Java @Retention Example

@Retention 

@Retention annotation specifies how the marked annotation is stored:

RetentionPolicy.SOURCE – The marked annotation is retained only in the source level and is ignored by the compiler.
RetentionPolicy.CLASS – The marked annotation is retained by the compiler at compile time, but is ignored by the Java Virtual Machine (JVM).
RetentionPolicy.RUNTIME – The marked annotation is retained by the JVM so it can be used by the runtime environment.