design patterns : decorator

design-pattern/gof/src/decorator/after/App.java

@@ -0,0 +1,25 @@
+package decorator.after;
+
+public class App {
+
+    private static boolean enabledSpamFilter = true;
+
+    private static boolean enabledTrimming = true;
+
+    public static void main(String[] args) {
+        CommentService commentService = new DefaultCommentService();
+
+        if (enabledSpamFilter) {
+            commentService = new SpamFilteringCommentDecorator(commentService);
+        }
+
+        if (enabledTrimming) {
+            commentService = new TrimmingCommentDecorator(commentService);
+        }
+
+        Client client = new Client(commentService);
+        client.writeComment("오징어게임");
+        client.writeComment("보는게 하는거 보다 재밌을 수가 없지...");
+        client.writeComment("http://whiteship.me");
+    }
+}

design-pattern/gof/src/decorator/after/Client.java

@@ -0,0 +1,14 @@
+package decorator.after;
+
+public class Client {
+
+    private CommentService commentService;
+
+    public Client(CommentService commentService) {
+        this.commentService = commentService;
+    }
+
+    public void writeComment(String comment) {
+        commentService.addComment(comment);
+    }
+}

design-pattern/gof/src/decorator/after/CommentDecorator.java

@@ -0,0 +1,15 @@
+package decorator.after;
+
+public class CommentDecorator implements CommentService {
+
+    private CommentService commentService;
+
+    public CommentDecorator(CommentService commentService) {
+        this.commentService = commentService;
+    }
+
+    @Override
+    public void addComment(String comment) {
+        commentService.addComment(comment);
+    }
+}

design-pattern/gof/src/decorator/after/CommentService.java

@@ -0,0 +1,6 @@
+package decorator.after;
+
+public interface CommentService {
+
+    void addComment(String comment);
+}

design-pattern/gof/src/decorator/after/DefaultCommentService.java

@@ -0,0 +1,8 @@
+package decorator.after;
+
+public class DefaultCommentService implements CommentService {
+    @Override
+    public void addComment(String comment) {
+        System.out.println(comment);
+    }
+}

design-pattern/gof/src/decorator/after/SpamFilteringCommentDecorator.java

@@ -0,0 +1,18 @@
+package decorator.after;
+
+public class SpamFilteringCommentDecorator extends CommentDecorator {
+    public SpamFilteringCommentDecorator(CommentService commentService) {
+        super(commentService);
+    }
+
+    @Override
+    public void addComment(String comment) {
+        if (isNotSpam(comment)) {
+            super.addComment(comment);
+        }
+    }
+
+    private boolean isNotSpam(String comment) {
+        return !comment.contains("http");
+    }
+}

design-pattern/gof/src/decorator/after/TrimmingCommentDecorator.java

@@ -0,0 +1,16 @@
+package decorator.after;
+
+public class TrimmingCommentDecorator extends CommentDecorator {
+    public TrimmingCommentDecorator(CommentService commentService) {
+        super(commentService);
+    }
+
+    @Override
+    public void addComment(String comment) {
+        super.addComment(trim(comment));
+    }
+
+    private String trim(String comment) {
+        return comment.replace("...", "");
+    }
+}

design-pattern/gof/src/decorator/before/Client.java

@@ -0,0 +1,22 @@
+package decorator.before;
+
+public class Client {
+
+    private CommentService commentService;
+
+    public Client(CommentService commentService) {
+        this.commentService = commentService;
+    }
+
+    private void writeComment(String comment) {
+        commentService.addComment(comment);
+    }
+
+    public static void main(String[] args) {
+        Client client = new Client(new SpamFilteringCommentService());
+        client.writeComment("오징어게임");
+        client.writeComment("보는게 하는거 보다 재밌을 수가 없지...");
+        client.writeComment("http://whiteship.me");
+    }
+
+}

design-pattern/gof/src/decorator/before/CommentService.java

@@ -0,0 +1,7 @@
+package decorator.before;
+
+public class CommentService {
+    public void addComment(String comment) {
+        System.out.println(comment);
+    }
+}

design-pattern/gof/src/decorator/before/SpamFilteringCommentService.java

@@ -0,0 +1,16 @@
+package decorator.before;
+
+public class SpamFilteringCommentService extends CommentService {
+
+    @Override
+    public void addComment(String comment) {
+        boolean isSpam = isSpam(comment);
+        if (!isSpam) {
+            super.addComment(comment);
+        }
+    }
+
+    private boolean isSpam(String comment) {
+        return comment.contains("http");
+    }
+}

design-pattern/gof/src/decorator/before/TrimmingCommentService.java

@@ -0,0 +1,14 @@
+package decorator.before;
+
+public class TrimmingCommentService extends CommentService {
+
+    @Override
+    public void addComment(String comment) {
+        super.addComment(trim(comment));
+    }
+
+    private String trim(String comment) {
+        return comment.replace("...", "");
+    }
+
+}