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Using Pollinate currently requires that Eclipse be invoked with tools.jar on the boot class path by including something like the following on the command line: -Xbootclasspath/a:C:/java/jdk1.5.0_01/lib/tools.jar This makes Pollinate hard to use "out of the box", so it would be nice to make this unnecessary. The reason this is necessary is somewhat subtle. For the sake of speed, the Pollinate builder invokes APT (the Annotation Processing Tool included in the JDK) directly from the JVM executing Eclipse, as opposed to starting another JVM as would happen when invoking APT from the command line. This naturally means the main APT class is loaded using an Eclipse plug-in class loader. But APT creates its own class loader to load the annotation processor factories provided by the user. (For Pollinate, these are the factories contained in the Beehive JAR files that process control, page flow, and other annotations.) Because there are two class loaders in the picture, a ClassCastException occurs in the absence of the boot class path argument: APT checks (using instanceof) that each annotation processor factory implements the AnnotationProcessorFactory interface, but this fails because the version of this interface it checks against is the one loaded from tools.jar along with APT by the Eclipse plug-in class loader, while the factories implement the version loaded from the class loader created by APT. The only way to solve the problem is to ensure that the two class loaders have a common parent that has tools.jar on the path; hence the boot class path argument. (This essentially happens automatically when apt is run from the command line, because tools.jar is on the path of the app class loader that is the implicit ancestor of the class loader created by APT.)
In update 01 of JDK 1.5, a "process()" method was added to the main APT class that allows the annotation processor factory to be specified. An experimental version of the Pollinate builder using this entry point made the boot class path unnecessary, since the factory came from the same class loader (an Eclipse plug-in loader) as the main APT class. However, there are issues: the "process()" entry point accepts just one annotation processor factory, while for controls two factories are used as specified in controls.jar in the manifest services/com.sun.mirror.apt.AnnotationProcessorFactory file. The experimental builder tries to compensate by iterating over the factories, but it's not clear that this produces the same results as before. Also, it produces warning messages like warning: Annotation types without processors: [org.apache.beehive.controls.api.bean.ControlInterface, org.apache.beehive.controls.api.bean.ControlImplementation] A solution would be to create some sort of composite factory. But since Pollinate doesn't have access to tools.jar, which is needed to define such a factory (because it must implement AnnotationProcessorFactory), this leads to the problem of building a separate JAR file containing such a factory. We're tabling this for now, and will come back to it later.
