Binary Compatibility
The standard enhancement interface defined by the JDO reference-enhancement contract provides binary compatibility among all enhancers and runtime environments. It requires that:
A class enhanced by the reference enhancer is usable with any JDO-compliant runtime environment.
A class enhanced by a JDO-compliant vendor’s enhancer is usable by the reference implementation’s runtime environment.
A class enhanced by a JDO-compliant vendor’s enhancer is usable by any other JDO-compliant runtime environment.
Furthermore, an enhanced class file can be shared concurrently in a JVM among several coresident JDO implementations.
An implementation’s runtime environment can determine whether a class was enhanced by its own enhancer. If it has, the implementation’s runtime environment can use any implementation-specific enhancements that were placed in the class file. Otherwise, it must use the standard reference-enhancement interface contract. Table 6-1 shows which enhancement interface a JDO runtime environment will use, based on the enhancer used to enhance the class.
Table 6-1. Enhancement interfaces used
Enhancer used | Reference runtime | Vendor A runtime | Vendor B runtime |
|---|---|---|---|
Reference enhancer | Reference enhancement | Reference enhancement | Reference enhancement |
Vendor A enhancer | Reference enhancement | Vendor A enhancement | Reference enhancement |
Vendor B enhancer | Reference enhancement | Reference enhancement | Vendor B enhancement |
You can distribute your classes in either their enhanced or unenhanced ...
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