Exploring Advanced Language Features - Beginning Java 7 - page 258

Processing Annotations

Itisnotenoughtodeclareanannotationtypeandusethattypetoannotatesourcecode.
Unless you do something specific with those annotations, they remain dormant. One
way to accomplish something specific is to write an application that processes the an-
notations. Listing 3-49 ' s StubFinder application does just that.

Listing 3-49. The StubFinder application

import java.lang.reflect.Method;

class StubFinder
{

public static void main(String[] args) throws Exception
{

if (args.length != 1)
{

System.err.println("usage: java StubFinder

classfile");
return;

}
Method[]

methods =

Class.forName(args[0]).getMethods();
for (int i = 0; i < methods.length; i++)
if (methods[i].isAnnotationPresent(Stub.class))
{

Stub stub = meth-

ods[i].getAnnotation(Stub.class);
String[] components = stub.value().split(",");
System.out.println("Stub ID = "+compon-

ents[0]);

System.out.println("Stub Date = "+compon-

ents[1]);

System.out.println("Stub Developer = "+compon-

ents[2]);

System.out.println();

}