rocks.xmpp.core.stanza.model

Class AbstractIQ

java.lang.Object

rocks.xmpp.core.stanza.model.Stanza

rocks.xmpp.core.stanza.model.AbstractIQ

Direct Known Subclasses:

IQ, IQ

public abstract class AbstractIQ
extends Stanza

The implementation of the <iq/> stanza.

8.2.3. IQ Semantics

Info/Query, or IQ, is a "request-response" mechanism, similar in some ways to the Hypertext Transfer Protocol [HTTP]. The semantics of IQ enable an entity to make a request of, and receive a response from, another entity. The data content of the request and response is defined by the schema or other structural definition associated with the XML namespace that qualifies the direct child element of the IQ element (see Section 8.4), and the interaction is tracked by the requesting entity through use of the 'id' attribute. Thus, IQ interactions follow a common pattern of structured data exchange such as get/result or set/result (although an error can be returned in reply to a request if appropriate)

To enforce these semantics, the following rules apply:

1. The 'id' attribute is REQUIRED for IQ stanzas.
2. The 'type' attribute is REQUIRED for IQ stanzas. The value MUST be one of the following; if not, the recipient or an intermediate router MUST return a <bad-request/> stanza error (Section 8.3.3.1).
   • get -- The stanza requests information, inquires about what data is needed in order to complete further operations, etc.
   • set -- The stanza provides data that is needed for an operation to be completed, sets new values, replaces existing values, etc.
   • result -- The stanza is a response to a successful get or set request.
   • error -- The stanza reports an error that has occurred regarding processing or delivery of a get or set request (see Section 8.3).
3. An entity that receives an IQ request of type "get" or "set" MUST reply with an IQ response of type "result" or "error". The response MUST preserve the 'id' attribute of the request (or be empty if the generated stanza did not include an 'id' attribute).
4. An entity that receives a stanza of type "result" or "error" MUST NOT respond to the stanza by sending a further IQ response of type "result" or "error"; however, the requesting entity MAY send another request (e.g., an IQ of type "set" to provide obligatory information discovered through a get/result pair).
5. An IQ stanza of type "get" or "set" MUST contain exactly one child element, which specifies the semantics of the particular request.
6. An IQ stanza of type "result" MUST include zero or one child elements.
7. An IQ stanza of type "error" MAY include the child element contained in the associated "get" or "set" and MUST include an <error/> child.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractIQ.Type Represents a <iq/> 'type' attribute.

Method Summary

Modifier and Type	Method and Description
<T> T	getExtension(Class<T> type) Gets an extension by type.
AbstractIQ.Type	getType() Gets the type.
boolean	isRequest() Returns if this is a request IQ, i.e. of type get or set.
boolean	isResponse() Returns true, if this IQ is a response (either a positive result or an error).
void	setExtension(Object extension) Deprecated. Use constructor.
String	toString()

Methods inherited from class rocks.xmpp.core.stanza.model.Stanza

createError, createError, getError, getFrom, getId, getLanguage, getTo, setError, setFrom, setId, setLanguage, setTo, withFrom

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

getType

public final AbstractIQ.Type getType()

Gets the type.

Returns:

The type.

getExtension

public final <T> T getExtension(Class<T> type)

Description copied from class: Stanza

Gets an extension by type.

Specified by:

getExtension in class Stanza

Type Parameters:

T - The type.

Parameters:

type - The class.

Returns:

The extension or null.

toString

public final String toString()

Overrides:

toString in class Stanza

setExtension

@Deprecated
public final void setExtension(Object extension)

Deprecated. Use constructor.

Sets the extension.

Parameters:

extension - The extension.

isRequest

public final boolean isRequest()

Returns if this is a request IQ, i.e. of type get or set.

Returns:

True if this is a get or set IQ.

isResponse

public final boolean isResponse()

Returns true, if this IQ is a response (either a positive result or an error).

Returns:

If this is a result or error IQ.