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/*
* Copyright (c) 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.api.client.xml;
import com.google.api.client.util.ClassInfo;
import com.google.api.client.util.FieldInfo;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import org.xmlpull.v1.XmlSerializer;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
/**
* XML utilities.
*
*
* Upgrade warning: in prior version 1.2, there was a global static field {@code parserFactory},
* which is now removed.
*
*
* @since 1.0
* @author Yaniv Inbar
*/
public class Xml {
/** XML pull parser factory. */
private static XmlPullParserFactory factory;
private static synchronized XmlPullParserFactory getParserFactory()
throws XmlPullParserException {
if (factory == null) {
factory = XmlPullParserFactory.newInstance(
System.getProperty(XmlPullParserFactory.PROPERTY_NAME), null);
factory.setNamespaceAware(true);
}
return factory;
}
/**
* Returns a new XML serializer.
*
* @throws IllegalArgumentException if encountered an {@link XmlPullParserException}
*/
public static XmlSerializer createSerializer() {
try {
return getParserFactory().newSerializer();
} catch (XmlPullParserException e) {
throw new IllegalArgumentException(e);
}
}
/** Returns a new XML pull parser. */
public static XmlPullParser createParser() throws XmlPullParserException {
return getParserFactory().newPullParser();
}
/**
* Shows a debug string representation of an element data object of key/value pairs.
*
* It will make up something for the element name and XML namespaces. If those are known, it is
* better to use {@link XmlNamespaceDictionary#toStringOf(String, Object)}.
*
* @param element element data object of key/value pairs ({@link GenericXml}, {@link Map}, or any
* object with public fields)
*/
public static String toStringOf(Object element) {
return new XmlNamespaceDictionary().toStringOf(null, element);
}
private static void parseValue(String stringValue,
Field field,
Object destination,
GenericXml genericXml,
Map destinationMap,
String name) {
if (field == null) {
if (genericXml != null) {
genericXml.set(name, parseValue(stringValue, null));
} else if (destinationMap != null) {
destinationMap.put(name, parseValue(stringValue, null));
}
} else {
Class fieldClass = field.getType();
if (Modifier.isFinal(field.getModifiers()) && !FieldInfo.isPrimitive(fieldClass)) {
throw new IllegalArgumentException("final sub-element fields are not supported");
}
Object fieldValue = parseValue(stringValue, fieldClass);
FieldInfo.setFieldValue(field, destination, fieldValue);
}
}
/**
* Customizes the behavior of XML parsing. Subclasses may override any methods they need to
* customize behavior.
*/
public static class CustomizeParser {
/**
* Returns whether to stop parsing when reaching the start tag of an XML element before it has
* been processed. Only called if the element is actually being processed. By default, returns
* {@code false}, but subclasses may override.
*
* @param namespace XML element's namespace URI
* @param localName XML element's local name
*/
public boolean stopBeforeStartTag(String namespace, String localName) {
return false;
}
/**
* Returns whether to stop parsing when reaching the end tag of an XML element after it has been
* processed. Only called if the element is actually being processed. By default, returns {@code
* false}, but subclasses may override.
*
* @param namespace XML element's namespace URI
* @param localName XML element's local name
*/
public boolean stopAfterEndTag(String namespace, String localName) {
return false;
}
}
/**
* Parses an XML element using the given XML pull parser into the given destination object.
*
*
* Requires the the current event be {@link XmlPullParser#START_TAG} (skipping any initial
* {@link XmlPullParser#START_DOCUMENT}) of the element being parsed. At normal parsing
* completion, the current event will either be {@link XmlPullParser#END_TAG} of the element being
* parsed, or the {@link XmlPullParser#START_TAG} of the requested {@code atom:entry}.
*
*
* @param parser XML pull parser
* @param destination optional destination object to parser into or {@code null} to ignore XML
* content
* @param namespaceDictionary XML namespace dictionary to store unknown namespaces
* @param customizeParser optional parser customizer or {@code null} for none
*/
public static void parseElement(XmlPullParser parser, Object destination,
XmlNamespaceDictionary namespaceDictionary, CustomizeParser customizeParser)
throws IOException, XmlPullParserException {
parseElementInternal(parser, destination, namespaceDictionary, customizeParser);
}
/**
* Returns whether the customize parser has requested to stop or reached end of document.
* Otherwise, identical to
* {@link #parseElement(XmlPullParser, Object, XmlNamespaceDictionary, CustomizeParser)} .
