To use the Google Annotations Gallery, download the gag-<version>.zip file
from http://code.google.com/p/gag/ and unzip.

You can find the annotations and supporting enumerations in gag.jar. If you
want to enforce the enforceable annotations, you can find the dynamic bytecode
instrumentation Java agent in gag-agent.jar.

To use the annotations, simply annotate your code with them and include
gag.jar in your classpath.

To use the Java agent: use at least JDK 5; use the -javaagent:gag-agent.jar
option; and put the agent-dependent jars in your classpath, like:

  java -javaagent:gag-agent.jar \
    -cp asm-3.1.jar:asm-commons-3.1.jar:google-collect-1.0.jar:gag.jar \
    MyAnnotatedClass

A demo can be run from ant by doing:

  ant run-demo