JAXB episode compilation with include does not work

问题

I have 2 schemas A, B. I'm reusing some A elements in B.

I do not use namespaces.

I'm using

<groupId>org.jvnet.jaxb2.maven2</groupId>
<artifactId>maven-jaxb2-plugin</artifactId>
<version>0.9.0</version>

I have have defined an inclusion of schema A in schema B as:

<xs:include schemaLocation="classpath:my.schema.A.xsd"/>

and the catalog as

REWRITE_SYSTEM "classpath:my.schema.A.xsd" "maven:my.schema:schema-a!/A.xsd"

The jaxb configuration goes:

<configuration>
    <generatePackage>my.schema.b</generatePackage>
    <schemaIncludes>
        <includes>B.xsd</includes>
    </schemaIncludes>
    <episodes>
        <episode>
            <groupId>my.schema</groupId>
            <artifactId>schema-a</artifactId>
        </episode>
    </episodes>
    <catalog>src/main/catalog/catalog.cat</catalog>
</configuration>

The issue is that whenever I specify the episode dependency the schema does not generate any classes even though it contains some B elements I want to generate the classes for.

[INFO] Parsing input schema(s)...
[INFO] Compiling input schema(s)...
[INFO] Cleaning package directories.
[INFO] Finished execution.

When I remove the episode it works well and generates classes for schema A as well - which I indeed want to avoid.

Do you have any suggestions?

A sample was published in Jaxb episodic compilation

回答1:

Ok, I've checked your example. The problem is that you don't use namespaces.

Check your META-INF/sub-jaxb.episode file:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<jaxb:bindings version="2.1" xmlns:jaxb="http://java.sun.com/xml/ns/jaxb">
  <jaxb:bindings scd="x-schema::">
    <jaxb:schemaBindings map="false">
      <jaxb:package name="schema.episode.a"/>
    </jaxb:schemaBindings>
    <jaxb:bindings scd="person">
      <jaxb:class ref="schema.episode.a.Person"/>
    </jaxb:bindings>
  </jaxb:bindings>
</jaxb:bindings>

You see this <jaxb:bindings scd="x-schema::"> and then <jaxb:schemaBindings map="false">. This basically tells XJC "don't map anything in the empty namespace". Since your second schema (b.xsd) also does not use namespaces, when you use a.xsd's episode file (binding above), you suppress generation of code for b.xsd as well.

To sum it up, when using episodes/separate schema compilation you can't put schemas with one namespace into different episodes. This is exactly the issue with include.

This is not a bug in the maven-jaxb2-plugin. I would not also call it a bug in XJC. It's just how episodes work by default.

See my pull request here, it demonstrates episodic compilation, when namespaces are handled accordingly.

回答2:

Author of the maven-jaxb2-plugin here.

My guess would be that your episode says something like "don't compile namespaces A and B". Please check the binding file inside META-INF in your JAR.

This is pretty advanced usage, there's quite a number of points where this can go wrong. You use:

catalogs
Maven artifact-based schema resolution
episodes

Catalogs and episodes are XJC features, Maven resolution comes from the maven-jaxb2-plugin. We should try to single out what fails:

Try it just with episodes - extract your schemas and compile "as is", without catalogs and resolver
Just catalogs - extract schema and rewrite to local dirs instead of maven:
Try maven:my.schema:schema-a!/A.xsd as schema location without episodes and catalogs

Obviously another three combinations to try.

If you provide a sample project, I'll investigate (but not within the next 10 days). The best would be to file an issue. I'll be moving the plugin to GitHub so this would be a good place:

https://github.com/highsource/maven-jaxb2-plugin

来源：https://stackoverflow.com/questions/25728801/jaxb-episode-compilation-with-include-does-not-work

标签

java

xml

xjc

maven-jaxb2-plugin

jaxb-episode