1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/jaxws_classes/com/sun/xml/internal/bind/v2/runtime/unmarshaller/XmlVisitor.java Wed Apr 27 01:27:09 2016 +0800
1.3 @@ -0,0 +1,153 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package com.sun.xml.internal.bind.v2.runtime.unmarshaller;
1.30 +
1.31 +import javax.xml.namespace.NamespaceContext;
1.32 +
1.33 +import org.xml.sax.SAXException;
1.34 +
1.35 +/**
1.36 + * Walks the XML document structure.
1.37 + *
1.38 + * Implemented by the unmarshaller and called by the API-specific connectors.
1.39 + *
1.40 + * <h2>Event Call Sequence</h2>
1.41 + *
1.42 + * The {@link XmlVisitor} expects the event callbacks in the following order:
1.43 + * <pre>
1.44 + * CALL SEQUENCE := startDocument ELEMENT endDocument
1.45 + * ELEMENT := startPrefixMapping ELEMENT endPrefixMapping
1.46 + * | startElement BODY endElement
1.47 + * BODY := text? (ELEMENT text?)*
1.48 + * </pre>
1.49 + * Note in particular that text events may not be called in a row;
1.50 + * consecutive characters (even those separated by PIs and comments)
1.51 + * must be reported as one event, unlike SAX.
1.52 + *
1.53 + * <p>
1.54 + * All namespace URIs, local names, and prefixes of element and attribute
1.55 + * names must be interned. qnames need not be interned.
1.56 + *
1.57 + *
1.58 + * <h2>Typed PCDATA</h2>
1.59 + * For efficiency, JAXB RI defines a few {@link CharSequence} implementations
1.60 + * that can be used as a parameter to the {@link #text(CharSequence)} method.
1.61 + * For example, see {@link Base64Data}.
1.62 + *
1.63 + * <h2>Error Handling</h2>
1.64 + * The visitor may throw {@link SAXException} to abort the unmarshalling process
1.65 + * in the middle.
1.66 + *
1.67 + * @author Kohsuke Kawaguchi
1.68 + */
1.69 +public interface XmlVisitor {
1.70 + /**
1.71 + * Notifies a start of the document.
1.72 + *
1.73 + * @param locator
1.74 + * This live object returns the location information as the parsing progresses.
1.75 + * must not be null.
1.76 + * @param nsContext
1.77 + * Some broken XML APIs can't iterate all the in-scope namespace bindings,
1.78 + * which makes it impossible to emulate {@link #startPrefixMapping(String, String)} correctly
1.79 + * when unmarshalling a subtree. Connectors that use such an API can
1.80 + * pass in additional {@link NamespaceContext} object that knows about the
1.81 + * in-scope namespace bindings. Otherwise (and normally) it is null.
1.82 + *
1.83 + * <p>
1.84 + * Ideally this object should be immutable and only represent the namespace URI bindings
1.85 + * in the context (those done above the element that JAXB started unmarshalling),
1.86 + * but it can also work even if it changes as the parsing progress (to include
1.87 + * namespaces declared on the current element being parsed.)
1.88 + */
1.89 + void startDocument(LocatorEx locator, NamespaceContext nsContext) throws SAXException;
1.90 + void endDocument() throws SAXException;
1.91 +
1.92 + /**
1.93 + * Notifies a start tag of a new element.
1.94 + *
1.95 + * namespace URIs and local names must be interned.
1.96 + */
1.97 + void startElement(TagName tagName) throws SAXException;
1.98 + void endElement(TagName tagName) throws SAXException;
1.99 +
1.100 + /**
1.101 + * Called before {@link #startElement} event to notify a new namespace binding.
1.102 + */
1.103 + void startPrefixMapping( String prefix, String nsUri ) throws SAXException;
1.104 + /**
1.105 + * Called after {@link #endElement} event to notify the end of a binding.
1.106 + */
1.107 + void endPrefixMapping( String prefix ) throws SAXException;
1.108 +
1.109 + /**
1.110 + * Text events.
1.111 + *
1.112 + * <p>
1.113 + * The caller should consult {@link TextPredictor} to see
1.114 + * if the unmarshaller is expecting any PCDATA. If the above is returning
1.115 + * false, the caller is OK to skip any text in XML. The net effect is
1.116 + * that we can ignore whitespaces quickly.
1.117 + *
1.118 + * @param pcdata
1.119 + * represents character data. This object can be mutable
1.120 + * (such as {@link StringBuilder}); it only needs to be fixed
1.121 + * while this method is executing.
1.122 + */
1.123 + void text( CharSequence pcdata ) throws SAXException;
1.124 +
1.125 + /**
1.126 + * Returns the {@link UnmarshallingContext} at the end of the chain.
1.127 + *
1.128 + * @return
1.129 + * always return the same object, so caching the result is recommended.
1.130 + */
1.131 + UnmarshallingContext getContext();
1.132 +
1.133 + /**
1.134 + * Gets the predictor that can be used for the caller to avoid
1.135 + * calling {@link #text(CharSequence)} unnecessarily.
1.136 + */
1.137 + TextPredictor getPredictor();
1.138 +
1.139 + interface TextPredictor {
1.140 + /**
1.141 + * Returns true if the visitor is expecting a text event as the next event.
1.142 + *
1.143 + * <p>
1.144 + * This is primarily intended to be used for optimization to avoid buffering
1.145 + * characters unnecessarily. If this method returns false and the connector
1.146 + * sees whitespace it can safely skip it.
1.147 + *
1.148 + * <p>
1.149 + * If this method returns true, all the whitespaces are considered significant
1.150 + * and thus need to be reported as a {@link XmlVisitor#text} event. Furthermore,
1.151 + * if the element has no children (like <foo/>), then it has to be reported
1.152 + * an empty {@link XmlVisitor#text} event.
1.153 + */
1.154 + boolean expectText();
1.155 + }
1.156 +}
