The Java annotationsplatform werehas always had various ad hoc annotation mechanisms - for example, the transient modifier, or the @deprecated javadoc tag. The general purpose annotation(also known as metadata) facility was introduced to the [[Java Community Process]] as JSR-175 in 2002 and approved in September 2004. This Annotationstype of annotation became available with the [[JDK]] version 1.5. The feature was added to the Java language through the specification. A provisional interface for compile-time annotation processing was provided by the apt tool in JDK version 1.5, and was formalized through JSR-269 and integrated into the [[javac]] compiler in version 1.6.
