java.awt.datatransfer
Class SystemFlavorMap

java.lang.Object
  java.awt.datatransfer.SystemFlavorMap

All Implemented Interfaces:

FlavorMap, FlavorTable

public final class SystemFlavorMap

extends Object

implements FlavorMap, FlavorTable

The SystemFlavorMap is a configurable map between "natives" (Strings), which correspond to platform-specific data formats, and "flavors" (DataFlavors), which correspond to platform-independent MIME types. This mapping is used by the data transfer subsystem to transfer data between Java and native applications, and between Java applications in separate VMs.

In the Sun reference implementation, the default SystemFlavorMap is initialized by the file jre/lib/flavormap.properties and the contents of the URL referenced by the AWT property AWT.DnD.flavorMapFileURL. See flavormap.properties for details.

Since:

1.2

Field Summary

private Set	disabledMappingGenerationKeys Dynamic mapping generation used for text mappings should not be applied to the DataFlavors and String natives for which the mappings have been explicitly specified with setFlavorsForNative() or setNativesForFlavor().
private static String[]	ENCODED_TEXT_CLASSES The list of valid, encoded text flavor representation classes, in order from best to worst.
private static WeakHashMap	flavorMaps System singleton which maps a thread's ClassLoader to a SystemFlavorMap.
private Map	flavorToNative Maps DataFlavors (or base type Strings for text DataFlavors) to Lists of native Strings.
private Map	getFlavorsForNativeCache Caches the result getFlavorsForNative().
private Map	getNativesForFlavorCache Caches the result of getNativesForFlavor().
private static String	JavaMIME Constant prefix used to tag Java types converted to native platform type.
private static String	keyValueSeparators Copied from java.util.Properties.
private Map	nativeToFlavor Maps native Strings to Lists of DataFlavors (or base type Strings for text DataFlavors).
private static String	strictKeyValueSeparators
private static boolean	SYNTHESIZE_IF_NOT_FOUND This constant is passed to flavorToNativeLookup() to indicate that a a native should be synthesized, stored, and returned by encoding the DataFlavor's MIME type in case if the DataFlavor is not found in 'flavorToNative' map.
private static String	TEXT_PLAIN_BASE_TYPE A String representing text/plain MIME type.
private static String[]	UNICODE_TEXT_CLASSES The list of valid, decoded text flavor representation classes, in order from best to worst.
private static String	whiteSpaceChars

Constructor Summary

private

SystemFlavorMap() Constructs a SystemFlavorMap by reading flavormap.properties and AWT.DnD.flavorMapFileURL.

Method Summary

void	addFlavorForUnencodedNative(String nat, DataFlavor flav) Adds a mapping from a single String native to a single DataFlavor.
void	addUnencodedNativeForFlavor(DataFlavor flav, String nat) Adds a mapping from the specified DataFlavor (and all DataFlavors equal to the specified DataFlavor) to the specified String native.
private boolean	continueLine(String line) Copied from java.util.Properties.
static DataFlavor	decodeDataFlavor(String nat) Decodes a String native for use as a DataFlavor.
static String	decodeJavaMIMEType(String nat) Decodes a String native for use as a Java MIME type.
static String	encodeDataFlavor(DataFlavor flav) Encodes a DataFlavor for use as a String native.
static String	encodeJavaMIMEType(String mimeType) Encodes a MIME type for use as a String native.
private List	flavorToNativeLookup(DataFlavor flav, boolean synthesize) Semantically equivalent to 'flavorToNative.get(flav)'.
static FlavorMap	getDefaultFlavorMap() Returns the default FlavorMap for this thread's ClassLoader.
List	getFlavorsForNative(String nat) Returns a List of DataFlavors to which the specified String native can be translated by the data transfer subsystem.
Map	getFlavorsForNatives(String[] natives) Returns a Map of the specified String natives to their most preferred DataFlavor.
List	getNativesForFlavor(DataFlavor flav) Returns a List of String natives to which the specified DataFlavor can be translated by the data transfer subsystem.
Map	getNativesForFlavors(DataFlavor[] flavors) Returns a Map of the specified DataFlavors to their most preferred String native.
static boolean	isJavaMIMEType(String str) Returns whether the specified String is an encoded Java MIME type.
private String	loadConvert(String theString) Copied from java.util.Properties.
private List	nativeToFlavorLookup(String nat) Semantically equivalent to 'nativeToFlavor.get(nat)'.
private void	parseAndStoreReader(BufferedReader in) Copied code from java.util.Properties.
void	setFlavorsForNative(String nat, DataFlavor[] flavors) Discards the current mappings for the specified String native, and creates new mappings to the specified DataFlavors.
void	setNativesForFlavor(DataFlavor flav, String[] natives) Discards the current mappings for the specified DataFlavor and all DataFlavors equal to the specified DataFlavor, and creates new mappings to the specified String natives.
private void	store(Object hashed, Object listed, Map map) Stores the listed object under the specified hash key in map.

