1/*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 * questions.
24 */
25
26package com.sun.xml.internal.org.jvnet.staxex;
27
28import javax.activation.DataHandler;
29import javax.xml.stream.XMLStreamException;
30import javax.xml.stream.XMLStreamWriter;
31import java.io.OutputStream;
32
33/**
34 * {@link XMLStreamWriter} extended to support XOP.
35 *
36 * <p>
37 * Some infoset serializer (such as XOP encoder, FastInfoset) uses a format
38 * that can represent binary data more efficiently than base64 encoding.
39 * Such infoset serializer may choose to implement this interface, to allow
40 * the caller to pass in binary data more efficiently without first converting
41 * it to binary data.
42 *
43 * <p>
44 * Callers capable of using this interface can see if the serializer supports
45 * it by simply downcasting {@link XMLStreamWriter} to {@link XMLStreamWriterEx}.
46 *
47 * <h2>TODO</h2>
48 * <ol>
49 * <li>
50 *   Add methods to write other primitive types, such as hex and integers
51 *   (and arrays of).
52 *   A textual implementation would write characters in accordance
53 *   to the canonical lexical definitions specified in W3C XML Schema: datatypes.
54 *   A MTOM implementation would write characters except for the case where octets
55 *   that would otherwise be base64 encoded when using the textual implementation.
56 *   A Fast Infoset implementation would encoded binary data the primitive types in
57 *   binary form.
58 * <li>
59 *   Consider renaming writeBinary to writeBytesAsBase64 to be consistent with
60 *   infoset abstraction.
61 * <li>
62 *   Add the ability to writeStart and writeEnd on attributes so that the same
63 *   methods for writing primitive types (and characters, which will require new methods)
64 *   can be used for writing attribute values as well as element content.
65 * </ol>
66 *
67 * @see XMLStreamReaderEx
68 * @author Kohsuke Kawaguchi
69 * @author Paul Sandoz
70 */
71public interface XMLStreamWriterEx extends XMLStreamWriter {
72
73    /**
74     * Write the binary data.
75     *
76     * <p>
77     * Conceptually (infoset-wise), this produces the base64-encoded binary data on the
78     * output. But this allows implementations like FastInfoset or XOP to do the smart
79     * thing.
80     *
81     * <p>
82     * The use of this method has some restriction to support XOP. Namely, this method
83     * must be invoked as a sole content of an element.
84     *
85     * <p>
86     * (data,start,len) triplet identifies the binary data to be written.
87     * After the method invocation, the callee owns the buffer.
88     *
89     * @param contentType
90     *      this mandatory parameter identifies the MIME type of the binary data.
91     *      If the MIME type isn't known by the caller, "application/octet-stream" can
92     *      be always used to indicate "I don't know." Never null.
93     */
94    void writeBinary(byte[] data, int start, int len, String contentType) throws XMLStreamException;
95
96    /**
97     * Writes the binary data.
98     *
99     * <p>
100     * This method works like the {@link #writeBinary(byte[], int, int, String)} method,
101     * except that it takes the binary data in the form of {@link DataHandler}, which
102     * contains a MIME type ({@link DataHandler#getContentType()} as well as the payload
103     * {@link DataHandler#getInputStream()}.
104     *
105     * @param data
106     *      always non-null. After this method call, the callee owns the data handler.
107     */
108    void writeBinary(DataHandler data) throws XMLStreamException;
109
110    /**
111     * Writes the binary data.
112     *
113     * <p>
114     * This version of the writeBinary method allows the caller to produce
115     * the binary data by writing it to {@link OutputStream}.
116     *
117     * <p>
118     * It is the caller's responsibility to write and close
119     * a stream before it invokes any other methods on {@link XMLStreamWriter}.
120     *
121     * TODO: experimental. appreciate feedback
122     * @param contentType
123     *      See the content-type parameter of
124     *      {@link #writeBinary(byte[], int, int, String)}. Must not be null.
125     *
126     * @return
127     *      always return a non-null {@link OutputStream}.
128     */
129    OutputStream writeBinary(String contentType) throws XMLStreamException;
130
131    /**
132     * Writes like {@link #writeCharacters(String)} but hides
133     * actual data format.
134     *
135     * @param data
136     *      The {@link CharSequence} that represents the
137     *      character infoset items to be written.
138     *
139     *      <p>
140     *      The {@link CharSequence} is normally a {@link String},
141     *      but can be any other {@link CharSequence} implementation.
142     *      For binary data, however, use of {@link Base64Data} is
143     *      recommended (so that the consumer interested in seeing it
144     *      as binary data may take advantage of mor efficient
145     *      data representation.)
146     *
147     */
148    void writePCDATA(CharSequence data) throws XMLStreamException;
149
150    /**
151     * {@inheritDoc}
152     */
153    NamespaceContextEx getNamespaceContext();
154}
155