/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* 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 org.apache.axis.encoding;
import org.apache.axis.Constants;
import org.apache.axis.Part;
import org.apache.axis.components.logger.LogFactory;
import org.apache.axis.message.EnvelopeHandler;
import org.apache.axis.message.MessageElement;
import org.apache.axis.message.SAX2EventRecorder;
import org.apache.axis.message.SAXOutputter;
import org.apache.axis.message.SOAPHandler;
import org.apache.axis.utils.Messages;
import org.apache.axis.soap.SOAPConstants;
import org.apache.commons.logging.Log;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.namespace.QName;
import java.io.StringWriter;
import java.util.HashSet;
import java.util.Vector;
/** The Deserializer base class.
*
* @author Glen Daniels (gdaniels@allaire.com)
* Re-architected for JAX-RPC Compliance by
* @author Rich Scheuerle (sche@us.ibm.com)
*/
public class DeserializerImpl extends SOAPHandler
implements javax.xml.rpc.encoding.Deserializer, Deserializer, Callback
{
protected static Log log =
LogFactory.getLog(DeserializerImpl.class.getName());
protected Object value = null;
// invariant member variable to track low-level logging requirements
// we cache this once per instance lifecycle to avoid repeated lookups
// in heavily used code.
private final boolean debugEnabled = log.isDebugEnabled();
// isEnded is set when the endElement is called
protected boolean isEnded = false;
protected Vector targets = null;
protected QName defaultType = null;
protected boolean componentsReadyFlag = false;
/**
* A set of sub-deserializers whose values must complete before our
* value is complete.
*/
private HashSet activeDeserializers = new HashSet();
protected boolean isHref = false;
protected boolean isNil = false; // xsd:nil attribute is set to true
protected String id = null; // Set to the id of the element
public DeserializerImpl() {
}
/**
* JAX-RPC compliant method which returns mechanism type.
*/
public String getMechanismType() {
return Constants.AXIS_SAX;
}
/**
* Get the deserialized value.
* @return Object representing deserialized value or null
*/
public Object getValue()
{
return value;
}
/**
* Set the deserialized value.
* @param value Object representing deserialized value
*/
public void setValue(Object value)
{
this.value = value;
}
/**
* If the deserializer has component values (like ArrayDeserializer)
* this method gets the specific component via the hint.
* The default implementation returns null.
* @return Object representing deserialized value or null
*/
public Object getValue(Object hint)
{
return null;
}
/**
* If the deserializer has component values (like ArrayDeserializer)
* this method sets the specific component via the hint.
* The default implementation does nothing.
* @param hint Object representing deserialized value or null
*/
public void setChildValue(Object value, Object hint) throws SAXException
{
}
public void setValue(Object value, Object hint) throws SAXException {
if (hint instanceof Deserializer) {
// This one's done
activeDeserializers.remove(hint);
// If we're past the end of our XML, and this is the last one,
// our value has been assembled completely.
if (componentsReady()) {
// Got everything we need, call valueComplete()
valueComplete();
}
}
}
/**
* In some circumstances an element may not have
* a type attribute, but a default type qname is known from
* information in the container. For example,
* an element of an array may not have a type= attribute,
* so the default qname is the component type of the array.
* This method is used to communicate the default type information
* to the deserializer.
*/
public void setDefaultType(QName qName) {
defaultType = qName;
}
public QName getDefaultType() {
return defaultType;
}
/**
* For deserializers of non-primitives, the value may not be
* known until later (due to multi-referencing). In such
* cases the deserializer registers Target object(s). When
* the value is known, the set(value) will be invoked for
* each Target registered with the Deserializer. The Target
* object abstracts the function of setting a target with a
* value. See the Target interface for more info.
* @param target
*/
public void registerValueTarget(Target target)
{
if (targets == null) {
targets = new Vector();
}
targets.addElement(target);
}
/**
* Get the Value Targets of the Deserializer.
* @return Vector of Target objects or null
*/
public Vector getValueTargets() {
return targets;
}
/**
* Remove the Value Targets of the Deserializer.
*/
public void removeValueTargets() {
if (targets != null) {
targets = null;
}
}
/**
* Move someone else's targets to our own (see DeserializationContext)
*
* The DeserializationContext only allows one Deserializer to
* wait for a unknown multi-ref'ed value. So to ensure
* that all of the targets are updated, this method is invoked
* to copy the Target objects to the waiting Deserializer.
* @param other is the Deserializer to copy targets from.
*/
public void moveValueTargets(Deserializer other)
{
if ((other == null) || (other.getValueTargets() == null)) {
return;
}
if (targets == null) {
targets = new Vector();
}
targets.addAll(other.getValueTargets());
other.removeValueTargets();
}
/**
* Some deserializers (ArrayDeserializer) require
* all of the component values to be known before the
* value is complete.
* (For the ArrayDeserializer this is important because
* the elements are stored in an ArrayList, and all values
* must be known before the ArrayList is converted into the
* expected array.
