spring core proxy : proxy pattern

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

@@ -0,0 +1,28 @@
+package com.example.proxy.pureproxy.proxy;
+
+import com.example.proxy.pureproxy.proxy.code.CacheProxy;
+import com.example.proxy.pureproxy.proxy.code.ProxyPatternClient;
+import com.example.proxy.pureproxy.proxy.code.RealSubject;
+import org.junit.jupiter.api.Test;
+
+public class ProxyPatternTest {
+
+    @Test
+    void noProxyTest() {
+        RealSubject realSubject = new RealSubject();
+        ProxyPatternClient client = new ProxyPatternClient(realSubject);
+        client.execute();
+        client.execute();
+        client.execute();
+    }
+
+    @Test
+    void cacheProxyTest() {
+        RealSubject realSubject = new RealSubject();
+        CacheProxy cacheProxy = new CacheProxy(realSubject);
+        ProxyPatternClient client = new ProxyPatternClient(cacheProxy);
+        client.execute();
+        client.execute();
+        client.execute();
+    }
+}

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

@@ -0,0 +1,23 @@
+package com.example.proxy.pureproxy.proxy.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class CacheProxy implements Subject {
+
+    private final Subject target;
+    private String cacheValue;
+
+    public CacheProxy(Subject target) {
+        this.target = target;
+    }
+
+    @Override
+    public String operation() {
+        log.info("프록시 호출!");
+        if (cacheValue == null) {
+            cacheValue = target.operation();
+        }
+        return cacheValue;
+    }
+}

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

@@ -0,0 +1,14 @@
+package com.example.proxy.pureproxy.proxy.code;
+
+public class ProxyPatternClient {
+
+    private final Subject subject;
+
+    public ProxyPatternClient(Subject subject) {
+        this.subject = subject;
+    }
+
+    public void execute() {
+        subject.operation();
+    }
+}

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

@@ -0,0 +1,21 @@
+package com.example.proxy.pureproxy.proxy.code;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class RealSubject implements Subject {
+    @Override
+    public String operation() {
+        log.info("실제 객체 호출");
+        sleep(1000);
+        return "data";
+    }
+
+    private void sleep(int millis) {
+        try {
+            Thread.sleep(millis);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}

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

@@ -0,0 +1,5 @@
+package com.example.proxy.pureproxy.proxy.code;
+
+public interface Subject {
+    String operation();
+}