java.awt.datatransfer
Class DataFlavor

java.lang.Object
  |
  +--java.awt.datatransfer.DataFlavor

All Implemented Interfaces:

Cloneable, Externalizable, Serializable

public class DataFlavor

extends Object

implements Externalizable, Cloneable

Each instance represents the opaque concept of a data format as would appear on a clipboard, during drag and drop, or in a file system.

DataFlavor objects are constant and never change once instantiated.

See Also:

Serialized Form

Field Summary

static DataFlavor	javaFileListFlavor To transfer a list of files to/from Java (and the underlying platform) a DataFlavor of this type/subtype and representation class of java.util.List is used.
static String	javaJVMLocalObjectMimeType to transfer a reference to an arbitrary Java object reference that has no associated MIME Content-type, across a Transferable interface WITHIN THE SAME JVM, a DataFlavor with this type/subtype is used, with a representationClass equal to the type of the class/interface being passed across the Transferble.
static String	javaRemoteObjectMimeType In order to pass a live link to a Remote object via a Drag and Drop ACTION_LINK operation a Mime Content Type of application/x-java-remote-object should be used, where the representation class of the DataFlavor represents the type of the Remote interface to be transferred.
static String	javaSerializedObjectMimeType a MIME Content-Type of application/x-java-serialized-object represents a graph of Java object(s) that have been made persistent.
static DataFlavor	plainTextFlavor Deprecated. as of 1.3. Use DataFlavor.getReaderForText( Transferable) instead of Transferable. getTransferData(DataFlavor.plainTextFlavor).
static DataFlavor	stringFlavor The DataFlavor representing a Java Unicode String class, where:

Constructor Summary

DataFlavor()
Constructs a new DataFlavor.

DataFlavor(Class representationClass, String humanPresentableName)
Construct a DataFlavor that represents a Java class

DataFlavor(String mimeType)
Construct a DataFlavor from a Mime Type string.

DataFlavor(String mimeType, String humanPresentableName)
Construct a DataFlavor that represents a MimeType

DataFlavor(String mimeType, String humanPresentableName, ClassLoader classLoader)
Construct a DataFlavor that represents a MimeType

Method Summary

Object	clone() Creates and returns a copy of this object.
boolean	equals(DataFlavor that) Two DataFlavors are considered equal if and only if their MIME primary type and subtype and representation class are equal.
boolean	equals(Object o) If the object is an instance of DataFlavor, representationClass and MIME type will be compared.
boolean	equals(String s) Deprecated. As inconsistent with hashCode() contract, use isMimeTypeEqual(String) instead.
Class	getDefaultRepresentationClass()
String	getDefaultRepresentationClassAsString()
String	getHumanPresentableName() Returns the human presentable name for the data foramt that this DataFlavor represents.
String	getMimeType() Returns the MIME type string for this DataFlavor
String	getParameter(String paramName)
String	getPrimaryType()
Reader	getReaderForText(Transferable transferable) Gets a reader for an input stream, decoded for the expected charset (encoding).
Class	getRepresentationClass() Returns the Class which objects supporting this DataFlavor will return when this DataFlavor is requested.
String	getSubType()
static DataFlavor	getTextPlainUnicodeFlavor()
int	hashCode() Returns hash code for this DataFlavor.
boolean	isFlavorJavaFileListType()
boolean	isFlavorRemoteObjectType()
boolean	isFlavorSerializedObjectType()
boolean	isMimeTypeEqual(DataFlavor dataFlavor) Compare the mimeType of two DataFlavor objects no parameters are considered
boolean	isMimeTypeEqual(String mimeType) Returns whether the string representation of the MIME type passed in is equivalent to the MIME type of this DataFlavor.
boolean	isMimeTypeSerializedObject() does the DataFlavor represent a serialized object?
boolean	isRepresentationClassInputStream() does the DataFlavor represent a java.io.InputStream
boolean	isRepresentationClassRemote()
boolean	isRepresentationClassSerializable()
boolean	match(DataFlavor that) Two DataFlavors match if their primary types, subtypes, and representation classes are all equal.
protected String	normalizeMimeType(String mimeType) Deprecated.
protected String	normalizeMimeTypeParameter(String parameterName, String parameterValue) Deprecated.
void	readExternal(ObjectInput is) restore this DataFlavor from an Serialized state
static DataFlavor	selectBestTextFlavor(DataFlavor[] availableFlavors)
void	setHumanPresentableName(String humanPresentableName) Sets the human presentable name for the data format that this DataFlavor represents.
String	toString() String representation of this DataFlavor and its parameters.
protected static Class	tryToLoadClass(String className, ClassLoader fallback) tried to load a class from: the bootstrap loader, the system loader, the context loader (if one is present) and finally the loader specified
void	writeExternal(ObjectOutput os) Serialize this DataFlavor

