Customizing Message Code Generation
QuickFIX/J includes message libraries generated from standard FIX meta data XML files. However, there are several ways to customize code generation.
Modifying the Data Dictionary
The simplest customization is to modify one or more data dictionaries (e.g., FIX44.xml) and rebuild QuickFIX/J. This allows you to add custom fields, define new messages not included in the standard specification, and change whether fields are required or optional.
Advanced Customization (MessageCodeGenerator)
You can do more advanced customization using the quickfix.codegen.MessageCodeGenerator class. You can define code generation tasks (quickfix.codegen.MessageCodeGenerator.Task) that customize various aspects of the generation process.
| Property | Description |
|---|---|
specification | Path to the XML file containing the FIX meta data (e.g., /my/dir/CUSTOM_FIX.xml). |
transformDirectory | Path to the XSLT transforms used to generate the source code. |
outputBaseDirectory | The base directory where generated source code will be placed. |
messagePackage | The Java package for the generated messages (e.g., my.message.fix42). |
fieldPackage | The Java package for the generated fields. |
orderedFields | Generates message classes where regular body fields are ordered exactly as specified in the meta. Some exchanges require strict ordering. |
decimalGenerated | Generates BigDecimal for price, quantity, and similar fields instead of double. |
utcTimestampPrecision | The default UtcTimestampPrecision used during field code generation. |
To generate your own message library, create a program that uses MessageCodeGenerator to process your Task, or use the QFJ Maven/Ant scripts. You may also need to write a custom MessageFactory implementation and reference it in the session configuration.