DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Refcards Trend Reports Events Over 2 million developers have joined DZone. Join Today! Thanks for visiting DZone today,
Edit Profile Manage Email Subscriptions Moderation Admin Console How to Post to DZone Article Submission Guidelines
View Profile
Sign Out
Refcards
Trend Reports
Events
Zones
Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones AWS Cloud
by AWS Developer Relations
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones
AWS Cloud
by AWS Developer Relations
Building Scalable Real-Time Apps with AstraDB and Vaadin
Register Now

Trending

  • How To Design Reliable IIoT Architecture
  • Chaining API Requests With API Gateway
  • Tomorrow’s Cloud Today: Unpacking the Future of Cloud Computing
  • Cypress Tutorial: A Comprehensive Guide With Examples and Best Practices

Trending

  • How To Design Reliable IIoT Architecture
  • Chaining API Requests With API Gateway
  • Tomorrow’s Cloud Today: Unpacking the Future of Cloud Computing
  • Cypress Tutorial: A Comprehensive Guide With Examples and Best Practices
  1. DZone
  2. Coding
  3. Languages
  4. Reusing Generated JAXB Classes

Reusing Generated JAXB Classes

Blaise Doughan user avatar by
Blaise Doughan
·
Dec. 06, 11 · Interview
Like (0)
Save
Tweet
Share
14.24K Views

Join the DZone community and get the full member experience.

Join For Free
In this post I will demonstrate how to leverage the -episode XJC extension to reuse classes previously generated from.an XML schema.  This is useful when an XML schema is imported by other XML schemas and you do not want the same classes generated each time.

Imported Schema (Product.xsd)

The following XML schema represents basic information about a product.  Product is a common concept in this example domain so I have decided to define one representation that can be leveraged by other schemas, rather than having each schema define its own representation of product information.
<?xml version="1.0" encoding="UTF-8"?>
<schema
    xmlns="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://www.example.org/Product"
    xmlns:tns="http://www.example.org/Product"
    elementFormDefault="qualified">
    <element name="product">
        <complexType>
            <sequence>
                <element name="id" type="string"/>
                <element name="name" type="string"/>
            </sequence>
        </complexType>
    </element>
</schema>
Since multiple XML schemas import Product.xsd we can leverage episode files so that the classes corresponding to Product.xsd are only generated once.  The following XJC call demonstrates how to generate an episode file called product.episode along with the generated classes:
xjc -d out -episode product.episode Product.xsd
Importing Schema (ProductPurchaseRequest.xsd)

Below is an example of an XML schema that imports Product.xsd:
<?xml version="1.0" encoding="UTF-8"?>
<schema
    xmlns="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://www.example.org/ProductPurchaseRequest"
    xmlns:tns="http://www.example.org/ProductPurchaseRequest"
    xmlns:prod="http://www.example.org/Product"
    elementFormDefault="qualified">
    <import namespace="http://www.example.org/Product" schemaLocation="Product.xsd"/>
    <element name="purchase-request">
        <complexType>
            <sequence>
                <element ref="prod:product" maxOccurs="unbounded"/>
            </sequence>
        </complexType>
    </element>
</schema>
When we generate classes from this XML schema we will reference the episode file we created when we generated Java classes from Product.xsd.  If we do not specify the episode file then classes will be generated for both ProductPurchaseRequest.xsd and Product.xsd:
xjc -d out ProductPurchaseRequest.xsd -extension -b product.episode
Another Importing Schema (ProductQuoteRequest.xsd)

Below is another example of an XML schema that imports Product.xsd:
<?xml version="1.0" encoding="UTF-8"?>
<schema
    xmlns="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://www.example.org/ProductQuoteRequest"
    xmlns:tns="http://www.example.org/ProductQuoteRequest"
    xmlns:prod="http://www.example.org/Product"
    elementFormDefault="qualified">
    <import namespace="http://www.example.org/Product" schemaLocation="Product.xsd"/>
    <element name="quote">
        <complexType>
            <sequence>
                <element ref="prod:product"/>
            </sequence>
        </complexType>
    </element>
</schema>


Again when we generate classes from this XML schema we will reference the episode file we created when we generated Java classes from Product.xsd.

xjc -d out ProductQuoteRequest.xsd -extension -b product.episode
How Does it Work? (product.episode)

For those of you curious how this works.  The episode file generated by XJC is really just a standard JAXB bindings file that is used to customize the class generation.  This generated bindings/episode file contains entries that tells XJC that a class already exists for this type.  You could write this file by hand, but -episode flag to XJC does it for you.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<bindings version="2.1" xmlns="http://java.sun.com/xml/ns/jaxb">
  <!--
 
This file was generated by the JavaTM Architecture for XML Binding
(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6 See
<a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a>
Any modifications to this file will be lost upon recompilation of the
source schema.
Generated on: 2011.11.02 at 03:40:10 PM EDT
 
  -->
  <bindings scd="x-schema::tns"
    xmlns:tns="http://www.example.org/Product">
    <schemaBindings map="false"/>
    <bindings scd="tns:product">
      <class ref="org.example.product.Product"/>
    </bindings>
  </bindings>
</bindings>

 

 

From http://blog.bdoughan.com/2011/12/reusing-generated-jaxb-classes.html

Schema XML

Opinions expressed by DZone contributors are their own.

Trending

  • How To Design Reliable IIoT Architecture
  • Chaining API Requests With API Gateway
  • Tomorrow’s Cloud Today: Unpacking the Future of Cloud Computing
  • Cypress Tutorial: A Comprehensive Guide With Examples and Best Practices

Comments

Partner Resources

X

ABOUT US

  • About DZone
  • Send feedback
  • Careers
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 600 Park Offices Drive
  • Suite 300
  • Durham, NC 27709
  • support@dzone.com

Let's be friends: