Association | Java Web Services in a Nutshell

Association

javax.xml.registry.infomode

JAXR 1.0; JWSDP 1.0, J2EE 1.4

 public interface Association extends RegistryObject {  // Property Accessor Methods (by property name)  public abstract Concept getAssociationType(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract void setAssociationType(Concept   associationType   )        throws javax.xml.registry.JAXRException;  //L0  public abstract boolean isConfirmed(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract boolean isConfirmedBySourceOwner(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract boolean isConfirmedByTargetOwner(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract boolean isExtramural(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract RegistryObject getSourceObject(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract void setSourceObject(RegistryObject   srcObject   )        throws javax.xml.registry.JAXRException;  //L0  public abstract RegistryObject getTargetObject(  )        throws javax.xml.registry.JAXRException;  //L0  public abstract void setTargetObject(RegistryObject   targetObject   )        throws javax.xml.registry.JAXRException;  //L0  }

An Association represents an assertion of a relationship of some kind between two objects in the registry, one of which is referred to as the source object, and the other as the target object. To create an Association , use the LifeCycleManager createAssociation( ) method, which requires a reference to the target object and an association type. The source object is set by adding the Association to it using the RegistryObject addAssociation( ) method. As with other registry objects, an Association is not visible in the registry until it has been saved using the BusinessLifeCycleManager saveAssociations( ) method; in some cases, this is not sufficient to make the association visible, as described shortly.

The Association type is specified using a Concept . The JAXR specification defines an enumerated type containing a set of standard Association types. There is a full list of these types listed under "Associations" in Chapter 7. You can obtain the appropriate Concept for the type of association you would like to create using the findConceptByPath( ) method of BusinessQueryManager , which is described in the reference section for the Concept interface, later in this chapter. To form the path needed to locate the Concept , you must have the identifier of a ClassificationScheme called AssociationType , which represents the enumeration that defines all of the types. The following code extract demonstrates how to get this ClassificationScheme and then use it to find the Concept that represents the association type Uses . It is assumed that the variable bqm refers to an instance of BusinessQueryManager .

 ClassificationScheme types = bqm.findClassificationSchemeByName(null, "AssociationType"); String path = "/" + types.getKey(  ).getId(  ) + "/Uses"; Concept uses = bqm.findConceptByPath(path);

Some JAXR providers allow you to use the name of the enumeration in the path supplied to the findConceptByPath( ) method, thus removing the need to search for the ID of the ClassificationScheme . In this case, you can use the following, much simpler code:

 Concept uses = bqm.findConceptByPath("/AssociationType/Uses");

The next step is to create an Association by specifying the type and the target object. The following code uses the BusinessLifeCycleManager referred to by the variable blcm to create an association of type uses with an object referred to by the variable targetObject as its target:

 Association association = blcm.createAssociation(targetObject, uses);

Finally, to complete the association, add the Association object to the source object:

 sourceObject.addAssociation(association);

There is a distinction made in the API between the source and target objects because associations are directional. The Uses association type is an example of this the Assocation just created conveys the fact that the source object "uses" the target object, rather than the other way around. If, at some point in the future, the association needs to be broken, this can be done by removing it from the source object using the removeAssociation( ) method. The source and target objects and the association type can be obtained by calling the getSourceObject( ) , getTargetObject( ) , and getAssociationType( ) methods, respectively, and can be changed using the corresponding setter methods. Changing the source object using setSourceObject( ) implicitly removes the Association from the original source. Note that a registry object may be the source and/or target of any number of Association s at the same time. You can search for existing Association s using the findAssociations( ) and findCallerAssociations( ) methods of BusinessQueryManager .

Association s can be categorized as either intramural or extramural. An intramural Association is formed when the source and target objects are owned by the same registry User and the Association is created by that same User . Such an Association can be considered a correct factual assertion, and is therefore said to be confirmed as soon as it is created. An extramural Association is one in which at least one of the source and target objects in not owned by the User that creates it. Such an Association is unconfirmed, since it has not been agreed to by the owner of both objects and is not visible to other registry users until it is confirmed by them. The isExtramural( ) method can be used to determine the intramural or extramural status of an Association . An Association can be confirmed using the confirmAssociation( ) method of BusinessLifeCycleManager , and confirmation can be withdrawn using the unconfirmAssociation( ) method. To find out whether an extramural Association is confirmed, use the isConfirmed( ) , isConfirmedBySourceOwner( ) , and isConfirmedByTargetOwner( ) methods, which all return true when applied to an intramural Association .

Passed To

javax.xml.registry.BusinessLifeCycleManager.{confirmAssociation( ) , unConfirmAssociation( )} , RegistryObject.{addAssociation( ) , removeAssociation( )}

Returned By

javax.xml.registry.LifeCycleManager.createAssociation( )