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/*
* Copyright (c) 1997, 2018 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 org.jvnet.staxex;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamException;
/**
* {@link XMLStreamReader} extended for reading binary data.
*
*
* Some producer of infoset (in particular, such as FastInfoset,
* XOP decoder), uses a native format that enables efficient
* treatment of binary data. For ordinary infoset consumer
* (that just uses {@link XMLStreamReader}, those binary data
* will just look like base64-encoded string, but this interface
* allows consumers of such infoset to access this raw binary data.
* Such infoset producer may choose to implement this additoinal
* interface, to expose this functionality.
*
*
* Consumers that are capable of using this interface can query
* {@link XMLStreamReader} if it supports this by simply downcasting
* it to this interface like this:
*
*
* XMLStreamReader reader = ...;
* if( reader instanceof XMLStreamReaderEx ) {
* // this reader supports binary data exchange
* ...
* } else {
* // noop
* ...
* }
*
*
*
* Also note that it is also allowed for the infoset producer
* to implement this interface in such a way that {@link #getPCDATA()}
* always delegate to {@link #getText()}, although it's not desirable.
*
*
* This interface is a private contract between such producers
* and consumers to allow them to exchange binary data without
* converting it to base64.
*
* @see XMLStreamWriterEx
* @author Kohsuke Kawaguchi
* @author Paul Sandoz
*/
public interface XMLStreamReaderEx extends XMLStreamReader {
///**
// * Works like {@link XMLStreamReader#getText()}
// * but returns text as {@link DataSource}.
// *
// *
// * This method can be invoked whenever {@link XMLStreamReader#getText()}
// * can be invoked. Invoking this method means the caller is assuming
// * that the text is (conceptually) base64-encoded binary data.
// *
// *
// * This abstraction is necessary to treat XOP as infoset encoding.
// * That is, you can either access the XOP-attached binary through
// * {@link XMLStreamReader#getText()} (in which case you'll see the
// * base64 encoded string), or you can access it as a binary data
// * directly by using this method.
// *
// *
// * Note that even if you are reading from non XOP-aware {@link XMLStreamReader},
// * this method must be still supported; if the reader is pointing
// * to a text, this method is responsible for decoding base64 and
// * producing a {@link DataHandler} with "application/octet-stream"
// * as the content type.
// *
// * @return
// * always non-null valid object.
// * Invocations of this method may return the same object as long
// * as the {@link XMLStreamReader#next()} method is not used,
// * but otherwise {@link DataSource} object returned from this method
// * is considered to be owned by the client, and therefore it shouldn't
// * be reused by the implementation of this method.
// *
// *
// * The returned {@link DataSource} is read-only, and the caller
// * must not invoke {@link DataSource#getOutputStream()}.
// *
// * @throws IllegalStateException
// * if the parser is not pointing at characters infoset item.
// * @throws XMLStreamException
// * if the parser points to text but text is not base64-encoded text,
// * or if some other parsing error occurs (such as if the {@code }
// * points to a non-existing attachment.)
// *
// *
// * It is also OK for this method to return successfully, only to fail
// * during an {@link InputStream} is read from {@link DataSource}.
// */
//DataSource getTextAsDataHandler() throws XMLStreamException;
///**
// * Works like {@link XMLStreamReader#getText()}
// * but returns text as {@link byte[]}.
// *
// *
// * The contract of this method is mostly the same as
// * {@link #getTextAsDataHandler()}, except that this
// * method returns the binary datas as an exact-size byte[].
// *
// *
// * This method is also not capable of reporting the content type
// * of this binary data, even if it is available to the parser.
// *
// * @see #getTextAsDataHandler()
// */
//byte[] getTextAsByteArray() throws XMLStreamException;
/**
* Works like {@link #getText()}
* but hides the actual data representation.
*
* @return
* The {@link CharSequence} that represents the
* character infoset items at the current position.
*
*
* The {@link CharSequence} is normally a {@link String},
* but can be any other {@link CharSequence} implementation.
* For binary data, however, use of {@link Base64Data} is
* recommended (so that the consumer interested in seeing it
* as binary data may take advantage of mor efficient
* data representation.)
*
*
* The object returned from this method belongs to the parser,
* and its content is guaranteed to be the same only until
* the {@link #next()} method is invoked.
*
* @throws IllegalStateException
* if the parser is not pointing at characters infoset item.
*
* TODO:
* fix the dependency to JAXB internal class.
*/
CharSequence getPCDATA() throws XMLStreamException;
/**
* {@inheritDoc}
*/
NamespaceContextEx getNamespaceContext();
/**
* Works like {@link #getElementText()} but trims the leading
* and trailing whitespace.
*
*
* The parser can often do this more efficiently than
* {@code getElementText().trim()}.
*
* @see #getElementText()
*/
String getElementTextTrim() throws XMLStreamException;
}