Chapter 3 Classes and Methods
in the Enterprise Connector Business Object API Package
The Enterprise Connector Business Object (MCBO) API contains one package, com.sun.mep.connector.api, that developers must use. This chapter
summarizes the classes contained within this package:
The API documentation is included in the MEP client bundle. In the directory
where you unzipped the client bundle (see the Sun Java System Mobile Enterprise Platform 1.0 Installation Guide for
details), it is in the directory sjsmep-client-1_0_02-fcs/doc/ecbo/api.
The BusinessObject Class
Table 3–1 lists the constructor
and methods belonging to the BusinessObject class, the
base class for all business objects. Business objects are the entities synchronized
with client applications. Each business object instance is identified by a
name, which is also used to name the file that holds the object on the mobile
client. Business objects are created by business object providers; see The BusinessObjectProvider Class for details.
Table 3–1 Class
com.sun.mep.connector.api.BusinessObject
|
Method
|
Description
|
|
BusinessObject(T bobjectProvider)
|
Constructor that takes the BusinessObjectProvider for
the business object as its argument.
|
|
public abstract void deserialize(byte[] data)
|
Deserializes a business object from a byte array.
|
|
public T getBusinessObjectProvider()
|
Returns a reference to the business object provider associated with
this object.
|
|
public abstract <T extends BusinessObject> DeleteCommand<T>
getDeleteCommand()
|
Returns a command that when executed can delete this business object
from a back end.
|
|
public abstract java.lang.String getExtension()
|
Returns the default extension for business objects of this type. Extensions
are used by the files holding these objects and must be part of the contract
with clients. That is, clients and connectors must use the same extension
for the same type of business object. Concrete subclasses should redefine
this method.
|
|
public abstract <T extends BusinessObject> InsertCommand<T>
getInsertCommand()
|
Returns a command that when executed can insert this business object
into a back end.
|
|
public long getLastModified()
|
Returns a timestamp indicating the last time this business object was
modified. The timestamp represents the number of milliseconds since “the
epoch,” namely January 1, 1970, 00:00:00 GMT.
|
|
public java.lang.String getName()
|
Returns the name of this business object. Names must be unique identifiers.
|
|
public abstract <T extends BusinessObject> UpdateCommand<T>
getUpdateCommand()
|
Returns a command that when executed can update this business object
in a back end.
|
|
public abstract byte[] serialize()
|
Serializes a business object into a byte array.
|
|
public void setLastModified(long millis)
|
Sets a timestamp indicating the last time this business object was modified.
The timestamp must represent the number of milliseconds since “the epoch,”
namely January 1, 1970, 00:00:00 GMT.
|
|
public void setName(java.lang.String name)
|
Sets the name of this business object. Names must be unique identifiers.
|
The BusinessObjectProvider Class
Table 3–2 lists the constructor
and methods belonging to the BusinessObjectProvider class.
This provider class for instances of BusinessObject
serves multiple purposes:
-
It can be used to retrieve all the business objects from a
back end by calling the getBusinessObjects() method.
-
It can be used to create new business objects by calling the newBusinessObject() method.
-
It provides access to a transaction manager and a session
context. See The TransactionManager Class and The SessionContext Class for more information.
An instance of this class is created for each synchronization session.
Use the methods initialize() and terminate() to
allocate and free session resources.
Table 3–2 Class
com.sun.mep.connector.api.BusinessObjectProvider
|
Method
|
Description
|
|
public BusinessObjectProvider()
|
No-argument constructor.
|
|
public abstract java.util.List<T> getBusinessObjects()
|
Returns a complete list of the business objects available in the back
end associated with this provider. This is in essence a query method for all
the instances in the back end.
|
|
public abstract java.lang.String getRepositoryName()
|
Returns the name of the repository holding these objects.
|
|
public SessionContext getSessionContext()
|
Returns the session context associated with this provider.
|
|
public <U extends BusinessObjectProvider> TransactionManager<U>
getTransactionManager()
|
Returns the transaction manager associated with this provider, or null
if no transaction manager has been set. If null is returned, transactions
are not supported by this provider.
|
|
public void initialize()
|
This method is called right after an instance of this class is created.
