Frequently Asked Questions

General

1. Do I need to generate Runtime binding classes in addition to the JAXB classes produced with build-jaxb.xml?
2. Why am I getting a "unrecognized parameter -Xlegstar-code" when running build-jaxb.xml?
3. Why am I getting a "java.lang.LinkageError: JAXB 2.0 API is being loaded from the bootstrap classloader, but this RI (...) needs 2.1 API.?
4. Is it possible to use the JAXB implementation that comes with JRE 6 instead of the one that is distributed with LegStar?
5. How do I use the binding classes to perform my own mainframe to java and java to mainframe conversions?

General

Do I need to generate Runtime binding classes in addition to the JAXB classes produced with build-jaxb.xml?

This is a performance versus flexibility trade off. The runtime binding classes are faster but they need to be rebuilt (using build-coxb.xml) every time something changes. Please note that some other LegStar generators favor runtime binding classes over annotated JAXB classes.

[top]

---

Why am I getting a "unrecognized parameter -Xlegstar-code" when running build-jaxb.xml?

This is probably a classpath issue. XJC is not finding the LegStar Jaxbgen classes. Make sure the legstar-jaxbgen-nnn jar file is in the XJC classpathref. If you are running an older version of build-jaxb.xml (pre 1.0.1) with JRE 1.6 and above, you also need to modify the ant script from "com.sun.tools.xjc.XJCTask" to "com.sun.tools.xjc.XJC2Task".

This error also shows up if the JRE is too old (older than JRE 1.5). In this case, XJC fails to load the LegStar classes which needs JRE 1.5 at least.

[top]

---

Why am I getting a "java.lang.LinkageError: JAXB 2.0 API is being loaded from the bootstrap classloader, but this RI (...) needs 2.1 API.?

LegStar uses JAXB 2.1 but your JRE takes precedence. Older JRE 1.6 came with JAXB 2.0 which is not compatible with JAXB 2.1. You can use the JRE endorsement mechanism to overcome this.

[top]

---

Is it possible to use the JAXB implementation that comes with JRE 6 instead of the one that is distributed with LegStar?

The answer is it depends. At development time this is not possible because LegStar implements an XJC plugin. If XJC is loaded as part of the JRE, it won't find the LegStar plugin (unless you want to get into the rather complicated endorsement process). At runtime, if your JRE is more recent then 1.6 r4, then you can use the JRE implementation because it is JAXB 2.1 compliant.

[top]

---

How do I use the binding classes to perform my own mainframe to java and java to mainframe conversions?

Assuming you generated binding classes for a JAXB root class named MyClass, you get a MyClassTransformers class. To convert a java data object to mainframe bytes, you can use code similar to:

            /* Populate your JAXB object in getMyClass */
            MyClass myClass = getMyClass();
            /* Create an instance of the binding transformers */
            MyClassTransformers transformers = new MyClassTransformers();
            /* Convert Java to mainframe bytes */
            byte[] hostBytes = transformers.toHost(request, hostCharset);
      

To convert mainframe bytes to a java data object , you can use code similar to:

             /* Create an instance of the binding transformers */
            MyClassTransformers transformers = new MyClassTransformers();
            /* Convert Java to mainframe bytes */
            MyClass myClass = transformers.toJava(hostBytes, hostCharset);
      

[top]