Using FML with WebLogic Tuxedo Connector
The following sections discuss the Field Manipulation Language (FML) and describe how the WebLogic Tuxedo Connector uses FML.
Overview of FML
Note: For more information about using FML, see Programming a BEA Tuxedo Application Using FML.
FML is a set of java language functions for defining and manipulating storage structures called fielded buffers. Each fielded buffer contains attribute-value pairs in fields. For each field:
There are two types of FML:
The WebLogic Tuxedo Connector FML API
The FML application program interface (API) is provided by the WebLogic Tuxedo Connector jatmi.jar file. The details of the FML API implementation are documented in the index.html file included doc directory of your WebLogic Tuxedo Connector distribution.
Note: The WebLogic Tuxedo Connector implements a subset of FML functionality. For example, views are not supported.
FML Field Table Administration
Note: For more information on field tables, see the index.html file included doc directory of your WebLogic Tuxedo Connector distribution for references on the FldTbl and the mkfldclass32 classes.
Field tables are generated in a manner similar to Tuxedo field tables. The field tables are text files that provide the field name definitions, field types, and identification numbers that are common between the two systems. To interoperate with a Tuxedo system using FML, the following steps are required:
For example: Your Tuxedo distribution contains a bank application example called bankapp. It contains a file called bankflds that has the following structure:
#Copyright (c) 1990 Unix System Laboratories, Inc.
#All rights reserved
#ident "@(#) apps/bankapp/bankflds $Revision: 1.3 $"
# Fields for database bankdb
# name number type flags comments
ACCOUNT_ID 110 long - -
ACCT_TYPE 112 char - -
ADDRESS 109 string - -
public final class bankflds
/** number: 110 type: long */
public final static int ACCOUNT_ID = 33554542;
/** number: 112 type: char */
public final static int ACCT_TYPE = 67108976;
/** number: 109 type: string */
public final static int ADDRESS = 167772269;
/** number: 117 type: float */
The result is a bankflds.class file. When loaded, the WebLogic Tuxedo Connector uses the class file to add, retrieve and delete field entries from an FML32 field.
tBridge XML/FML Translation
The <translateFML> element is used to indicate if FML translation is performed on the message payload. There are two types of FML translation: FLAT and NO.
Note: The data type specified must be FLAT or NO. If any other data type is specified, the redirection fails.
The message payload is translated using the WebLogic Tuxedo Connector internal FML/XML translator. Fields are converted field-by-field values without knowledge of the message structure (hierarchy) and repeated grouping.
In order to convert an FML buffer to XML, the tBridge pulls each instance of each field in the FML buffer, converts it to a string, and places it within a tag consisting of the field name. All of these fields are placed within a tag consisting of the service name. For example, an FML buffer consisting of the following fields:
ADDRESS CENTRAL CITY
The resulting XML buffer would be:
No translation is used. The tBridge maps a JMS TextMessage into a Tuxedo TypedBuffer (TypedString) and vice versa depending on the direction of the redirection. JMS BytesMessage are mapped into Tuxedo TypedBuffer (TypedCarray) and vice versa.
Remember to consider the following information when working with FML:
Copyright © 2001 BEA Systems, Inc. All rights reserved.