*/
private static boolean parseElementInternal(XmlPullParser parser, Object destination,
XmlNamespaceDictionary namespaceDictionary, CustomizeParser customizeParser)
throws IOException, XmlPullParserException {
Class destinationClass = destination == null ? null : destination.getClass();
GenericXml genericXml = destination instanceof GenericXml ? (GenericXml) destination : null;
boolean isMap = genericXml == null && destination instanceof Map;
@SuppressWarnings("unchecked")
Map destinationMap = isMap ? (Map) destination : null;
ClassInfo classInfo = isMap || destination == null ? null : ClassInfo.of(destinationClass);
int eventType = parser.getEventType();
if (parser.getEventType() == XmlPullParser.START_DOCUMENT) {
eventType = parser.next();
}
if (eventType != XmlPullParser.START_TAG) {
throw new IllegalArgumentException(
"expected start of XML element, but got something else (event type " + eventType + ")");
}
// read namespaces declared on this XML element
int depth = parser.getDepth();
int nsStart = parser.getNamespaceCount(depth - 1);
int nsEnd = parser.getNamespaceCount(depth);
for (int i = nsStart; i < nsEnd; i++) {
String namespace = parser.getNamespaceUri(i);
// if namespace isn't already in our dictionary, add it now
if (namespaceDictionary.getAliasForUri(namespace) == null) {
String prefix = parser.getNamespacePrefix(i);
String originalAlias = prefix == null ? "" : prefix;
// find an available alias
String alias = originalAlias;
int suffix = 1;
while (namespaceDictionary.getUriForAlias(alias) != null) {
suffix++;
alias = originalAlias + suffix;
}
namespaceDictionary.set(alias, namespace);
}
}
// generic XML
if (genericXml != null) {
genericXml.namespaceDictionary = namespaceDictionary;
String name = parser.getName();
String namespace = parser.getNamespace();
String alias = namespaceDictionary.getAliasForUri(namespace);
genericXml.name = alias.length() == 0 ? name : alias + ":" + name;
}
// attributes
if (destination != null) {
int attributeCount = parser.getAttributeCount();
for (int i = 0; i < attributeCount; i++) {
String attributeName = parser.getAttributeName(i);
String attributeNamespace = parser.getAttributeNamespace(i);
String attributeAlias =
attributeNamespace.length() == 0 ? "" : namespaceDictionary.getAliasForUri(
attributeNamespace);
String fieldName = getFieldName(true, attributeAlias, attributeNamespace, attributeName);
Field field = isMap ? null : classInfo.getField(fieldName);
parseValue(parser.getAttributeValue(i),
field,
destination,
genericXml,
destinationMap,
fieldName);
}
}
Field field;
while (true) {
int event = parser.next();
switch (event) {
case XmlPullParser.END_DOCUMENT:
return true;
case XmlPullParser.END_TAG:
return customizeParser != null
&& customizeParser.stopAfterEndTag(parser.getNamespace(), parser.getName());
case XmlPullParser.TEXT:
// parse text content
if (destination != null) {
String textFieldName = "text()";
field = isMap ? null : classInfo.getField(textFieldName);
parseValue(parser.getText(),
field,
destination,
genericXml,
destinationMap,
textFieldName);
}
break;
case XmlPullParser.START_TAG:
if (customizeParser != null
&& customizeParser.stopBeforeStartTag(parser.getNamespace(), parser.getName())) {
return true;
}
if (destination == null) {
int level = 1;
while (level != 0) {
switch (parser.next()) {
case XmlPullParser.END_DOCUMENT:
return true;
case XmlPullParser.START_TAG:
level++;
break;
case XmlPullParser.END_TAG:
level--;
break;
}
}
continue;
}
// element
String namespace = parser.getNamespace();
String alias = namespaceDictionary.getAliasForUri(namespace);
String fieldName = getFieldName(false, alias, namespace, parser.getName());
field = isMap ? null : classInfo.getField(fieldName);
Class fieldClass = field == null ? null : field.getType();
boolean isStopped = false;
if (field == null && !isMap && genericXml == null || field != null
&& FieldInfo.isPrimitive(fieldClass)) {
int level = 1;
while (level != 0) {
switch (parser.next()) {
case XmlPullParser.END_DOCUMENT:
return true;
case XmlPullParser.START_TAG:
level++;
break;
case XmlPullParser.END_TAG:
level--;
break;
case XmlPullParser.TEXT:
if (level == 1) {
parseValue(parser.getText(),
field,
destination,
genericXml,
destinationMap,
fieldName);
}
break;
}
}
} else if (field == null || Map.class.isAssignableFrom(fieldClass)) {
// TODO: handle sub-field type
Map mapValue = ClassInfo.newMapInstance(fieldClass);
isStopped =
parseElementInternal(parser, mapValue, namespaceDictionary, customizeParser);
if (isMap) {
@SuppressWarnings("unchecked")
Collection