java8 : annotation

java8to11/src/annotation/App.java

@@ -0,0 +1,29 @@
+package annotation;
+
+import java.util.Arrays;
+import java.util.List;
+
+
+@Chicken("양념")
+@Chicken("후라이드")
+@Chicken("간장")
+public class App {
+
+    public static void main(@Pizza String[] args) throws @Pizza RuntimeException {
+        List<@Pizza String> names = Arrays.asList("hello");
+        Chicken[] chickens = App.class.getAnnotationsByType(Chicken.class);
+        Arrays.stream(chickens).forEach(c -> System.out.println(c.value()));
+
+        System.out.println("========================================================");
+
+        ChickenContainer chickenContainer = App.class.getAnnotation(ChickenContainer.class);
+        Arrays.stream(chickenContainer.value()).forEach(c -> System.out.println(c.value()));
+    }
+
+    static class FeelsLikeChicken<@Pizza T> {
+
+        public static <@Pizza C> void print(@Pizza C c) {
+
+        }
+    }
+}

java8to11/src/annotation/Chicken.java

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+package annotation;
+
+import java.lang.annotation.*;
+
+@Retention(RetentionPolicy.RUNTIME)
+//@Target(ElementType.TYPE_PARAMETER) // type_parameter : 제네릭 타입에 @ 사용
+@Target(ElementType.TYPE_USE) // type_use : 타입을 사용하는 모든 곳에서 사용가능
+@Repeatable(ChickenContainer.class) // 어노테이션 중복 사용할 컨테이너 어노테이션 필요
+public @interface Chicken {
+    String value();
+}

java8to11/src/annotation/ChickenContainer.java

@@ -0,0 +1,13 @@
+package annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE_USE)
+public @interface ChickenContainer {
+
+    Chicken[] value();
+}

java8to11/src/annotation/Pizza.java

@@ -0,0 +1,11 @@
+package annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE_USE)
+public @interface Pizza {
+}