Methods inherited from class java.lang.Object

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

Field Detail

JavaMIME

private static String JavaMIME

Constant prefix used to tag Java types converted to native platform type.

flavorMaps

private static final WeakHashMap flavorMaps

System singleton which maps a thread's ClassLoader to a SystemFlavorMap.

keyValueSeparators

private static final String keyValueSeparators

Copied from java.util.Properties.

See Also:

Constant Field Values

strictKeyValueSeparators

private static final String strictKeyValueSeparators

See Also:

Constant Field Values

whiteSpaceChars

private static final String whiteSpaceChars

See Also:

Constant Field Values

UNICODE_TEXT_CLASSES

private static final String[] UNICODE_TEXT_CLASSES

The list of valid, decoded text flavor representation classes, in order from best to worst.

ENCODED_TEXT_CLASSES

private static final String[] ENCODED_TEXT_CLASSES

The list of valid, encoded text flavor representation classes, in order from best to worst.

TEXT_PLAIN_BASE_TYPE

private static final String TEXT_PLAIN_BASE_TYPE

A String representing text/plain MIME type.

See Also:

Constant Field Values

SYNTHESIZE_IF_NOT_FOUND

private static final boolean SYNTHESIZE_IF_NOT_FOUND

This constant is passed to flavorToNativeLookup() to indicate that a a native should be synthesized, stored, and returned by encoding the DataFlavor's MIME type in case if the DataFlavor is not found in 'flavorToNative' map.

See Also:

Constant Field Values

nativeToFlavor

private Map nativeToFlavor

Maps native Strings to Lists of DataFlavors (or base type Strings for text DataFlavors).

flavorToNative

private Map flavorToNative

Maps DataFlavors (or base type Strings for text DataFlavors) to Lists of native Strings.

getNativesForFlavorCache

private Map getNativesForFlavorCache

Caches the result of getNativesForFlavor(). Maps DataFlavors to SoftReferences which reference Lists of String natives.

getFlavorsForNativeCache

private Map getFlavorsForNativeCache

Caches the result getFlavorsForNative(). Maps String natives to SoftReferences which reference Lists of DataFlavors.

disabledMappingGenerationKeys

private Set disabledMappingGenerationKeys

Dynamic mapping generation used for text mappings should not be applied to the DataFlavors and String natives for which the mappings have been explicitly specified with setFlavorsForNative() or setNativesForFlavor(). This keeps all such keys.

Constructor Detail

SystemFlavorMap

private SystemFlavorMap()

Constructs a SystemFlavorMap by reading flavormap.properties and AWT.DnD.flavorMapFileURL.

Method Detail

getDefaultFlavorMap

public static FlavorMap getDefaultFlavorMap()

Returns the default FlavorMap for this thread's ClassLoader.

parseAndStoreReader

private void parseAndStoreReader(BufferedReader in)
                          throws IOException

Copied code from java.util.Properties. Parsing the data ourselves is the only way to handle duplicate keys and values.

Throws:

IOException

continueLine

private boolean continueLine(String line)

Copied from java.util.Properties.

loadConvert

private String loadConvert(String theString)

Copied from java.util.Properties.

store

private void store(Object hashed,
                   Object listed,
                   Map map)

Stores the listed object under the specified hash key in map. Unlike a standard map, the listed object will not replace any object already at the appropriate Map location, but rather will be appended to a List stored in that location.

nativeToFlavorLookup

private List nativeToFlavorLookup(String nat)

Semantically equivalent to 'nativeToFlavor.get(nat)'. This method handles the case where 'nat' is not found in 'nativeToFlavor'. In that case, a new DataFlavor is synthesized, stored, and returned, if and only if the specified native is encoded as a Java MIME type.

flavorToNativeLookup

private List flavorToNativeLookup(DataFlavor flav,
                                  boolean synthesize)

Semantically equivalent to 'flavorToNative.get(flav)'. This method handles the case where 'flav' is not found in 'flavorToNative' depending on the value of passes 'synthesize' parameter. If 'synthesize' is SYNTHESIZE_IF_NOT_FOUND a native is synthesized, stored, and returned by encoding the DataFlavor's MIME type. Otherwise an empty List is returned and 'flavorToNative' remains unaffected.

getNativesForFlavor

public List getNativesForFlavor(DataFlavor flav)

Returns a List of String natives to which the specified DataFlavor can be translated by the data transfer subsystem. The List will be sorted from best native to worst. That is, the first native will best reflect data in the specified flavor to the underlying native platform.

