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Deserializer (JAXRPC API) - JBoss 4.0.1 sp1 jaxrpc API Documentation 英文版文档


org.apache.axis.encoding
Interface Deserializer

All Superinterfaces:
Callback, javax.xml.rpc.encoding.Deserializer, Serializable
All Known Implementing Classes:
DeserializerImpl

public interface Deserializer
extends javax.xml.rpc.encoding.Deserializer, Callback

This interface describes the AXIS Deserializer. A compliant implementiation must extend either the AXIS SoapHandler (org.apache.axis.message.SOAPHandler) or the AXIS DeserializerImpl (org.apache.axis.encoding.DeserializerImpl)

The DeserializerImpl provides a lot of the default behavior including the support for id/href. So you may want to try extending it as opposed to extending SoapHandler.

An Axis compliant Deserializer must provide one or more of the following methods:

public <constructor>(Class javaType, QName xmlType) public <constructo>()

This will allow for construction of generic factories that introspect the class to determine how to construct a deserializer. The xmlType, javaType arguments are filled in with the values known by the factory.


Method Summary
 boolean componentsReady()
          Some deserializers (ArrayDeserializer) require all of the component values to be known before the value is complete.
 void endElement(String namespace, String localName, DeserializationContext context)
          endElement is called when the end element tag is reached.
 javax.xml.namespace.QName getDefaultType()
           
 Object getValue()
          Get the deserialized value.
 Object getValue(Object hint)
          If the deserializer has component values (like ArrayDeserializer) this method gets the specific component via the hint.
 Vector getValueTargets()
          Get the Value Targets of the Deserializer.
 void moveValueTargets(Deserializer other)
          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.

 void onEndElement(String namespace, String localName, DeserializationContext context)
          onEndElement is called by endElement.
 SOAPHandler onStartChild(String namespace, String localName, String prefix, Attributes attributes, DeserializationContext context)
          onStartChild is called on each child element.
 void onStartElement(String namespace, String localName, String prefix, Attributes attributes, DeserializationContext context)
          This method is invoked after startElement when the element requires deserialization (i.e.
 void registerValueTarget(Target target)
          For deserializers of non-primitives, the value may not be known until later (due to multi-referencing).
 void removeValueTargets()
          Remove the Value Targets of the Deserializer.
 void setChildValue(Object value, Object hint)
          If the deserializer has component values (like ArrayDeserializer) this method sets the specific component via the hint.
 void setDefaultType(javax.xml.namespace.QName qName)
          In some circumstances an element may not have a type attribute, but a default type qname is known from information in the container.
 void setValue(Object value)
          Set the deserialized value.
 void startElement(String namespace, String localName, String qName, Attributes attributes, DeserializationContext context)
          This method is invoked when an element start tag is encountered.
 void valueComplete()
          The valueComplete() method is invoked when the end tag of the element is read.
 
Methods inherited from interface javax.xml.rpc.encoding.Deserializer
getMechanismType
 
Methods inherited from interface org.apache.axis.encoding.Callback
setValue
 

Method Detail

getValue

public Object getValue()
Get the deserialized value.

Returns:
Object representing deserialized value or null

setValue

public void setValue(Object value)
Set the deserialized value.

Parameters:
value - Object representing deserialized value

getValue

public Object getValue(Object hint)
If the deserializer has component values (like ArrayDeserializer) this method gets the specific component via the hint. The default implementation returns null.

Returns:
Object representing deserialized value or null

setChildValue

public void setChildValue(Object value,
                          Object hint)
                   throws SAXException
If the deserializer has component values (like ArrayDeserializer) this method sets the specific component via the hint. The default implementation does nothing.

Parameters:
value - Object representing deserialized value or null
Throws:
SAXException

setDefaultType

public void setDefaultType(javax.xml.namespace.QName qName)
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.


getDefaultType

public javax.xml.namespace.QName getDefaultType()

registerValueTarget

public void registerValueTarget(Target target)
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.

Parameters:
target - Target

getValueTargets

public Vector getValueTargets()
Get the Value Targets of the Deserializer.

Returns:
Vector of Target objects or null

removeValueTargets

public void removeValueTargets()
Remove the Value Targets of the Deserializer.


moveValueTargets

public void moveValueTargets(Deserializer other)
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.

Parameters:
other - is the Deserializer to copy targets from.

componentsReady

public boolean componentsReady()
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.


valueComplete

public void valueComplete()
                   throws SAXException
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)

Throws:
SAXException

startElement

public void startElement(String namespace,
                         String localName,
                         String qName,
                         Attributes attributes,
                         DeserializationContext context)
                  throws SAXException
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.

Parameters:
namespace - is the namespace of the element
localName - is the name of the element
qName - is the prefixed qName of the element
attributes - are the attributes on the element...used to get the type
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, set(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.

Throws:
SAXException

onStartElement

public void onStartElement(String namespace,
                           String localName,
                           String prefix,
                           Attributes attributes,
                           DeserializationContext context)
                    throws SAXException
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.

Parameters:
namespace - is the namespace of the element
localName - is the name of the element
prefix - is the prefix of the element
attributes - are the attributes on the element...used to get the type
context - is the DeserializationContext
Throws:
SAXException

onStartChild

public SOAPHandler onStartChild(String namespace,
                                String localName,
                                String prefix,
                                Attributes attributes,
                                DeserializationContext context)
                         throws SAXException
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.

Parameters:
namespace - is the namespace of the child element
localName - is the local name of the child element
prefix - is the prefix used on the name of the child element
attributes - are the attributes of the child element
context - is the deserialization context.
Returns:
is a Deserializer to use to deserialize a child (must be a derived class of SOAPHandler) or null if no deserialization should be performed.
Throws:
SAXException

endElement

public void endElement(String namespace,
                       String localName,
                       DeserializationContext context)
                throws SAXException
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.

Parameters:
namespace - is the namespace of the child element
localName - is the local name of the child element
context - is the deserialization context
Throws:
SAXException

onEndElement

public void onEndElement(String namespace,
                         String localName,
                         DeserializationContext context)
                  throws SAXException
onEndElement is called by endElement. It is not called if the element has an href.

Parameters:
namespace - is the namespace of the child element
localName - is the local name of the child element
context - is the deserialization context
Throws:
SAXException


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