Contents - Cultural View

Java annotation 171
component.getAttributes().get("errordisplayval");
}
if(!Util.validateAGivenDate(date))
{
not, confirm"
}
}
}
@Unfinished(changedBy = "prabirk"
)
,value="whether to add message to context or
,priority=Priority.HIGH
FacesMessage message = new FacesMessage();
message.setSeverity(FacesMessage.SEVERITY_ERROR);
message.setSummary(errorLabel);
message.setDetail(errorLabel);
throw new ValidatorException(message);
The annotations are not method calls and will not, by themselves, do anything. Rather, the class object is passed to
the EJB implementation at run-time, which then extracts the annotations to generate an ORM.
Processing
When Java source code is compiled, annotations can be processed by compiler plug-ins called annotation processors.
Processors can produce informational messages or create additional Java source files or resources, which in turn may
be compiled and processed, but annotation processors cannot modify the annotated code itself. The Java compiler
conditionally stores annotation metadata in the class files if the annotation has a RetentionPolicy of CLASS or
RUNTIME. Later, the JVM or other programs can look for the metadata to determine how to interact with the
program elements or change their behavior.
History
The Java platform has 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. [3] Annotations became available in
the language itself beginning with version 1.5 of the JDK. 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.