Examples of SipFactory

• javax.servlet.sip.SipFactory
• javax.sip.SipFactory
  The SipFactory is a singleton class which applications can use a single access point to obtain proprietary implementations of this specification. As the SipFactory is a singleton class there will only ever be one instance of the SipFactory. The single instance of the SipFactory can be obtained using the {@link SipFactory#getInstance()} method. If an instance of the SipFactoryalready exists it will be returned to the application, otherwise a new instance will be created. A peer implementation object can be obtained from the SipFactory by invoking the appropriate create method on the SipFactory e.g. to create a peer SipStack, an application would invoke the {@link SipFactory#createSipStack(Properties)} method.

  Naming Convention
  Note that the SipFactory utilises a naming convention defined by this specification to identify the location of proprietary objects that implement this specification. The naming convention is defined as follows:

  • The upper-level package structure referred to by the SipFactory with the attribute pathname can be used to differentiate between proprietary implementations from different SIP stack vendors. The pathname used by each SIP vendor must be the domain name assigned to that vendor in reverse order. For example, the pathname used by Sun Microsystem's would be com.sun.
  • The lower-level package structure and classname of a peer object is also mandated by this specification. The lowel-level package must be identical to the package structure defined by this specification and the classname is mandated to the interface name appended with the Impl post-fix. For example, the lower-level package structure and classname of a proprietary implementation of the javax.sip.SipStack interface must be javax.sip.SipStackImpl.

  Using this naming convention the SipFactory can locate a vendor's implementation of this specification without requiring an application to supply a user defined string to each create method in the SipFactory. Instead an application merely needs to identify the vendors SIP implementation it would like to use by setting the pathname of that vendors implementation.

  It follows that a proprietary implementation of a peer object of this specification can be located at:

  'pathname'.'lower-level package structure and classname'.

  For example an application can use the SipFactory to instantiate a NIST peer SipStack object by setting the pathname to gov.nist and calling the createSipStack method. The SipFactory would return a new instance of the SipStack object at the following location: gov.nist.javax.sip.SipStackImpl.java Because the space of domain names is managed, this scheme ensures that collisions between two different vendor's implementations will not happen. For example: a different vendor with a domain name 'bea.com' would have their peer SipStack object located at com.bea.javax.sip.SipStackImpl.java.

  Default Namespace:
  This specification defines a default namespace for the SipFactory, this namespace is the location of the Reference Implementation. The default namespace is gov.nist the author of the Reference Implementation, therefore the pathname will have the initial value of gov.nist for a new instance of the SipFactory. An application must set the pathname of the SipFactory on retrieval of a new instance of the factory in order to use a different vendors SIP stack from that of the Reference Implementation. An application can not mix different vendor's peer implementation objects. @author BEA Systems, NIST @version 1.2

Examples of javax.sip.SipFactory