*
* This routine is used to indicate when the components are ready.
* The default (true) is useful for most Deserializers.
*/
public boolean componentsReady() {
return (componentsReadyFlag ||
(!isHref && isEnded && activeDeserializers.isEmpty()));
}
/**
* The valueComplete() method is invoked when the
* end tag of the element is read. This results
* in the setting of all registered Targets (see
* registerValueTarget).
* Note that the valueComplete() only processes
* the Targets if componentReady() returns true.
* So if you override componentReady(), then your
* specific Deserializer will need to call valueComplete()
* when your components are ready (See ArrayDeserializer)
*/
public void valueComplete() throws SAXException
{
if (componentsReady()) {
if (targets != null) {
for (int i = 0; i < targets.size(); i++) {
Target target = (Target) targets.get(i);
target.set(value);
if (debugEnabled) {
log.debug(Messages.getMessage("setValueInTarget00",
"" + value, "" + target));
}
}
// Don't need targets any more, so clear them
removeValueTargets();
}
}
}
public void addChildDeserializer(Deserializer dSer) {
// Keep track of our active deserializers. This enables us to figure
// out whether or not we're really done in the case where we get to
// our end tag, but still have open hrefs for members.
if (activeDeserializers != null) {
activeDeserializers.add(dSer);
}
// In concert with the above, we make sure each field deserializer
// lets us know when it's done so we can take it off our list.
dSer.registerValueTarget(new CallbackTarget(this, dSer));
}
/**
* Subclasses may override these
*/
/**
* This method is invoked when an element start tag is encountered.
* DeserializerImpl provides default behavior, which involves the following:
* - directly handling the deserialization of a nill value
* - handling the registration of the id value.
* - handling the registration of a fixup if this element is an href.
* - calling onStartElement to do the actual deserialization if not nill or href cases.
* @param namespace is the namespace of the element
* @param localName is the name of the element
* @param prefix is the prefix of the element
* @param attributes are the attributes on the element...used to get the type
* @param context is the DeserializationContext
*
* Normally a specific Deserializer (FooDeserializer) should extend DeserializerImpl.
* Here is the flow that will occur in such cases:
* 1) DeserializerImpl.startElement(...) will be called and do the id/href/nill stuff.
* 2) If real deserialization needs to take place DeserializerImpl.onStartElement will be
* invoked, which will attempt to install the specific Deserializer (FooDeserializer)
* 3) The FooDeserializer.startElement(...) will be called to do the Foo specific stuff.
* This results in a call to FooDeserializer.onStartElement(...) if startElement was
* not overridden.
* 4) The onChildElement(...) method is called for each child element. Nothing occurs
* if not overridden. The FooDeserializer.onStartChild(...) method should return
* the deserializer for the child element.
* 5) When the end tag is reached, the endElement(..) method is invoked. The default
* behavior is to handle hrefs/ids, call onEndElement and then call the Deserializer
* valueComplete method.
*
* So the methods that you potentially want to override are:
* onStartElement, onStartChild, componentsReady, setValue(object, hint)
* You probably should not override startElement or endElement.
* If you need specific behaviour at the end of the element consider overriding
* onEndElement.
*
* See the pre-existing Deserializers for more information.
*/
public void startElement(String namespace, String localName,
String prefix, Attributes attributes,
DeserializationContext context)
throws SAXException
{
super.startElement(namespace, localName, prefix, attributes, context);
// If the nil attribute is present and true, set the value to null
// and return since there is nothing to deserialize.
if (context.isNil(attributes)) {
value = null;
isNil = true;
return;
}
SOAPConstants soapConstants = context.getSOAPConstants();
// If this element has an id, then associate the value with the id.
// (Prior to this association, the MessageElement of the element is
// associated with the id. Failure to replace the MessageElement at this
// point will cause an infinite loop during deserialization if the
// current element contains child elements that cause an href back to this id.)
// Also note that that endElement() method is responsible for the final
// association of this id with the completed value.
id = attributes.getValue("id");
if (id != null) {
context.addObjectById(id, value);
if (debugEnabled) {
log.debug(Messages.getMessage("deserInitPutValueDebug00", "" + value, id));
}
context.registerFixup("#" + id, this);
}
String href = attributes.getValue(soapConstants.getAttrHref());
if (href != null) {
isHref = true;
Object ref = context.getObjectByRef(href);
if (debugEnabled) {
log.debug(Messages.getMessage(
"gotForID00",
new String[] {"" + ref, href, (ref == null ? "*null*" : ref.getClass().toString())}));
}
if (ref == null) {
// Nothing yet... register for later interest.
context.registerFixup(href, this);
return;
}
if (ref instanceof MessageElement) {
context.replaceElementHandler(new EnvelopeHandler(this));
SAX2EventRecorder r = context.getRecorder();
context.setRecorder(null);
((MessageElement)ref).publishToHandler((DefaultHandler) context);
context.setRecorder(r);
} else {
if( !href.startsWith("#") && defaultType != null && ref instanceof Part ){
//For attachments this is the end of the road-- invoke deserializer
Deserializer dser = context.getDeserializerForType(defaultType );
if(null != dser){
dser.startElement(namespace, localName,
prefix, attributes,
context);
ref = dser.getValue();
}
}
// If the ref is not a MessageElement, then it must be an
// element that has already been deserialized. Use it directly.
value = ref;
componentsReadyFlag = true;
valueComplete();
}
} else {
isHref = false;
onStartElement(namespace, localName, prefix, attributes,
context);
}
}
/**
* This method is invoked after startElement when the element requires
* deserialization (i.e. the element is not an href and the value is not nil.)
