- (id)objectForKey:(id)aKey;
- (NSMenuItem)itemWithTag:(NSInteger)aTag;
- (unichar)characterAtIndex:(NSUInteger)index;
- (NSString*)stringByAddingPercentEscapeUsingEncoding:(NSStringEncoding)encoding;
- (void)runInNewThread;
- (void)addAttribute:(NSString*)name value:(id)value range:(NSRange)aRange;

SEL selector = @selector(fontWithFamily:traits:weight:size)

import java.util.List;

public class PasswordUtils {
	
	@UseCase(id = 47, description = "passwords must contain at least one numeric")
	public boolean validatePassword(String password) {
		return (password.matches("\\w*\\d\\w*"));
	}
	
	@UseCase(id = 48)
	public String encryptPassword(String password) {
		return new StringBuilder(password).reverse().toString();
	}
	
	@UseCase(id = 49, description = "New passwords can't equal perviously used ones")
	public boolean checkForNewPassword(List prevPasswords, String password) {
		return !prevPasswords.contains(password);
	}
}

package net.atgame.annotation.usecase;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class UseCaseTracker {
	
	public static void trackUseCases(List useCases, Class cl) {
		for (Method m : cl.getDeclaredMethods()) {
			UseCase uc = m.getAnnotation(UseCase.class);
			if (uc != null) {
				System.out.println("Found Use Case:" + uc.id() + " " + uc.description());
				useCases.remove(new Integer(uc.id()));
			}
		}
		
		for (int i : useCases) {
			System.out.println("Warning: Missing use case~" + i);
		}
	}
	
	public static void main(String[] args) {
		List useCases = new ArrayList();
		Collections.addAll(useCases, 47, 48, 49, 50);
		trackUseCases(useCases, PasswordUtils.class);
	}
}

package net.atgame.annotation.database;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface DBTable {
	public String name() default "";
}

package net.atgame.annotation.database;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface SQLInteger {
	String name() default "";
	Constraints constraints() default @Constraints;
}

package net.atgame.annotation.database;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface SQLString {
	int value() default 0;
	String name() default "";
	Constraints constraints() default @Constraints;
}

package net.atgame.annotation.database;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Constraints {
	boolean primaryKey() default false;
	boolean allowNull() default true;
	boolean unique() default false;
}

package net.atgame.annotation.database;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

public class TableCreator {
	
	public static void main(String[] args) throws Exception {
		if (args.length < 1) {
			System.out.println("arguments: annotated classes");
			System.exit(0);
		}
		// 모든 엔티티 클래스를 읽음 
		for (String className : args) {
			Class cl = Class.forName(className);
			// 클래스 어노테이션 가져오기 
			DBTable dbTable = cl.getAnnotation(DBTable.class);
			if (dbTable == null) {
				System.out.println("No DBTable annotations in class " + className);
				continue;
			}
			String tableName = dbTable.name();
			
			if (tableName.length() < 1) {
				tableName = cl.getName().toUpperCase();
			}
			List columnDefs = new ArrayList();
			
			/// 필드목록 조회 
			for (Field field : cl.getDeclaredFields()) {
				String columnName = null;
				Annotation[] anns = field.getDeclaredAnnotations();
				if (anns.length < 1) {
					continue;
				}
				if (anns[0] instanceof SQLInteger)  {
					SQLInteger sInt = (SQLInteger)anns[0];
					if (sInt.name().length() < 1) {
						columnName = field.getName().toUpperCase();
					} else {
						columnName = sInt.name();
					}
					columnDefs.add(columnName + " INT" + getConstraints(sInt.constraints()));
				}
				if (anns[0] instanceof SQLString) {
					SQLString sString = (SQLString)anns[0];
					if (sString.name().length() < 1) {
						columnName = field.getName().toUpperCase();
					} else {
						columnName = sString.name();
					}
					columnDefs.add(columnName + " VARCHAR(" + sString.value() + ")" + getConstraints(sString.constraints()));
				}
				