Methods inherited from class java.lang.Object

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

Field Detail

stringFlavor

public static final DataFlavor stringFlavor

The DataFlavor representing a Java Unicode String class, where:

representationClass = java.lang.String
mimeType = "application/x-java-serialized-object"

plainTextFlavor

public static final DataFlavor plainTextFlavor

Deprecated. as of 1.3. Use DataFlavor.getReaderForText( Transferable) instead of Transferable. getTransferData(DataFlavor.plainTextFlavor).

The DataFlavor representing plain text with unicode encoding, where:

representationClass = InputStream
mimeType = "text/plain; charset=unicode"

This DataFlavor has been deprecated because (1) Its representation is an InputStream, an 8-bit based representation, while Unicode is a 16-bit character set; and (2) The charset "unicode" is not well-defined. "unicode" implies a particular platform's implementation of Unicode, not a cross-platform implementation.

javaSerializedObjectMimeType

public static final String javaSerializedObjectMimeType

a MIME Content-Type of application/x-java-serialized-object represents a graph of Java object(s) that have been made persistent. The representation class associated with this DataFlavor identifies the Java type of an object returned as a reference from an invocation java.awt.datatransfer.getTransferData().

javaFileListFlavor

public static final DataFlavor javaFileListFlavor

To transfer a list of files to/from Java (and the underlying platform) a DataFlavor of this type/subtype and representation class of java.util.List is used. Each element of the list is required/guaranteed to be of type java.io.File.

javaJVMLocalObjectMimeType

public static final String javaJVMLocalObjectMimeType

to transfer a reference to an arbitrary Java object reference that has no associated MIME Content-type, across a Transferable interface WITHIN THE SAME JVM, a DataFlavor with this type/subtype is used, with a representationClass equal to the type of the class/interface being passed across the Transferble. The object reference returned from Transferable.getTransferData() for a DataFlavor with this MIME Content-Type is required to be an instanceof the representation Class of the DataFlavor.

javaRemoteObjectMimeType

public static final String javaRemoteObjectMimeType

In order to pass a live link to a Remote object via a Drag and Drop ACTION_LINK operation a Mime Content Type of application/x-java-remote-object should be used, where the representation class of the DataFlavor represents the type of the Remote interface to be transferred.

Constructor Detail

DataFlavor

public DataFlavor()

Constructs a new DataFlavor. This constructor is provided only for the purpose of supporting the Externalizable interface. It is not intended for public (client) use.

Since:

1.2

DataFlavor

public DataFlavor(Class representationClass,
                  String humanPresentableName)

Construct a DataFlavor that represents a Java class

The returned DataFlavor will have the following characteristics

representationClass = representationClass
mimeType = application/x-java-serialized-object

Parameters:

representationClass - the class used to transfer data in this flavor

humanPresentableName - the human-readable string used to identify this flavor. If this parameter is null then the value of the the MIME Content Type is used.

DataFlavor

public DataFlavor(String mimeType,
                  String humanPresentableName)

Construct a DataFlavor that represents a MimeType

The returned DataFlavor will have the following characteristics:

If the mimeType is "application/x-java-serialized-object; class=<representation class>", the result is the same as calling new DataFlavor(Class:forName(<representation class>) as above

otherwise:

representationClass = InputStream
mimeType = mimeType

Parameters:

mimeType - the string used to identify the MIME type for this flavor. If the the mimeType does not specify a "class=" parameter, or if the class is not successfully loaded, then an IllegalArgumentException is thrown.

humanPresentableName - the human-readable string used to identify this flavor. If this parameter is null then the value of the the MIME Content Type is used.

DataFlavor

public DataFlavor(String mimeType,
                  String humanPresentableName,
                  ClassLoader classLoader)
           throws ClassNotFoundException

Construct a DataFlavor that represents a MimeType

The returned DataFlavor will have the following characteristics:

If the mimeType is "application/x-java-serialized-object; class=<representation class>", the result is the same as calling new DataFlavor(Class:forName(<representation class>) as above

otherwise:

representationClass = InputStream
mimeType = mimeType

Parameters:

mimeType - the string used to identify the MIME type for this flavor

humanPresentableName - the human-readible string used to identify this flavor

DataFlavor

public DataFlavor(String mimeType)
           throws ClassNotFoundException

Construct a DataFlavor from a Mime Type string. The string can specify a "class=" parameter to create a DataFlavor with the desired representation class. If the string does not contain "class=" parameter, java.io.InputStream is used as default.

