JAXB Bindings to schemas in a JAR

问题:

I'm using the maven jaxb2 plugin to generate Java classes, built from schemas in a jar. However, I'm not sure how to correctly locate to these schemas from a bindings file. If Iextract the schemas from the jar and drop them in the same directory as the bindings, all is well. However, this isn't a practical long term solution.

pom.xml:

<plugin>
 <groupId>org.jvnet.jaxb2.maven2</groupId>
  <artifactId>maven-jaxb2-plugin</artifactId>
  <version>0.8.1</version>
  <executions>
    <execution>
     <goals>
      <goal>generate</goal>
     </goals>
    </execution>
   </executions>
   <configuration>
    <schemas>
     <schema>
      <dependencyResource>
       <groupId>com.test</groupId>
       <artifactId>schemas</artifactId>
       <version>1.10-SNAPSHOT</version>
       <resource>schemas/schema.xsd</resource>
      </dependencyResource>
     </schema>
    </schemas>              
    <bindingDirectory>bindings</bindingDirectory>
    <generatePackage>test.package</generatePackage>
    <bindingIncludes>
     <include>*.xml</include>
    </bindingIncludes>
    <extension>true</extension>
   </configuration>
  </plugin>

bindings.xml:

<jxb:bindings xmlns:xs="http://www.w3.org/2001/XMLSchema" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns:jxb="http://java.sun.com/xml/ns/jaxb"
 xsi:schemaLocation="http://java.sun.com/xml/ns/jaxb ./bindingschema_2_1.xsd"
 version="2.1">

<jxb:bindings schemaLocation="classpath:/schemas/schema.xsd" node="/xs:schema">
  <jxb:bindings node="//xs:complexType[@name='AbstractChangeable']">
   <jxb:class implClass="com.test.AbstractEntity" />
  </jxb:bindings>
</jxb:bindings>

回答1:

What I'd like to have working here is something like:

<jaxb:bindings schemaLocation="maven:org.jvnet.jaxb2.maven2:maven-jaxb2-plugin-tests-po!/purchaseorder.xsd" node="/xs:schema">
    <jaxb:schemaBindings>
        <jaxb:package name="org.jvnet.jaxb2.maven2.tests.po"/>
    </jaxb:schemaBindings>      
</jaxb:bindings>

But it does not at the moment. Please file an issue, I'll try to fix it.

What does work now is SCD-based binding:

<jaxb:bindings scd="x-schema::po" xmlns:po="urn:po">
    <jaxb:schemaBindings>
        <jaxb:package name="org.jvnet.jaxb2.maven2.tests.po"/>
    </jaxb:schemaBindings>      
</jaxb:bindings>

So you don't actually need to bind based on a specific schema location, you can bind based on the namespace URI, which is theoretically better.

Practically I have an experience that SCD-bindings don't always work reliably.

UPDATE

See this link for more information SCD usage in JAXB.

回答2:

You need to use maven-dependency-plugin:unpack and then point maven-jaxb2-plugin to outputDirectory. In this case in binding file you need to say something like schemaLocation="../target/schemas/schema.xsd"

回答3:

I know this is an old question but I was struggling with the same problem. I found that doing inline bindings would solve the problem. You would no longer have any need for the binding file and the bindings would be carried over to projects depending on it.