			}
			StringBuilder createCommand = new StringBuilder("CREATE TABLE " + tableName + " (");
			for (String columnDef : columnDefs) {
				createCommand.append("\n " + columnDef + ",");
			}
			// 마지막 쉼표제거 
			String tableCreate = createCommand.substring(0, createCommand.length()-1) + ");";
			System.out.println("Table Creation SQL for " + className + " is :\n" + tableCreate);
		}
		
	}
	
	private static String getConstraints(Constraints con) {
		String constraints = "";
		if (!con.allowNull()) {
			constraints += " NOT NULL";
		}
		if (con.primaryKey()) {
			constraints += " PRIMARY KEY";
		}
		if (con.unique()) {
			constraints += " UNIQUE";
		}
		return constraints;
	}
}

<?xml version="1.0" encoding="UTF-8"?>

<map version="1.0"orientation="orthogonal"width="50"height="50"tilewidth="32"tileheight="32">

<tileset firstgid="1"name="tmw_desert_spacing"tilewidth="32"tileheight="32"spacing="1"margin="1">

<image source="tmw_desert_spacing.png"/>

</tileset>

<tileset firstgid="49"name="meta_tiles"tilewidth="32"tileheight="32"spacing="1"margin="1">

<image source="meta_tiles.png"/>

<tile id="0">

<properties>

<property name="Collidable"value="True"/>

</properties>

</tile>

<tile id="1">

<properties>

<property name="Collectable"value="True"/>

</properties>

</tile>

</tileset>

<layer name="Background"width="50"height="50">

<data encoding="base64"compression="gzip">

   H4sIAAAAAAAAA+3Uyw6CMBCF4a7EhYo7bwmp8ZIoiu//do6Ji4YgaZGWEf/Ft+uEczJkCmNMMTIbse1gpyC7ay+O4hrgJA4Kstd7hGbqMhOD7bGHDZxlH//T42bab1L9pt0V9riYz3epbHlT9vT92CoxEZmYKsjT5OxpIXKx9Hj7cAzdr87tMXSWJpmn+bvHLGAm5T+YR/TaXZWoxyqidcJ9fMsqyPCL2TBOVkEGAAAAAAAAAAAQxxPutT2PECcAAA==

</data>

</layer>

<objectgroup name="Objects" width="50" height="50">

<object name="SpawnPoint"x="77"y="432"/>

</objectgroup>

<layer name="Foreground"width="50"height="50">

<data encoding="base64"compression="gzip">

   H4sIAAAAAAAAA+3UQQ0AAAwCMZzMv8vJINlaBRceJNA17YDHbA9c5+cAAAAAAAAAfln1IckFECcAAA==

</data>

</layer>

<layer name="Meta"width="50"height="50">

<data encoding="base64"compression="gzip">

   H4sIAAAAAAAAA+3UUQqAIBAFQK9k9z9c9CeVZAm2ygwI/iy8VdeU1pM7ViSr9VGzfagZJZ/2bzOVNRH6OZSZ7s7+qSaK3vuIomWWZ5rz2fuomSUnV63/HP8wW2NFPu/I2ViTNwcAAAAAAOvaAbuBPXIQJwAA

</data>

</layer>

</map>

정의한 어노테이션을 다음과 같이 사용한다. 

단일 멤버를 갖을 경우에만 위와 같이 사용할 수 있다. 

3) 디폴트 값 설정하기 
 

디폴트값을 사용한 예는 다음과 같다. 

4) 메타-어노테이션

어노테이션에 사용되는 어노테이션으로 해당 어노테이션의 동작대상 및 보여타임을 결정한다. 

② @Retention 메타-어노테이션 

     자바컴파일러가 어노테이션을 다루는 방법과 관련이 있다.  소스파일, 클래스파일, 런타임 중 어느시점까지

    어노테이션을 보유하고 있을 것인지를 결정한다. 

위 세값 중 하나를 인자로 취해 다음과 같이 사용된다.