3 Developing Oracle WebLogic Tuxedo Connector Service EJBs

The following sections provide information on how to create Oracle WebLogic Tuxedo Connector service EJBs:

Basic Service EJB Operation
Example Service EJB

Basic Service EJB Operation

A service application uses Java and JATMI primitives to provide the following tasks:

Access Service Information
Buffer Messages
Perform the Requested Service

Access Service Information

Use the TPServiceInformation class to access service information sent by the Oracle Tuxedo client to run the service.

Table 3-1 JATMI TPServiceInformation Primitives

Buffer Type	Description
getServiceData()	Use to return the service data sent from the Oracle Tuxedo Client.
getServiceFlags()	Use to return the service flags sent from the Oracle Tuxedo Client.
getServiceName()	Use to return the service name that was called.

Buffer Messages

Use the following TypedBuffers when sending and receiving messages between your application and Oracle Tuxedo:

Table 3-2 TypedBuffers

Buffer Type	Description
TypedString	Buffer type used when the data is an array of characters that terminates with the null character. Oracle Tuxedo equivalent: STRING.
TypedCArray	Buffer type used when the data is an undefined array of characters (byte array), any of which can be null. Oracle Tuxedo equivalent: CARRAY.
TypedFML	Buffer type used when the data is self-defined. Each data field carries its own identifier, an occurrence number, and possibly a length indicator. Oracle Tuxedo equivalent: FML.
TypedFML32	Buffer type similar to TypeFML but allows for larger character fields, more fields, and larger overall buffers. Oracle Tuxedo equivalent: FML32.
TypedXML	Buffer type used when data is an XML based message. Oracle Tuxedo equivalent: XML for Tuxedo Release 7.1 and higher.
TypedView	Buffer type used when the application uses a Java structure to define the buffer structure using a view description file. Tuxedo equivalent: VIEW
TypedView32	Buffer type similar to View but allows for larger character fields, more fields, and larger overall buffers. Oracle Tuxedo equivalent: VIEW32.
TypedXOctet	Buffer type used when the data is an undefined array of characters (byte array) any of which can be null. X_OCTET is identical in semantics to CARRAY. Oracle Tuxedo equivalent: X_OCTET.
TypedXCommon	Buffer type identical in semantics to View. Oracle Tuxedo equivalent: VIEW.
TypedXCType	Buffer type identical in semantics to View. Oracle Tuxedo equivalent: VIEW.
TypedMBString	Buffer type used when the data is a wide array of characters to support multi-byte characters. Oracle Tuxedo equivalent: MBSTRING.

Perform the Requested Service

Use Java code to express the logic required to provide your service.

Return Client Messages for Request/Response Communication

Use the TuxedoReply class setReplyBuffer() method to respond to client requests.

Use tpsend and tprecv for Conversational Communication

Note:

For more information on Conversational Communication, see Chapter 6, "Oracle WebLogic Tuxedo Connector JATMI Conversations."

Use the following JATMI primitives when creating conversational servers that communicate with Oracle Tuxedo clients:

Table 3-3 Oracle WebLogic Tuxedo Connector Conversational Client Primitives

Name	Operation
tpconnect	Use to establish a connection to an Oracle Tuxedo conversational service.
tpdiscon	Use to abort a connection and generate a TPEV_DISCONIMM event when executed by the process controlling the conversation.
tprecv	Use to receive data across an open connection from an Oracle Tuxedo application.
tpsend	Use to send data across a open connection to an Oracle Tuxedo application.

Example Service EJB

The following provides an example of the TolowerBean.java service EJB which receives a string argument, converts the string to all lower case, and returns the converted string to the client.

Example 3-1 Example Service EJB

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public Reply service(TPServiceInformation mydata) throws TPException {
     TypedString data;
     String lowered;
     TypedString return_data;

     log("service tolower called");

     data = (TypedString) mydata.getServiceData();
     lowered = data.toString().toLowerCase();
     return_data = new TypedString(lowered);

     mydata.setReplyBuffer(return_data);
     return (mydata);
} 
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