IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with adapters

J2C data bindings

For J2C resource adapters, the data bindings are provided with the resource adapter, or they are generated by the tools. There are two specialized interfaces for J2C data bindings that are shown in this section.

The commonj.connector.runtime.RecordDataBinding interface, shown below, extends the basic interface and adds to it the javax.resource.cci.Record.

public interface RecordDataBinding extends DataBinding, javax.resource.cci.Record {
}

If the data binding is to be used with the Java EE Connector Architecture (J2C)-based service, it has to implement this interface. As a record, it can be passed to the resource adapter interaction's execute method with input and output.

If the resource adapter supports the javax.resource.cci.Streamable interface, as its view of the record argument passed to the execute method, the commonj.connector.runtime.StreamableDataBinding interface presented below can be used.

public interface StreamableDataBinding extends RecordDataBinding, Streamable {
}

When this data binding is passed to the resource adapter's execute method, it may use the Streamable interface directly, if implemented, without going through the data object.

public CustomerDataObject getCustomer(CustomerDataObject customer){

		ConnectionFactory connectionFactory = getConnectionFactory();

		// Create and configure InteractionSpec
		InteractionSpec interactionSpec = new EISInteractionSpec();
		interactionSpec.setProperty1(…);
		interactionSpec.setProperty2(…);
	
		// Create instance of the Interaction
		Connection connection = connectionFactory.getConnection();
		Interaction interaction = connection.createInteraction();
		
		// Instantiate data bindings 		RecordDataBinding inputBinding = new CustomerBindingImpl();
		RecordDataBinding outputBinding = new CustomerBindingImpl();
			
		// Set service argument on the input data binding 		inputBinding.setDataObject(customer);
		
		if(supportsInputOutputExecute)		
interaction.execute(interactionSpec,inputBinding,outputBinding);
		
		return (CustomerDataObject)outputBinding.getDataObject();

	}

The previous RecordDataBinding interface is not sufficient if the resource adapter supports the input only variant of the execute method on the interaction. This is because the execute method with only the input record argument returns the ‘native' result as a Common Client Interface (CCI) record. This record needs to be set on the data binding and then the converted data object can be retrieved.

The required functionality is provided by the commonj.connector.runtime.RecordHolderDataBinding interface shown below.

public interface RecordHolderDataBinding extends DataBinding {
	
	public javax.resource.cci.Record getRecord() throws DataBindingException;
	public void setRecord(javax.resource.cci.Record aRecord) 
			throws DataBindingException;}

If the Resource Adapter supports the input only variant of the execute method, the Data Binding provider needs to implement the previous interface.

public CustomerDataObject getCustomer(CustomerDataObject customer){

		ConnectionFactory connectionFactory = getConnectionFactory();

		// Create and configure InteractionSpec
		InteractionSpec interactionSpec = new EISInteractionSpec();
		interactionSpec.setProperty1(…);
		interactionSpec.setProperty2(…);
	
		// Create instance of the Interaction
		Connection connection = connectionFactory.getConnection();
		Interaction interaction = connection.createInteraction();
		
		// Instantiate data bindings 		RecordDataBinding inputBinding = new CustomerBindingImpl();
		RecordDataBinding outputBinding = new CustomerBindingImpl();
			
		// Set service argument on the input data binding 		inputBinding.setDataObject(customer);
		
		Record result = 	interaction.execute(interactionSpec,inputBinding);
      outputBinding.setRecord(result);
		
		return (CustomerDataObject)outputBinding.getDataObject();

	}

The second instance when the RecordHolderDataBinding interface must be implemented is for the inbound J2C communication. The listener interface is invoked by the resource adapter and the Message Driven Bean (MDB) implementing it is passed the ‘native' data. This data needs to be set on the data binding to be able to retrieve from its business object. If the listener argument and return are typed as javax.resource.cci.Record, the RecordHolderDataBinding is sufficient. If the listener argument(s) or return type is other than a CCI record, the following utility commonj.connector.runtime.InboundNativeDataRecord interface is provided.

public interface InboundNativeDataRecord extends Record {

	public Object[] getNativeData();
	public void setNativeData(Object[] data);}

An arbitrary number and types of arguments to the listener can be set on this interface, as the object array. The implementation, a CCI record, can then be set on the RecordHolderDataBinding interface thus passing all the listener arguments and allowing the data binding to retrieve arguments and create the business object. On the return, the data binding implementation sets the return value in the symmetric manner. The runtime then uses a get method, also returning an object array. The argument at index 0 is the return value to be returned to the invoker (resource adapter).

Access external services with adapters

Related concepts:
Pattern of accessing external services with adapters
Developing services with adapters
Simple adapter wizard
Migrating applications using previous adapter levels

Related tasks:
Configure and using adapters
Create a business object from a source file

Related reference:
A closer look at business objects from data structures
J2C imports and exports at run time
Trade-offs when developing adapter imports and exports
Considerations when using adapters
Considerations when refactoring
Contributing your own external service or data wizard plug-in
Limitations for adapter imports and exports