jakarta.activation.DataContentHandler Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package jakarta.activation;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import jakarta.activation.DataSource;
/**
* The DataContentHandler interface is implemented by objects that can
* be used to extend the capabilities of the DataHandler's implementation
* of the Transferable interface. Through DataContentHandlers
* the framework can be extended to convert streams in to objects, and
* to write objects to streams.
*
* Applications don't generally call the methods in DataContentHandlers
* directly. Instead, an application calls the equivalent methods in
* DataHandler. The DataHandler will attempt to find an appropriate
* DataContentHandler that corresponds to its MIME type using the
* current DataContentHandlerFactory. The DataHandler then calls
* through to the methods in the DataContentHandler.
*/
public interface DataContentHandler {
/**
* Returns an array of ActivationDataFlavor objects indicating the flavors
* the data can be provided in. The array should be ordered according to
* preference for providing the data (from most richly descriptive to
* least descriptive).
*
* @return The ActivationDataFlavors.
*/
public ActivationDataFlavor[] getTransferDataFlavors();
/**
* Returns an object which represents the data to be transferred.
* The class of the object returned is defined by the representation class
* of the flavor.
*
* @param df The ActivationDataFlavor representing the requested type.
* @param ds The DataSource representing the data to be converted.
* @return The constructed Object.
* @exception IOException if the handler doesn't
* support the requested flavor
* @exception IOException if the data can't be accessed
*/
public Object getTransferData(ActivationDataFlavor df, DataSource ds)
throws IOException;
/**
* Return an object representing the data in its most preferred form.
* Generally this will be the form described by the first
* ActivationDataFlavor returned by the
* getTransferDataFlavors method.
*
* @param ds The DataSource representing the data to be converted.
* @return The constructed Object.
* @exception IOException if the data can't be accessed
*/
public Object getContent(DataSource ds) throws IOException;
/**
* Convert the object to a byte stream of the specified MIME type
* and write it to the output stream.
*
* @param obj The object to be converted.
* @param mimeType The requested MIME type of the resulting byte stream.
* @param os The output stream into which to write the converted
* byte stream.
* @exception IOException errors writing to the stream
*/
public void writeTo(Object obj, String mimeType, OutputStream os)
throws IOException;
}