# A simple annotation processing example

This project demonstrates a simple annotation processor that is built with [Kobalt](http://beust.com/kobalt). The annotation processor allows you to generate a `Version` class containing a version number that is either read from a `Properties` file or directly defined in the annotation.

There are two modules in this project:

- The processor (`processor/`)
- The example using the processor (`example/`)

The `processor` project defines an annotation `@Version` that lets you specify a version number in two ways:

- Either provide a `value` for the version.
- Or you provide a `fileName` pointing to a `Properties` file. This file contains the version number either with the default key `version` or with your own key, which you can specify with the `propertyName` attribute.

For example:

```
@Version(fileName = "example/src/main/properties/version.properties",
    propertyName = "example.version")
public class A {
// ...
```

And the content of the `version.properties` file:

```
example.version=1.4
```

When the annotation processor is run, it generates a source file `GeneratedVersion.java` with a static field containing that version number.

The `example` project has a single class `Example` which is annotated with `@Version` and which then displays the value of the version from the `GeneratedVersion` generated class.

To build and run the example:

```

./kobaltw run

```

To install and run from Kobalt:

```

dependencies {
    apt("com.beust:version-processor:0.1")
}

```