spring core proxy : decorator pattern

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/DecoratorPatternTest.java

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+package com.example.proxy.pureproxy.decorator;
+
+import com.example.proxy.pureproxy.decorator.code.*;
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.Test;
+
+@Slf4j
+public class DecoratorPatternTest {
+
+    @Test
+    void noDecorator() {
+        Component component = new RealComponent();
+        DecoratorPatternClient client = new DecoratorPatternClient(component);
+        client.execute();
+    }
+
+    @Test
+    void decorate1() {
+        Component realComponent = new RealComponent();
+        Component messageDecorator = new MessageDecorator(realComponent);
+        DecoratorPatternClient client = new DecoratorPatternClient(messageDecorator);
+        client.execute();
+    }
+
+    @Test
+    void decorate2() {
+        Component realComponent = new RealComponent();
+        Component messageDecorator = new MessageDecorator(realComponent);
+        Component timeDecorator = new TimeDecorator(messageDecorator);
+        DecoratorPatternClient client = new DecoratorPatternClient(timeDecorator);
+        client.execute();
+    }
+}

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/code/Component.java

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+package com.example.proxy.pureproxy.decorator.code;
+
+public interface Component {
+    String operation();
+}

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/code/DecoratorPatternClient.java

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+package com.example.proxy.pureproxy.decorator.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class DecoratorPatternClient {
+
+    private final Component component;
+
+    public DecoratorPatternClient(Component component) {
+        this.component = component;
+    }
+
+    public void execute() {
+        String result = component.operation();
+        log.info("result={}", result);
+    }
+}

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/code/MessageDecorator.java

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+package com.example.proxy.pureproxy.decorator.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class MessageDecorator implements Component {
+
+    private final Component component;
+
+    public MessageDecorator(Component component) {
+        this.component = component;
+    }
+
+    @Override
+    public String operation() {
+        log.info("MessageDecorator 실행!");
+
+        String result = component.operation();
+        String decoResult = "*****" + result + "*****";
+        log.info("MessageDecorator 적용 전={}, 적용 후={}", result, decoResult);
+        return decoResult;
+    }
+}

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/code/RealComponent.java

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+package com.example.proxy.pureproxy.decorator.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class RealComponent implements Component {
+    @Override
+    public String operation() {
+        log.info("RealComponent 실행!");
+        return "data";
+    }
+}

spring-core/proxy/src/test/java/com/example/proxy/pureproxy/decorator/code/TimeDecorator.java

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+package com.example.proxy.pureproxy.decorator.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class TimeDecorator implements Component {
+
+    private final Component component;
+
+    public TimeDecorator(Component component) {
+        this.component = component;
+    }
+
+    @Override
+    public String operation() {
+        log.info("TimeDecorator 실행!");
+        long startTime = System.currentTimeMillis();
+        String result = component.operation();
+        long endTime = System.currentTimeMillis();
+        long resultTime = endTime - startTime;
+        log.info("TimeDecorator 종료 resultTime={}", resultTime);
+        return result;
+    }
+}