If the specified DataFlavor is previously unknown to the data transfer subsystem, then invoking this method will establish a mapping in both directions between the specified DataFlavor and an encoded version of its MIME type as its native.

Specified by:

getNativesForFlavor in interface FlavorTable

Parameters:

flav - the DataFlavor whose corresponding natives should be returned. If null is specified, all natives currently known to the data transfer subsystem are returned in a non-deterministic order.

Returns:

a java.util.List of java.lang.String objects which are platform-specific representations of platform- specific data formats

Since:

1.4

See Also:

encodeDataFlavor(java.awt.datatransfer.DataFlavor)

getFlavorsForNative

public List getFlavorsForNative(String nat)

Returns a List of DataFlavors to which the specified String native can be translated by the data transfer subsystem. The List will be sorted from best DataFlavor to worst. That is, the first DataFlavor will best reflect data in the specified native to a Java application.

If the specified native is previously unknown to the data transfer subsystem, and that native has been properly encoded, then invoking this method will establish a mapping in both directions between the specified native and a DataFlavor whose MIME type is a decoded version of the native.

Specified by:

getFlavorsForNative in interface FlavorTable

Parameters:

nat - the native whose corresponding DataFlavors should be returned. If null is specified, all DataFlavors currently known to the data transfer subsystem are returned in a non-deterministic order.

Returns:

a java.util.List of DataFlavor objects into which platform-specific data in the specified, platform-specific native can be translated

Since:

1.4

See Also:

encodeJavaMIMEType(java.lang.String)

getNativesForFlavors

public Map getNativesForFlavors(DataFlavor[] flavors)

Returns a Map of the specified DataFlavors to their most preferred String native. Each native value will be the same as the first native in the List returned by getNativesForFlavor for the specified flavor.

If a specified DataFlavor is previously unknown to the data transfer subsystem, then invoking this method will establish a mapping in both directions between the specified DataFlavor and an encoded version of its MIME type as its native.

Specified by:

getNativesForFlavors in interface FlavorMap

Parameters:

flavors - an array of DataFlavors which will be the key set of the returned Map. If null is specified, a mapping of all DataFlavors known to the data transfer subsystem to their most preferred String natives will be returned.

Returns:

a java.util.Map of DataFlavors to String natives

See Also:

getNativesForFlavor(java.awt.datatransfer.DataFlavor), encodeDataFlavor(java.awt.datatransfer.DataFlavor)

getFlavorsForNatives

public Map getFlavorsForNatives(String[] natives)

Returns a Map of the specified String natives to their most preferred DataFlavor. Each DataFlavor value will be the same as the first DataFlavor in the List returned by getFlavorsForNative for the specified native.

If a specified native is previously unknown to the data transfer subsystem, and that native has been properly encoded, then invoking this method will establish a mapping in both directions between the specified native and a DataFlavor whose MIME type is a decoded version of the native.

Specified by:

getFlavorsForNatives in interface FlavorMap

Parameters:

natives - an array of Strings which will be the key set of the returned Map. If null is specified, a mapping of all supported String natives to their most preferred DataFlavors will be returned.

Returns:

a java.util.Map of String natives to DataFlavors

See Also:

getFlavorsForNative(java.lang.String), encodeJavaMIMEType(java.lang.String)

addUnencodedNativeForFlavor

public void addUnencodedNativeForFlavor(DataFlavor flav,
                                        String nat)

Adds a mapping from the specified DataFlavor (and all DataFlavors equal to the specified DataFlavor) to the specified String native. Unlike getNativesForFlavor, the mapping will only be established in one direction, and the native will not be encoded. To establish a two-way mapping, call addFlavorForUnencodedNative as well. The new mapping will be of lower priority than any existing mapping. This method has no effect if a mapping from the specified or equal DataFlavor to the specified String native already exists.

Parameters:

flav - the DataFlavor key for the mapping

nat - the String native value for the mapping

Throws:

NullPointerException - if flav or nat is null

Since:

1.4

See Also:

addFlavorForUnencodedNative(java.lang.String, java.awt.datatransfer.DataFlavor)

setNativesForFlavor

public void setNativesForFlavor(DataFlavor flav,
                                String[] natives)

Discards the current mappings for the specified DataFlavor and all DataFlavors equal to the specified DataFlavor, and creates new mappings to the specified String natives. Unlike getNativesForFlavor, the mappings will only be established in one direction, and the natives will not be encoded. To establish two-way mappings, call setFlavorsForNative as well. The first native in the array will represent the highest priority mapping. Subsequent natives will represent mappings of decreasing priority.