Parameters:

mimeType - the string used to identify the MIME type for this flavor. If the class specified by "class=" parameter is not successfully loaded, then an IllegalArgumentException is thrown.

Method Detail

tryToLoadClass

protected static final Class tryToLoadClass(String className,
                                            ClassLoader fallback)
                                     throws ClassNotFoundException

tried to load a class from: the bootstrap loader, the system loader, the context loader (if one is present) and finally the loader specified

Parameters:

fallback - the fallback loader

Throws:

ClassNotFoundException -

toString

public String toString()

String representation of this DataFlavor and its parameters. The result String contains name of DataFlavor class, representation class and Mime type of this Flavor.

Overrides:

toString in class Object

Returns:

string representation of this DataFlavor

getTextPlainUnicodeFlavor

public static final DataFlavor getTextPlainUnicodeFlavor()

selectBestTextFlavor

public static final DataFlavor selectBestTextFlavor(DataFlavor[] availableFlavors)

Returns:

the best (highest fidelity) flavor in an encoding supported by the JDK, or null if none can be found.

getReaderForText

public Reader getReaderForText(Transferable transferable)
                        throws UnsupportedFlavorException,
                               IOException

Gets a reader for an input stream, decoded for the expected charset (encoding). This works only if the representation class of this flavor is java.io.InputStream (or a subclass). In case of representation class being Reader the result will be this class itself.

Returns:

a Reader to read the data

Throws:

IllegalArgumentException - if the representation class is not java.io.InputStream or java.lang.String

IllegalArgumentException - if the charset (character encoding) is not supported by the JDK.

IllegalArgumentException - if the transferable has null data.

NullPointerException - if the transferable argument is null.

UnsupportedEncodingException - if the encoding is not supported by this flavor.

UnsupportedFlavorException - if the transferable does not support this flavor.

IOException - if the data cannot be read because of an I/O error.

getMimeType

public String getMimeType()

Returns the MIME type string for this DataFlavor

getRepresentationClass

public Class getRepresentationClass()

Returns the Class which objects supporting this DataFlavor will return when this DataFlavor is requested.

getHumanPresentableName

public String getHumanPresentableName()

Returns the human presentable name for the data foramt that this DataFlavor represents. This name would be localized for different countries

getPrimaryType

public String getPrimaryType()

Returns:

the primary MIME type of this DataFlavor

getSubType

public String getSubType()

Returns:

the Sub MIME type of this DataFlavor

getParameter

public String getParameter(String paramName)

Returns:

the value of the name parameter

setHumanPresentableName

public void setHumanPresentableName(String humanPresentableName)

Sets the human presentable name for the data format that this DataFlavor represents. This name would be localized for different countries

equals

public boolean equals(Object o)

If the object is an instance of DataFlavor, representationClass and MIME type will be compared. This method does not use equals(String) method, so it does not return true for the objects of String type.

Overrides:

equals in class Object

Returns:

if the objects are equal

equals

public boolean equals(DataFlavor that)

Two DataFlavors are considered equal if and only if their MIME primary type and subtype and representation class are equal. Additionally, if the primary type is "text", the charset parameter must also be equal. If either DataFlavor is of primary type "text", but no charset is specified, the platform default charset is assumed for that DataFlavor.

Returns:

if the DataFlavors represent exactly the same type.

equals

public boolean equals(String s)

Deprecated. As inconsistent with hashCode() contract, use isMimeTypeEqual(String) instead.

Compare only the mimeType against the passed in String and representationClass is not considered in the comparison. If representationClass needs to be compared, then equals(new DataFlavor(s)) may be used.

Returns:

if the String (MimeType) is equal

hashCode

public int hashCode()

Returns hash code for this DataFlavor. For two equal DataFlavors, hash codes are equal. For the String that matches DataFlavor.equals(String), it is not guaranteed that DataFlavor's hash code is equal to the hash code of the String.

Overrides:

hashCode in class Object

Returns:

a hash code for this DataFlavor

match

public boolean match(DataFlavor that)

Two DataFlavors match if their primary types, subtypes, and representation classes are all equal. Additionally, if the primary type is "text", the charset parameter is also considered. If either DataFlavor is of primary type "text", but no charset is specified, the platform default charset is assumed for that DataFlavor.

isMimeTypeEqual

public boolean isMimeTypeEqual(String mimeType)

Returns whether the string representation of the MIME type passed in is equivalent to the MIME type of this DataFlavor. Parameters are not incuded in the comparison. The comparison may involve adding default attributes for some MIME types (such as adding charset=US-ASCII to text/plain MIME types that have no charset parameter specified).

