1 /* 2 * Copyright (c) 1997, 2015, 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 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.xml.internal.bind.v2.runtime.output; 27 28 import java.io.IOException; 29 30 import javax.xml.bind.JAXBContext; 31 import javax.xml.stream.XMLStreamException; 32 33 import com.sun.xml.internal.bind.v2.runtime.Name; 34 import com.sun.xml.internal.bind.v2.runtime.NameList; 35 import com.sun.xml.internal.bind.v2.runtime.XMLSerializer; 36 37 import org.xml.sax.SAXException; 38 39 /** 40 * Well-formed XML writer. 41 * 42 * <p> 43 * Implementations of this interface is used to connect {@link XMLSerializer} 44 * to the actual target. This allows {@link XMLSerializer} to be API agnostic. 45 * 46 * 47 * <h2>Notes</h2> 48 * <p> 49 * {@link JAXBContext} assigns indices to URIs and local names 50 * that are statically known by using {@link NameList}. 51 * {@link XmlOutput} implementation can use these indices to improve 52 * the performance. For example, those namespace URI indices can be 53 * turned into prefixes quickly. 54 * 55 * <p> 56 * {@link XmlOutput} still allows arbitrary namepsace URIs / local names 57 * to be written. 58 * 59 * <p> 60 * The {@link NamespaceContextImpl} object, which is shared between {@link XmlOutput} and 61 * {@link XMLSerializer}, keeps track of the in-scope namespace bindings. By the time 62 * the {@link #beginStartTag} method is called, all the namespace bindings for the new 63 * element is already declared. Similarly, after the {@link #endTag} method is called, 64 * in-scope bindings will be removed. This book keeping is all done outside {@link XmlOutput}. 65 * 66 * <p> 67 * {@link XmlOutput} and {@link XMLSerializer} uses indices to 68 * reference prefixes/URIs to be written. {@link NamespaceContextImpl} can 69 * convert prefix indices to URIs and the string representations of prefixes. 70 * Binding from indices to URIs and prefixes do not change while indices 71 * are "in scope", so {@link XmlOutput} is again expected to take advantage of 72 * this to improve the perofmrnace. 73 * 74 * <p> 75 * prefix index 0 is reserved for "xml", and this binding is assumed to be always there. 76 * {@link NamespaceContextImpl} can handle this index correctly, but this binding will never 77 * be reported to {@link XmlOutput} through {@link #beginStartTag}. 78 * 79 * <p> 80 * One pecurilar behavior of a {@link NamespaceContextImpl} object is that it tries 81 * to define redundant xmlns="" on the root element. Implementations of {@link XmlOutput} 82 * is encouraged to check for this and avoid generating redundant namespace declarations. 83 * 84 * 85 * 86 * <h2>Call Sequence</h2> 87 * <p> 88 * {@link XMLSerializer} calls the writer methods in the following order: 89 * 90 * <pre> 91 * CALLSEQUENCE := {@link #startDocument startDocument} ELEMENT {@link #endDocument endDocument} 92 * | ELEMENT // for fragment 93 * 94 * ELEMENT := {@link #beginStartTag beginStartTag} {@link #attribute attribute}* {@link #endStartTag endStartTag} CONTENTS {@link #endTag endTag} 95 * 96 * CONTENTS := (ELEMENT | {@link #text text})* 97 * </pre> 98 * 99 * TODO: for FI, consider making attribute values from Strings to CharSequences. 100 * 101 * @author Kohsuke Kawaguchi 102 */ 103 public interface XmlOutput { 104 // 105 // 106 // Contracts 107 // 108 // 109 /** 110 * Called at the very beginning. 111 * 112 * @param serializer 113 * the {@link XMLSerializer} that coordinates this whole marshalling episode. 114 * @param fragment 115 * true if we are marshalling a fragment. 116 */ 117 public void startDocument(XMLSerializer serializer, boolean fragment, int[] nsUriIndex2prefixIndex, NamespaceContextImpl nsContext) throws IOException, SAXException, XMLStreamException; 118 119 /** 120 * Called at the very end. This is the last method to be invoked. 121 * 122 * @param fragment 123 * false if we are writing the whole document. 124 */ 125 public void endDocument(boolean fragment) throws IOException, SAXException, XMLStreamException; 126 127 /** 128 * Writes a start tag. 129 * 130 * <p> 131 * At this point {@link NamespaceContextImpl} holds namespace declarations needed for this 132 * new element. 133 * 134 * <p> 135 * This method is used for writing tags that are indexed. 136 */ 137 public void beginStartTag(Name name) throws IOException, XMLStreamException; 138 139 public void beginStartTag(int prefix, String localName) throws IOException, XMLStreamException; 140 141 public void attribute( Name name, String value ) throws IOException, XMLStreamException; 142 143 /** 144 * @param prefix 145 * -1 if this attribute does not have a prefix 146 * (this handling differs from that of elements.) 147 */ 148 public void attribute( int prefix, String localName, String value ) throws IOException, XMLStreamException; 149 150 public void endStartTag() throws IOException, SAXException; 151 152 public void endTag(Name name) throws IOException, SAXException, XMLStreamException; 153 154 public void endTag(int prefix, String localName) throws IOException, SAXException, XMLStreamException; 155 156 /** 157 * Writes XML text with character escaping, if necessary. 158 * 159 * @param value 160 * this string can contain characters that might need escaping 161 * (such as {@code '&' or '>'}) 162 * @param needsSeparatingWhitespace 163 */ 164 public void text( String value, boolean needsSeparatingWhitespace ) throws IOException, SAXException, XMLStreamException; 165 166 /** 167 * Writes XML text with character escaping, if necessary. 168 * 169 * @param value 170 * this string can contain characters that might need escaping 171 * (such as {@code '&' or '>'}) 172 * @param needsSeparatingWhitespace 173 */ 174 public void text( Pcdata value, boolean needsSeparatingWhitespace ) throws IOException, SAXException, XMLStreamException; 175 }