multi-dependency

Example Multi Module Binding Generation

1. XML Catalogs

Generated Catalog Files

XML catalogs help xml parsers and XJC find imported or included XML Schema files. The model builder maven plugin is used to generate 3 sets of xml catalog files.

1. {project}/design-catalog.xml

This file will contains a mapping of all XLM schemata in the {project}/src/main/resources/{model.name} directory. This file can be used to configure design tools such as OxygenXML to resolve all model files across different module folders or even from the classpath.

2. {jar}/META-INF/{model.name}/catalog.xml

This file is a basic catalog file that can be used to directly reference the data files in the given model. However when working with modular models it is possible that 2 models have the same xsd file. In this situation the catalogs must allow to differentiate the imports by name.

3. {jar}/META-INF/common.xcat

When resolving multiple catalog files from the classpath e.g. catalog file reference in a cxf runtime module, having them all named a same will cause the module to fail loading resolve any subsequent files.

TODO: catalog generator should also support rewriteSystem formats:

<!DOCTYPE catalog
    PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"
         prefer="public">
    <rewriteSystem systemIdStartString="http://www.w3.org/1999/xlink" rewritePrefix="w3c"/>
</catalog>

It will rewrite all URIs starting with http://www.w3.org to start with w3c instead.

So the schema location http://www.w3.org/1999/xlink.xsd in the following import:

<import namespace="http://www.w3.org/1999/xlink"
    schemaLocation="http://www.w3.org/1999/xlink.xsd"/>

Will be turned into w3c/1999/xlink.xsd and finally resolved to a local file.

2. Episodes

3. Gotchas

Multiple Modules with Same Schema Names

The following describes how to setup models in different modules which may contain the same file names. Lets say model 1 and model 2 both contain a SomeSchema.xsd file.

Lets say we have a 3rd schema that wants to import SomeSchema.xsd from model1 and model2. Something like below will not work obviously.

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <!-- will never work -->
  <xsd:import namespace="urn:model1" schemaLocation="SomeSchema.xsd"/>
  <xsd:import namespace="urn:model2" schemaLocation="SomeSchema.xsd"/>
</xsd:schema>

We need to make sure that model 1 and 2 schemata are packaged in a folder that allows us to differentiate the 2 files by name. We also need to create a xml catalog file for each model that allows us to import these correctly.

Module for model 1

model1
  |
  +-- SomeSchema.xsd
  |
  +-- catalog.xml

Catalog file for model 1

<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
  <system systemId="http://www.oasis-open.org/committees/entity/release/1.1/catalog.dtd"
          uri="resource:org/apache/xml/resolver/etc/catalog.dtd"/>
  <systemSuffix systemIdSuffix="model1/SomeSchema.xsd" uri="SomeSchema.xsd"/>
</catalog>

Module for model 2

model2
  |
  +-- SomeSchema.xsd
  |
  +-- catalog.xml

Catalog file for model 2

<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
  <system systemId="http://www.oasis-open.org/committees/entity/release/1.1/catalog.dtd"
          uri="resource:org/apache/xml/resolver/etc/catalog.dtd"/>
  <systemSuffix systemIdSuffix="model2/SomeSchema.xsd" uri="SomeSchema.xsd"/>
</catalog>

Now we can import both schemata with the same file name into schema number 3 as below example by using the model1 and model2 catalog.xml files.

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
	<xsd:import namespace="urn:model1" schemaLocation="model1/SomeSchema.xsd"/>
	<xsd:import namespace="urn:model2" schemaLocation="model2/SomeSchema.xsd"/>
</xsd:schema>

The design-model-maven-plugin's catalog generator has a feature to automatically generate XML catalog files with xml schema folder offsets. Simply specify a systemIdPathOffset greater than 0 and the xml catalogs generated by the plugin will offset the path to the immediate parent folder where the schema resides in.

Example plugin execution

<plugin>
  <groupId>io.fares.maven.plugins</groupId>
  <artifactId>design-builder-maven-plugin</artifactId>
  <executions>
    <execution>
      <id>generate-catalog</id>
      <phase>process-resources</phase>
      <goals>
        <goal>catalog</goal>
      </goals>
      <configuration>
        <sourceDirectory>${project.build.outputDirectory}/META-INF</sourceDirectory>
        <targetCatalogFile>${project.build.outputDirectory}/META-INF/schema/catalog.xml</targetCatalogFile>
        <systemIdPathOffset>1</systemIdPathOffset>
        <includes>
          <include>**/*.xsd</include>
        </includes>
        <verbose>true</verbose>
      </configuration>
    </execution>
  </executions>
</plugin>

XSDL Gen

<plugin>
  <groupId>org.jvnet.jax-ws-commons</groupId>
  <artifactId>jaxws-maven-plugin</artifactId>
  <version>2.3</version>
  <configuration>
    <vmArgs>
        <vmArg>-Djavax.xml.accessExternalSchema=all</vmArg>
    </vmArgs>
  </configuration>
</plugin>

XJC with Hibernate Generation

https://github.com/highsource/hyperjaxb3/blob/master/ejb/tests/annox/pom.xml