code manipulation : dynamic proxy(proxy pattern)

code-manipulation/dynamic-proxy/pom.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.example</groupId>
+  <artifactId>dynamic-proxy</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>dynamic-proxy</name>
+  <!-- FIXME change it to the project's website -->
+  <url>http://www.example.com</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>11</maven.compiler.source>
+    <maven.compiler.target>11</maven.compiler.target>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+</project>

code-manipulation/dynamic-proxy/src/main/java/org/example/proxy/Book.java

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+package org.example.proxy;
+
+public class Book {
+
+    private Integer id;
+
+    private String title;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+}

code-manipulation/dynamic-proxy/src/main/java/org/example/proxy/BookService.java

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+package org.example.proxy;
+
+public interface BookService {
+
+    void rent(Book book);
+}

code-manipulation/dynamic-proxy/src/main/java/org/example/proxy/BookServiceProxy.java

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+package org.example.proxy;
+
+public class BookServiceProxy implements BookService {
+
+    BookService bookService;
+
+    public BookServiceProxy(BookService bookService) {
+        this.bookService = bookService;
+    }
+
+    @Override
+    public void rent(Book book) {
+        System.out.println("로깅!!");
+        bookService.rent(book);
+        System.out.println("다른기능!!");
+    }
+}

code-manipulation/dynamic-proxy/src/main/java/org/example/proxy/DefaultBookService.java

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+package org.example.proxy;
+
+public class DefaultBookService implements BookService{
+
+    @Override
+    public void rent(Book book) {
+        System.out.println("rent: " + book.getTitle());
+    }
+}

code-manipulation/dynamic-proxy/src/test/java/org/example/proxy/BookServiceTest.java

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+package org.example.proxy;
+
+import org.junit.Test;
+
+public class BookServiceTest {
+
+    BookService bookService = new BookServiceProxy(new DefaultBookService());
+
+    @Test
+    public void proxy() {
+
+        Book book = new Book();
+        book.setTitle("spring");
+
+        bookService.rent(book);
+    }
+}