home | O'Reilly's CD bookshelfs | FreeBSD | Linux | Cisco | Cisco Exam  

Java in a Nutshell

Previous Chapter 19
The java.awt.datatransfer Package

19.3 java.awt.datatransfer.DataFlavor (JDK 1.1)

Objects of this type define a data type or format for the purposes of data transfer. A DataFlavor is characterized by two values. The first is a descriptive human-readable name, passed to a DataFlavor() constructor or set with setHumanPresentableName().

The second component of a DataFlavor specifies the type of data to be transferred in a more machine-readable way. The two DataFlavor() constructors allow two distinct ways to specify this data type. One way is by directly specifying the representation class of the data. This is a Class object that defines the Java type that the recipient of a data transfer is passed. The other way to specify the data type represented by a DataFlavor is to pass a string that specifies the MIME type of the data to be transferred.

When you construct a DataFlavor object by specifying the representation type of the data, the MIME type of the DataFlavor is automatically set to:

application/x-java-serialized-object class=classname

This indicates that the object is to be transferred using the data format of the Java object serialization protocol. When you pass a MIME type string to the DataFlavor() constructor, on the other hand, the representation class of the DataFlavor is automatically set to the Class object for java.io.InputStream. This means that the recipient of the data transfer is given an InputStream object from which it can read and parse data in the specified MIME format.

Because the same MIME type can be specified with a number of slightly different strings, the DataFlavor class converts the MIME type to a canonical form so that it can be uniquely identified and compared. Use isMimeTypeEqual() to compare the MIME type of a DataFlavor object with another MIME type, or with the MIME type of another DataFlavor.

Because textual data is so often transferred, the DataFlavor class defines constants for two commonly-used data flavors. stringFlavor represents text transferred as a String object, while plainTextFlavor represents text transferred through an InputStream, using the text/plain MIME type.

public class DataFlavor extends Object {
    // Public Constructors
            public DataFlavor(Class representationClass, String humanPresentableName);
            public DataFlavor(String mimeType, String humanPresentableName);
    // Class Variables
            public static DataFlavor plainTextFlavor;
            public static DataFlavor stringFlavor;
    // Public Instance Methods
            public boolean equals(DataFlavor dataFlavor);
            public String getHumanPresentableName();
            public String getMimeType();
            public Class getRepresentationClass();
            public boolean isMimeTypeEqual(String mimeType);
            public final boolean isMimeTypeEqual(DataFlavor dataFlavor);
            public void setHumanPresentableName(String humanPresentableName);
    // Protected Instance Methods
            protected String normalizeMimeType(String mimeType);
            protected String normalizeMimeTypeParameter(String parameterName, String parameterValue);

Passed To:

DataFlavor.equals(), DataFlavor.isMimeTypeEqual(), StringSelection.getTransferData(), StringSelection.isDataFlavorSupported(), Transferable.getTransferData(), Transferable.isDataFlavorSupported(), UnsupportedFlavorException()

Returned By:

StringSelection.getTransferDataFlavors(), Transferable.getTransferDataFlavors()

Type Of:

DataFlavor.plainTextFlavor, DataFlavor.stringFlavor

Previous Home Next
java.awt.datatransfer.ClipboardOwner (JDK 1.1) Book Index java.awt.datatransfer.StringSelection (JDK 1.1)

Java in a Nutshell Java Language Reference Java AWT Java Fundamental Classes Exploring Java