNS and empty propName - The all external properties in the named schema are removed. Internal properties are also removed if the flag doAllProperties option is set. In addition, aliases from the named schema will be removed if the flag includeAliases option is set.
• Empty schemaNS and empty propName - All external properties in all schema are removed. Internal properties are also removed if the flag doAllProperties option is passed. Aliases are implicitly handled because the associated actuals are internal if the alias is.

It is an error to pass an empty schemaNS and non-empty propName.

Parameters:

xmp - The XMP object containing the properties to be removed.

schemaNS - Optional schema namespace URI for the properties to be removed.

propName - Optional path expression for the property to be removed.

doAllProperties - Option flag to control the deletion: do internal properties in addition to external properties.

includeAliases - Option flag to control the deletion: Include aliases in the "named schema" case above. Note: Currently not supported.

Throws:

XMPException - Forwards the Exceptions from the metadata processing

appendProperties

public static void appendProperties(XMPMeta source,
                                    XMPMeta dest,
                                    boolean doAllProperties,
                                    boolean replaceOldValues)
                             throws XMPException

Alias without the new option deleteEmptyValues.

Parameters:

source - The source XMP object.

dest - The destination XMP object.

doAllProperties - Do internal properties in addition to external properties.

replaceOldValues - Replace the values of existing properties.

Throws:

XMPException - Forwards the Exceptions from the metadata processing

appendProperties

public static void appendProperties(XMPMeta source,
                                    XMPMeta dest,
                                    boolean doAllProperties,
                                    boolean replaceOldValues,
                                    boolean deleteEmptyValues)
                             throws XMPException

Append properties from one XMP object to another.

XMPUtils#appendProperties was created to support the File Info dialog's Append button, and has been been generalized somewhat from those specific needs. It appends information from one XMP object (source) to another (dest). The default operation is to append only external properties that do not already exist in the destination. The flag doAllProperties can be used to operate on all properties, external and internal. The flag replaceOldValues option can be used to replace the values of existing properties. The notion of external versus internal applies only to top level properties. The keep-or-replace-old notion applies within structs and arrays as described below.

• If replaceOldValues is true then the processing is restricted to the top level properties. The processed properties from the source (according to doAllProperties) are propagated to the destination, replacing any existing values.Properties in the destination that are not in the source are left alone.
• If replaceOldValues is not passed then the processing is more complicated. Top level properties are added to the destination if they do not already exist. If they do exist but differ in form (simple/struct/array) then the destination is left alone. If the forms match, simple properties are left unchanged while structs and arrays are merged.
• If deleteEmptyValues is passed then an empty value in the source XMP causes the corresponding destination XMP property to be deleted. The default is to treat empty values the same as non-empty values. An empty value is any of a simple empty string, an array with no items, or a struct with no fields. Qualifiers are ignored.

The detailed behavior is defined by the following pseudo-code:

    appendProperties ( sourceXMP, destXMP, doAllProperties, 
                        replaceOldValues, deleteEmptyValues ):
       for all source schema (top level namespaces):
          for all top level properties in sourceSchema:
             if doAllProperties or prop is external:
                appendSubtree ( sourceNode, destSchema, replaceOldValues, deleteEmptyValues )
 
    appendSubtree ( sourceNode, destParent, replaceOldValues, deleteEmptyValues ):
        if deleteEmptyValues and source value is empty:
            delete the corresponding child from destParent
        else if sourceNode not in destParent (by name):
           copy sourceNode's subtree to destParent
        else if replaceOld:
            delete subtree from destParent
            copy sourceNode's subtree to destParent
        else:
            // Already exists in dest and not replacing, merge structs and arrays
            if sourceNode and destNode forms differ:
                return, leave the destNode alone
            else if form is a struct:
                for each field in sourceNode:
                    AppendSubtree ( sourceNode.field, destNode, replaceOldValues )
            else if form is an alt-text array:
                copy new items by "xml:lang" value into the destination
            else if form is an array:
                copy new items by value into the destination, ignoring order and duplicates
 

Note: appendProperties can be expensive if replaceOldValues is not passed and the XMP contains large arrays. The array item checking described above is n-squared. Each source item is checked to see if it already exists in the destination, without regard to order or duplicates.

Simple items are compared by value and "xml:lang" qualifier, other qualifiers are ignored. Structs are recursively compared by field names, without regard to field order. Arrays are compared by recursively comparing all items.

Parameters:

source - The source XMP object.

dest - The destination XMP object.

doAllProperties - Do internal properties in addition to external properties.

replaceOldValues - Replace the values of existing properties.

deleteEmptyValues - Delete destination values if source property is empty.

Throws:

XMPException - Forwards the Exceptions from the metadata processing

convertToBoolean

public static boolean convertToBoolean(String value)
                                throws XMPException

Convert from string to Boolean.

Parameters:

value - The string representation of the Boolean.

Returns:

The appropriate boolean value for the string. The checked values for true and false are:

• XMPConst.TRUESTR and XMPConst.FALSESTR
• "t" and "f"
• "on" and "off"
• "yes" and "no"
• "value <> 0" and "value == 0"

Throws:

XMPException - If an empty string is passed.

convertFromBoolean

public static String convertFromBoolean(boolean value)

Convert from boolean to string.

Parameters:

value - a boolean value

Returns:

The XMP string representation of the boolean. The values used are given by the constnts XMPConst.TRUESTR and XMPConst.FALSESTR.

convertToInteger

public static int convertToInteger(String rawValue)
                            throws XMPException

Converts a string value to an int.

Parameters:

rawValue - the string value

Returns:

Returns an int.

Throws:

XMPException - If the rawValue is null or empty or the conversion fails.

convertFromInteger

public static String convertFromInteger(int value)

Convert from int to string.

Parameters:

value - an int value

Returns:

The string representation of the int.

convertToLong

public static long convertToLong(String rawValue)
                          throws XMPException

Converts a string value to a long.

Parameters:

rawValue - the string value

Returns:

Returns a long.

Throws:

XMPException - If the rawValue is null or empty or the conversion fails.

convertFromLong

public static String convertFromLong(long value)

Convert from long to string.

Parameters:

value - a long value

Returns:

The string representation of the long.

convertToDouble

public static double convertToDouble(String rawValue)
                              throws XMPException

Converts a string value to a double.

Parameters:

rawValue - the string value

Returns:

Returns a double.

Throws:

XMPException - If the rawValue is null or empty or the conversion fails.

convertFromDouble

public static String convertFromDouble(double value)

Convert from long to string.

Parameters:

value - a long value

Returns:

The string representation of the long.

convertToDate

public static XMPDateTime convertToDate(String rawValue)
                                 throws XMPException

Converts a string value to an XMPDateTime.

Parameters:

rawValue - the string value

Returns:

Returns an XMPDateTime-object.

Throws:

XMPException - If the rawValue is null or empty or the conversion fails.

convertFromDate

public static String convertFromDate(XMPDateTime value)

Convert from XMPDateTime to string.

Parameters:

value - an XMPDateTime

Returns:

The string representation of the long.

encodeBase64

public static String encodeBase64(byte[] buffer)

Convert from a byte array to a base64 encoded string.

Parameters:

buffer - the byte array to be converted

Returns:

Returns the base64 string.

decodeBase64

public static byte[] decodeBase64(String base64String)
                           throws XMPException

Decode from Base64 encoded string to raw data.

Parameters:

base64String - a base64 encoded string

Returns:

Returns a byte array containg the decoded string.

Throws:

XMPException - Thrown if the given string is not property base64 encoded