JAXB (RI) libraries vs. JDK

Question

Using maven, there are a couple of plugins to support e.g. generation of JAXB classes from XSD, e.g. org.codehaus.mojo:jaxb2-maven-plugin and org.jvnet.jaxb2.maven2:maven-jaxb2-plugin. The newest version of those have dependencies to e.g. org.glassfish.jaxb:jaxb-xjc and org.glassfish.jaxb:jaxb-runtime (in version 2.2.11).

But I wonder what would happen if I used those to generate my classes from XSD but use JDK 8 only (which contains version 2.2.8) at runtime: wouldn't there be a risk that I get runtime errors?
So is it necessary or recommended to always use the jaxb-runtime corresponding to the jaxb-xjc version I used to generate my classes from XSD?

Of course I could simply override the dependencies to jaxb-xjc etc. and explicitly use version 2.2.8. But even then I wonder if I would get the same result as if I used JDK 8 xjc tool directly?

Answer 1

You have three phases:

• (1) generation of the schema-derived code
• (2) compilation of the schema-derived code
• (3) runtime

The most important that JAXB API you use to compile (2) is compatible with JAXB API you use in runtime (3). If this is not the case then you might compile code which uses some annotation which is later not available in the runtime. And you'll see the error first in the runtime.

As for (1) vs. (2), this is also necessary. If you generate with JAXB 2.2.x and use JAXB 2.1.x to compile, this will not necessarily work. But this is less critical as this will be a compilation error which you will be forced to correct.

So if you problem is just JAXB version used by the maven-jaxb2-plugin vs. JAXB version embedded in JDK, I wouldn't worry about this. As long as it compiles, you're as safe as you can ever be.