* DeserializerImpl provides default behavior, which simply
* involves obtaining a correct Deserializer and plugging its handler.
* @param namespace is the namespace of the element
* @param localName is the name of the element
* @param prefix is the prefix of the element
* @param attributes are the attributes on the element...used to get the type
* @param context is the DeserializationContext
*/
public void onStartElement(String namespace, String localName,
String prefix, Attributes attributes,
DeserializationContext context)
throws SAXException
{
// If I'm the base class, try replacing myself with an
// appropriate deserializer gleaned from type info.
if (this.getClass().equals(DeserializerImpl.class)) {
QName type = context.getTypeFromAttributes(namespace,
localName,
attributes);
// If no type is specified, use the defaultType if available.
// xsd:string is used if no type is provided.
if (type == null) {
type = defaultType;
if (type == null) {
type = Constants.XSD_STRING;
}
}
if (debugEnabled) {
log.debug(Messages.getMessage("gotType00", "Deser", "" + type));
}
// We know we're deserializing, but we don't have
// a specific deserializer. So create one using the
// attribute type qname.
if (type != null) {
Deserializer dser = context.getDeserializerForType(type);
if (dser == null) {
dser = context.getDeserializerForClass(null);
}
if (dser != null) {
// Move the value targets to the new deserializer
dser.moveValueTargets(this);
context.replaceElementHandler((SOAPHandler) dser);
// And don't forget to give it the start event...
boolean isRef = context.isProcessingRef();
context.setProcessingRef(true);
dser.startElement(namespace, localName, prefix,
attributes, context);
context.setProcessingRef(isRef);
} else {
throw new SAXException(
Messages.getMessage("noDeser00", "" + type));
}
}
}
}
/**
* onStartChild is called on each child element.
* The default behavior supplied by DeserializationImpl is to do nothing.
* A specific deserializer may perform other tasks. For example a
* BeanDeserializer will construct a deserializer for the indicated
* property and return it.
* @param namespace is the namespace of the child element
* @param localName is the local name of the child element
* @param prefix is the prefix used on the name of the child element
* @param attributes are the attributes of the child element
* @param context is the deserialization context.
* @return is a Deserializer to use to deserialize a child (must be
* a derived class of SOAPHandler) or null if no deserialization should
* be performed.
*/
public SOAPHandler onStartChild(String namespace, String localName,
String prefix, Attributes attributes,
DeserializationContext context)
throws SAXException
{
return null;
}
/**
* endElement is called when the end element tag is reached.
* It handles href/id information for multi-ref processing
* and invokes the valueComplete() method of the deserializer
* which sets the targets with the deserialized value.
* @param namespace is the namespace of the child element
* @param localName is the local name of the child element
* @param context is the deserialization context
*/
public final void endElement(String namespace, String localName,
DeserializationContext context)
throws SAXException
{
super.endElement(namespace, localName, context);
isEnded = true;
if (!isHref) {
onEndElement(namespace, localName, context);
}
// Time to call valueComplete to copy the value to
// the targets. First a call is made to componentsReady
// to ensure that all components are ready.
if (componentsReady()) {
valueComplete();
}
// If this element has an id, then associate the value with the id.
// Subsequent hrefs to the id will obtain the value directly.
// This is necessary for proper multi-reference deserialization.
if (id != null) {
context.addObjectById(id, value);
if (debugEnabled) {
log.debug(Messages.getMessage("deserPutValueDebug00", "" + value, id));
}
}
}
/**
* onEndElement is called by endElement. It is not called
* if the element has an href.
* @param namespace is the namespace of the child element
* @param localName is the local name of the child element
* @param context is the deserialization context
*/
public void onEndElement(String namespace, String localName,
DeserializationContext context)
throws SAXException
{
// If we only have SAX events, but someone really wanted a
// value, try sending them the contents of this element
// as a String...
// ??? Is this the right thing to do here?
if (this.getClass().equals(DeserializerImpl.class) &&
targets != null &&
!targets.isEmpty()) {
StringWriter writer = new StringWriter();
SerializationContext serContext =
new SerializationContext(writer,
context.getMessageContext());
serContext.setSendDecl(false);
SAXOutputter so = null;
so = new SAXOutputter(serContext);
context.getCurElement().publishContents(so);
if (!isNil) {
value = writer.getBuffer().toString();
}
}
}
}
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