Parameters:

mimeType - the string representation of the MIME type

Returns:

true if the string representation of the MIME type passed in is equivalent to the MIME type of this DataFlavor; false otherwise.

Throws:

NullPointerException - if mimeType is null

isMimeTypeEqual

public final boolean isMimeTypeEqual(DataFlavor dataFlavor)

Compare the mimeType of two DataFlavor objects no parameters are considered

Returns:

if the MimeTypes are equal

isMimeTypeSerializedObject

public boolean isMimeTypeSerializedObject()

does the DataFlavor represent a serialized object?

getDefaultRepresentationClass

public final Class getDefaultRepresentationClass()

getDefaultRepresentationClassAsString

public final String getDefaultRepresentationClassAsString()

isRepresentationClassInputStream

public boolean isRepresentationClassInputStream()

does the DataFlavor represent a java.io.InputStream

isRepresentationClassSerializable

public boolean isRepresentationClassSerializable()

Returns:

true if the representation class can be serialized

isRepresentationClassRemote

public boolean isRepresentationClassRemote()

Returns:

true if the representation class is Remote

isFlavorSerializedObjectType

public boolean isFlavorSerializedObjectType()

Returns:

if the DataFlavor specified represents a Serialized Object

isFlavorRemoteObjectType

public boolean isFlavorRemoteObjectType()

Returns:

if the DataFlavor specified represents a Remote Object

isFlavorJavaFileListType

public boolean isFlavorJavaFileListType()

Returns:

if flavor specified represents a List of File objects

writeExternal

public void writeExternal(ObjectOutput os)
                   throws IOException

Serialize this DataFlavor

Specified by:

writeExternal in interface Externalizable

Following copied from interface: java.io.Externalizable

Parameters:

out - the stream to write the object to

Throws:

IOException - Includes any I/O exceptions that may occur

readExternal

public void readExternal(ObjectInput is)
                  throws IOException,
                         ClassNotFoundException

restore this DataFlavor from an Serialized state

Specified by:

readExternal in interface Externalizable

Following copied from interface: java.io.Externalizable

Parameters:

in - the stream to read data from in order to restore the object

Throws:

IOException - if I/O errors occur

ClassNotFoundException - If the class for an object being restored cannot be found.

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from class: Object

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

will be true, and that the expression:

 x.clone().getClass() == x.getClass()

will be true, but these are not absolute requirements. While it is typically the case that:

 x.clone().equals(x)

will be true, this is not an absolute requirement. Copying an object will typically entail creating a new instance of its class, but it also may require copying of internal data structures as well. No constructors are called.

The method clone for class Object performs a specific cloning operation. First, if the class of this object does not implement the interface Cloneable, then a CloneNotSupportedException is thrown. Note that all arrays are considered to implement the interface Cloneable. Otherwise, this method creates a new instance of the class of this object and initializes all its fields with exactly the contents of the corresponding fields of this object, as if by assignment; the contents of the fields are not themselves cloned. Thus, this method performs a "shallow copy" of this object, not a "deep copy" operation.

The class Object does not itself implement the interface Cloneable, so calling the clone method on an object whose class is Object will result in throwing an exception at run time. The clone method is implemented by the class Object as a convenient, general utility for subclasses that implement the interface Cloneable, possibly also overriding the clone method, in which case the overriding definition can refer to this utility definition by the call:

 super.clone()

Overrides:

clone in class Object

Returns:

a clone of this DataFlavor

normalizeMimeTypeParameter

protected String normalizeMimeTypeParameter(String parameterName,
                                            String parameterValue)

Deprecated.

Called on DataFlavor for every MIME Type parameter to allow DataFlavor subclasses to handle special parameters like the text/plain charset parameters, whose values are case insensitive. (MIME type parameter values are supposed to be case sensitive.

This method is called for each parameter name/value pair and should return the normalized representation of the parameterValue This method is never invoked by this implementation from 1.1 onwards

normalizeMimeType

protected String normalizeMimeType(String mimeType)

Deprecated.

Called for each MIME type string to give DataFlavor subtypes the opportunity to change how the normalization of MIME types is accomplished. One possible use would be to add default parameter/value pairs in cases where none are present in the MIME type string passed in This method is never invoked by this implementation from 1.1 onwards