Customizing XJC Bindings - Tutorial

In JAXB (Java Architecture for XML Binding), XJC (XML to Java Compiler) is a powerful tool that generates Java classes from XML schemas (XSD). While the default code generation provided by XJC is sufficient in most cases, you may need to customize the bindings to suit specific requirements. This tutorial will guide you through the process of customizing XJC bindings to modify the generated Java classes.

Step-by-Step Tutorial

Follow these steps to customize XJC bindings:

1. Create a separate XML file that contains the customization bindings. This file typically has the extension .xjb.
2. Open the customization bindings file in a text editor and define your customizations using XML syntax. These customizations can include renaming elements or attributes, specifying custom package names, modifying property names, etc.
3. Save the customization bindings file in the same directory as your XSD file.
4. Open a command prompt or terminal and navigate to the directory where your XSD file is located.
5. Execute the following command to generate the customized JAXB classes:

xjc -b your-customization.xjb your-schema.xsd

This command runs the xjc tool and instructs it to apply the customizations defined in the .xjb file to the XSD file, resulting in the generation of customized Java classes.

Once the command completes successfully, you will find the generated customized JAXB classes in the same directory as your XSD file.

Common Mistakes

• Not creating a separate .xjb file for customization.
• Incorrectly defining the customizations in the bindings file.
• Not specifying the correct file paths or names when executing the xjc command.

Frequently Asked Questions

Q1: Can I apply multiple customization files to the same XSD?

A1: Yes, you can apply multiple customization files to the same XSD by specifying them as separate -b options in the xjc command.

Q2: How can I rename an element in the generated Java class?

A2: To rename an element, use the <jxb:property name="newName" /> customization in your bindings file, where newName is the desired new name.

Q3: Can I specify a custom package name for the generated Java classes?

A3: Yes, you can specify a custom package name using the <jxb:package name="com.example.custom" /> customization in your bindings file. Replace com.example.custom with your desired package name.

Q4: How can I exclude an element from being generated in the Java class?

A4: To exclude an element, use the <jxb:bindings node="xpath-expression" /> customization in your bindings file, where xpath-expression is the XPath expression matching the element to exclude.

Q5: Can I customize the data types used in the generated Java classes?

A5: Yes, you can customize the data types by defining <jxb:javaType name="java-type" xmlType="xml-type" /> customizations in your bindings file, where java-type is the desired Java type and xml-type is the XML type to be mapped.

Summary

In this tutorial, you learned how to customize XJC bindings in JAXB to modify the generated Java classes from XML schemas. By creating a separate .xjb file and defining customizations, you can tailor the generated classes to meet specific requirements. Follow the step-by-step instructions outlined in this tutorial to customize XJC bindings effectively.