You can use it to allocate resources for the duration of a synchronization
session. Other uses of this method include back-end authentication. Credentials
needed for authentication are available from the SessionContext,
which you can access by calling getSessionContext().
|
|
public abstract T newBusinessObject()
|
Returns a fresh instance of a business object.
|
|
public void setSessionContext(SessionContext context)
|
Sets the session context for this provider.
|
|
public void terminate()
|
This method is called when a synchronization session is about to be
terminated. Use this method to free any resources allocated by this object.
|
The Command Class
Table 3–3 lists the constructor
and methods belonging to the Commandclass. This class
is the base class for all business object commands. The classes that extend
this class are described in The DeleteCommand Class, The InsertCommand Class, and The UpdateCommand Class.
Table 3–3 Class
com.sun.mep.connector.api.Command
|
Method
|
Description
|
|
public Command(T bobject)
|
Constructor that takes a business object argument.
|
|
public abstract void execute()
|
Executes this command against a back end. Unchecked exceptions, such
as java.lang.RuntimeException, can be used to report
errors.
|
|
public T getBusinessObject()
|
Returns the business object on which this command is executed.
|
The DeleteCommand Class
Table 3–4 lists the constructor
and method belonging to the DeleteCommand class. This
class is the base class for delete business object commands. It deletes a
business object from a back end.
Table 3–4 Class
com.sun.mep.connector.api.DeleteCommand
|
Method
|
Description
|
|
public DeleteCommand(T bobject)
|
Constructor that takes a business object argument.
|
|
public abstract void execute()
|
Executes this command against a back end. Unchecked exceptions, such
as java.lang.RuntimeException, can be used to report
errors.
|
The InsertCommand Class
Table 3–5 lists the constructor
and method belonging to the InsertCommand class. This class
is the base class for insert business object commands. It inserts a business
object into a back-end.
Table 3–5 Class
com.sun.mep.connector.api.InsertCommand
|
Method
|
Description
|
|
public InsertCommand(T bobject)
|
Constructor that takes a business object argument.
|
|
public abstract void execute()
|
Executes this command against a back end. Unchecked exceptions, such
as java.lang.RuntimeException, can be used to report
errors.
|
The SessionContext Class
Table 3–6 lists the constructor
and methods belonging to the SessionContext class. This
class stores contextual information about the session in which a BusinessObjectProvider is instantiated. This information includes credentials for logging
into an EIS/EAI system or a database as well as well as properties associated
with an Enterprise Connector..
Table 3–6 Class
com.sun.mep.connector.api.SessionContext
|
Method
|
Description
|
|
public SessionContext(java.lang.String username, java.lang.String
password)
|
Two-argument constructor that accepts username and password credentials.
|
|
public java.util.Map<java.lang.String, java.lang.String>
getParameters()
|
Returns all properties specified in the Admin Console's definition for
this Enterprise Connector.
|
|
public java.lang.String getPassword()
|
Returns the password used to log into the Enterprise Connector.
|
|
public java.lang.String getUsername()
|
Returns the user name used to log into the Enterprise Connector.
|
|
public void setParameter(java.lang.String name, java.lang.String
value)
|
Stores a name and value pair in the internal map.
|
The TransactionManager Class
Table 3–7 lists the constructor
and methods belonging to the TransactionManager class.
This class provides the transaction manager for a business object provider
class. It supports methods for starting, stopping, and aborting back-end transactions.
Table 3–7 Class
com.sun.mep.connector.api.TransactionManager
|
Method
|
Description
|
|
public TransactionManager(T bobjectProvider)
|
Constructor that creates a new TransactionManager for
the specified business object provider.
|
|
public void abortTransaction()
|
Rolls back the current transaction on the back-end system. By default,
this operation is a no-op.
|
|
public void beginTransaction()
|
Starts a new transaction on the back-end system. All business object
updates, deletes and inserts will be executed in a transaction. By default,
this operation is a no-op.
|
|
public void endTransaction()
|
Ends the current transaction on the back-end system. All business object
updates, deletes and inserts will be executed in a transaction. By default,
this operation is a no-op.
|
|
public T getBusinessObjectProvider()
|
Returns the business object manager associated with this transaction
manager.
|
The UpdateCommand Class
Table 3–8 lists the constructor
and method belonging to the UpdateCommand class. This
class is the base class for update business object commands. It updates a
business object in a back end.
Table 3–8 Class
com.sun.mep.connector.api.UpdateCommand
|
Method
|
Description
|
|
public UpdateCommand(T bobject)
|
Constructor that takes a business object argument.
|
|
public abstract void execute()
|
Executes this command against a back end. Unchecked exceptions, such
as java.lang.RuntimeException, can be used to report
errors.
|
Ladda ner denna bok i PDF (714 KB)