I want to create an auto-generated resource file similar to R from android. I know how to do the parsing and creation of the file and essentially creating a new class file. What I don’t know how to do is start this auto-generation process.
So, using eclipse (although if there is a way to make this happen in an agnostic fashion, I would prefer it), how can I trigger an auto-generation session to read a properties file and create a .java file holding static variables and the “keys” from this parsed file, that I can then reference from my code?
A few examples of how to generate java source files have already been provided. It should be relatively easy to read the properties file and invoke one of these APIs.
To trigger the code generation process, you need to add a custom build step. With Ant, just add a custom task. And then hook it up to an Eclipse Builder: project Properties -> Builders -> New.
Subsequently, Eclipse should find and refresh this file on its own. If it doesn’t, then check your configs: Preferences -> General -> Workspace -> find “Refresh using native hooks or polling” and similar ones and check them. (Note that I’m not 100% sure that this last part will work.)
The path of least resistance is to run this build step separately. If your properties file is not changing that often, then it shouldn’t be that big a deal. This is similar to what you’d do if you use Protocol Buffers, JAXB, wsdl2java, etc. If you want everything to work magically like R.java does, then you probably have to do something a little more complicated:
– Try to use Eclipse Builder options to control when the Ant task is executed
– If you can’t figure that out, then I’d check out how Eclipse hooks up to the above projects (that is, to Protocol Buffers, JAXB, wsdl2java, etc.)
– Look at the ADT custom PreCompilerBuilder class
– Check out the build-helper-plugin