If the array contains several elements that reference equal String natives, this method will establish new mappings for the first of those elements and ignore the rest of them.

It is recommended that client code not reset mappings established by the data transfer subsystem. This method should only be used for application-level mappings.

Parameters:

flav - the DataFlavor key for the mappings

natives - the String native values for the mappings

Throws:

NullPointerException - if flav or natives is null or if natives contains null elements

Since:

1.4

See Also:

setFlavorsForNative(java.lang.String, java.awt.datatransfer.DataFlavor[])

addFlavorForUnencodedNative

public void addFlavorForUnencodedNative(String nat,
                                        DataFlavor flav)

Adds a mapping from a single String native to a single DataFlavor. Unlike getFlavorsForNative, the mapping will only be established in one direction, and the native will not be encoded. To establish a two-way mapping, call addUnencodedNativeForFlavor as well. The new mapping will be of lower priority than any existing mapping. This method has no effect if a mapping from the specified String native to the specified or equal DataFlavor already exists.

Parameters:

nat - the String native key for the mapping

flav - the DataFlavor value for the mapping

Throws:

NullPointerException - if nat or flav is null

Since:

1.4

See Also:

addUnencodedNativeForFlavor(java.awt.datatransfer.DataFlavor, java.lang.String)

setFlavorsForNative

public void setFlavorsForNative(String nat,
                                DataFlavor[] flavors)

Discards the current mappings for the specified String native, and creates new mappings to the specified DataFlavors. Unlike getFlavorsForNative, the mappings will only be established in one direction, and the natives need not be encoded. To establish two-way mappings, call setNativesForFlavor as well. The first DataFlavor in the array will represent the highest priority mapping. Subsequent DataFlavors will represent mappings of decreasing priority.

If the array contains several elements that reference equal DataFlavors, this method will establish new mappings for the first of those elements and ignore the rest of them.

It is recommended that client code not reset mappings established by the data transfer subsystem. This method should only be used for application-level mappings.

Parameters:

nat - the String native key for the mappings

flavors - the DataFlavor values for the mappings

Throws:

NullPointerException - if nat or flavors is null or if flavors contains null elements

Since:

1.4

See Also:

setNativesForFlavor(java.awt.datatransfer.DataFlavor, java.lang.String[])

encodeJavaMIMEType

public static String encodeJavaMIMEType(String mimeType)

Encodes a MIME type for use as a String native. The format of an encoded representation of a MIME type is implementation-dependent. The only restrictions are:

• The encoded representation is null if and only if the MIME type String is null.
• The encoded representations for two non-null MIME type Strings are equal if and only if these Strings are equal according to String.equals(Object).

Sun's reference implementation of this method returns the specified MIME type String prefixed with JAVA_DATAFLAVOR:.

Parameters:

mimeType - the MIME type to encode

Returns:

the encoded String, or null if mimeType is null

encodeDataFlavor

public static String encodeDataFlavor(DataFlavor flav)

Encodes a DataFlavor for use as a String native. The format of an encoded DataFlavor is implementation-dependent. The only restrictions are:

• The encoded representation is null if and only if the specified DataFlavor is null or its MIME type String is null.
• The encoded representations for two non-null DataFlavors with non-null MIME type Strings are equal if and only if the MIME type Strings of these DataFlavors are equal according to String.equals(Object).

Sun's reference implementation of this method returns the MIME type String of the specified DataFlavor prefixed with JAVA_DATAFLAVOR:.

Parameters:

flav - the DataFlavor to encode

Returns:

the encoded String, or null if flav is null or has a null MIME type

isJavaMIMEType

public static boolean isJavaMIMEType(String str)

Returns whether the specified String is an encoded Java MIME type.

Parameters:

str - the String to test

Returns:

true if the String is encoded; false otherwise

decodeJavaMIMEType

public static String decodeJavaMIMEType(String nat)

Decodes a String native for use as a Java MIME type.

Parameters:

nat - the String to decode

Returns:

the decoded Java MIME type, or null if nat is not an encoded String native

decodeDataFlavor

public static DataFlavor decodeDataFlavor(String nat)
                                   throws ClassNotFoundException

Decodes a String native for use as a DataFlavor.

Parameters:

nat - the String to decode

Returns:

the decoded DataFlavor, or null if nat is not an encoded String native

Throws:

ClassNotFoundException