feat : Design Pattern - 프록시(Proxy) 패턴 구현

놀이터(예제 코드 작성)/solid-design-pattern-sample/README.md

@@ -95,6 +95,12 @@
 
 ### 프록시(Proxy) 패턴
 
+#### 구현 요구사항
+
+- 지갑의 주인은 지갑에 대해 입금 또는 출금을 진행할 수 있다.
+- 지갑의 동작은 입금 및 출금만 가능하도록 제한된다. 
+- 지갑에 대해 입금 또는 출금이 이루어질 때 메시지를 출력한다.
+
 ### 어댑터(Adapter) 패턴
 
 ### 옵저버(Observer) 패턴

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/ExtendsProxyWallet.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+class ExtendsProxyWallet(balance: Int) : RealWallet(balance) {
+    override fun deposit(amount: Int) {
+        println("지갑에 $amount 원이 입금되었습니다.")
+        super.deposit(amount)
+    }
+
+    override fun withdrawal(amount: Int) {
+        println("지갑에서 $amount 원이 출금되었습니다.")
+        super.withdrawal(amount)
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/ImplementsProxyWallet.kt

@@ -0,0 +1,15 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+class ImplementsProxyWallet(
+    private val realWallet: RealWallet
+) : Wallet {
+    override fun deposit(amount: Int) {
+        println("지갑에 $amount 원이 입금되었습니다.")
+        realWallet.deposit(amount)
+    }
+
+    override fun withdrawal(amount: Int) {
+        println("지갑에서 $amount 원이 출금되었습니다.")
+        realWallet.withdrawal(amount)
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/Owner.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+class Owner(
+    private val wallet: Wallet
+) {
+    fun deposit(amount: Int) {
+        wallet.deposit(amount)
+    }
+
+    fun withdrawal(amount: Int) {
+        wallet.withdrawal(amount)
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/RealWallet.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+open class RealWallet(
+    private var balance: Int = 0
+) : Wallet {
+    override fun deposit(amount: Int) {
+        this.balance += amount
+    }
+
+    override fun withdrawal(amount: Int) {
+        this.balance -= amount
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/Wallet.kt

@@ -0,0 +1,7 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+interface Wallet {
+    fun deposit(amount: Int)
+
+    fun withdrawal(amount: Int)
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/after/WalletApplication.kt

@@ -0,0 +1,9 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.after
+
+class ProxyWalletApplication
+
+fun main() {
+    val wallet = ImplementsProxyWallet(RealWallet())
+    val owner = Owner(wallet)
+    owner.deposit(1000)
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/before/Owner.kt

@@ -0,0 +1,13 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.before
+
+class Owner(
+    private val wallet: Wallet
+) {
+    fun deposit(amount: Int) {
+        wallet.deposit(amount)
+    }
+
+    fun withdrawal(amount: Int) {
+        wallet.withdrawal(amount)
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/before/Wallet.kt

@@ -0,0 +1,15 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.before
+
+class Wallet(
+    private var balance: Int = 0
+) {
+    fun deposit(amount: Int) {
+        println("지갑에 $amount 원이 입금되었습니다.")
+        this.balance += amount
+    }
+
+    fun withdrawal(amount: Int) {
+        println("지갑에서 $amount 원이 출금되었습니다.")
+        this.balance -= amount
+    }
+}

놀이터(예제 코드 작성)/solid-design-pattern-sample/src/main/kotlin/com/banjjoknim/soliddesignpatternsample/designpattern/proxy/before/WalletApplication.kt

@@ -0,0 +1,9 @@
+package com.banjjoknim.soliddesignpatternsample.designpattern.proxy.before
+
+class WalletApplication
+
+fun main() {
+    val wallet = Wallet()
+    val owner = Owner(wallet)
+    owner.deposit(1000)
+}