Interface/1

.gitignore

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+/out

License

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+MIT License
+
+Copyright (c) 2023 Nimesh_Piyumantha
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

_01_Open-Close-Principle/src/BankAppWithdrawalService.java

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+import service.Account;
+
+/**
+ * @author : Nimesh Piyumantha
+ * @since : 0.1.0
+ **/
+public class BankAppWithdrawalService {
+   /* public void depositToSavingsAccount(double amount){
+        System.out.println(amount + " Deposited to your Savings Account.!");
+    }
+
+    public void depositToCurrentAccount(double amount){
+        System.out.println(amount + " Deposited to your Current Account.!");
+    }
+
+    public void withdrawFromSavingsAccount(double amount){
+        System.out.println(amount + " Withdrawn from your Savings Account.!");
+    }
+
+    public void withdrawFromCurrentAccount(double amount){
+        System.out.println(amount + " Withdrawn from your Current Account.!");
+    }
+
+    *//* I want to implement another feature for Banking App Withdrawal Service*//*
+
+    public void depositToSalarySaverAccount(double amount){
+        System.out.println(amount + " Deposited to your Salary Server Account.!");
+    }
+
+    public void withdrawFromSalarySaverAccount(double amount){
+        System.out.println(amount + " Withdrawn from your Salary Server Account.!");
+    }
+
+    *//* So here for adding a new feature I had to modify the class *//*
+    *//* So, unfortunately we have violated the Open / Close principle *//*
+    *//* Why.? *//*
+    *//* In Open/Close principle a class should be closed for modifications but opened for extensions *//*
+    *//* But here we did modifications rather than doing extensions *//*
+    *//* S0, we violate the rule */
+
+    Account account;
+
+    public BankAppWithdrawalService(Account account) {
+        this.account = account;
+    }
+
+    public void depositToAccount(double amount){
+        account.deposit(amount);
+    }
+    public void withdrawFromAccount(double amount){
+        account.withdraw(amount);
+    }
+
+    /* Now what..? */
+    /* Now if there were thousands of account types in the future, no matter */
+    /* It can be used through the Account Class */
+    /* Then this class should not be modified (Closed for modifications), but this class is open for extensions */
+}

_01_Open-Close-Principle/src/Main.java

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+import service.Account;
+import service.types.CurrentAccount;
+import service.types.SalarySaverAccount;
+import service.types.SavingAccount;
+
 /**
  * @author : Nimesh Piyumantha
  * @since : 0.1.0
  **/
 public class Main {
+    /*SOLID*/
+    /* O - Open / Close Principle */
+    /*
+     *This principle states that the software entities should be open for extensions but close
+     * for modifications
+     * */
     public static void main(String[] args) {
-        System.out.println("Hello world!");
+
+        /*BankAppWithdrawalService bankAppWithdrawalService = new BankAppWithdrawalService();
+
+        bankAppWithdrawalService.depositToCurrentAccount(100000);
+        bankAppWithdrawalService.withdrawFromCurrentAccount(5000);
+
+        bankAppWithdrawalService.depositToSalarySaverAccount(200000);
+        bankAppWithdrawalService.withdrawFromSalarySaverAccount(100000);*/
+
+
+
+        /* Let's deposit for Savings Account Bank App Withdrawal Service */
+        Account savingAccount= new SavingAccount();
+        BankAppWithdrawalService bankAppWithdrawalService1 = new BankAppWithdrawalService(savingAccount);
+        bankAppWithdrawalService1.depositToAccount(100000);
+        bankAppWithdrawalService1.depositToAccount(40000);
+
+
+        Account currentAccount= new CurrentAccount();
+        BankAppWithdrawalService bankAppWithdrawalService2 = new BankAppWithdrawalService(currentAccount);
+        bankAppWithdrawalService2.depositToAccount(200000);
+        bankAppWithdrawalService2.depositToAccount(30000);
+
+
+        Account salaryServer= new SalarySaverAccount();
+        BankAppWithdrawalService bankAppWithdrawalService3 = new BankAppWithdrawalService(salaryServer);
+        bankAppWithdrawalService3.depositToAccount(500000);
+        bankAppWithdrawalService3.depositToAccount(100000);
+
+        /* This is what we called as Open / Close Principle */
     }
-}
+}

_01_Open-Close-Principle/src/service/Account.java

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+package service;
+
+/**
+ * @author : Nimesh Piyumantha
+ * @since : 0.1.0
+ **/
+public abstract class Account {
+    /* Extract the basic services and place them here */
+    /* Make it abstract because there is nothing to implement here */
+    public abstract void deposit(double amount);
+    public abstract void withdraw(double amount);
+}

_01_Open-Close-Principle/src/service/types/CurrentAccount.java

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+package service.types;
+
+import service.Account;
+
+/**
+ * @author : Nimesh Piyumantha
+ * @since : 0.1.0
+ **/
+public class CurrentAccount extends Account {
+    @Override
+    public void deposit(double amount) {
+        System.out.println(amount + " Deposited to your Current Account.!");
+    }
+
+    @Override
+    public void withdraw(double amount) {
+        System.out.println(amount + " Withdrawn from your Current Account.!");
+    }
+}

_01_Open-Close-Principle/src/service/types/SalarySaverAccount.java

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+package service.types;
+
+import service.Account;
+
+/**
+ * @author : Nimesh Piyumantha
+ * @since : 0.1.0
+ **/
+public class SalarySaverAccount extends Account {
+    @Override
+    public void deposit(double amount) {
+        System.out.println(amount + " Deposited to your Salary Saver Account.!");
+    }
+
+    @Override
+    public void withdraw(double amount) {
+        System.out.println(amount + " Withdrawn from Salary Saver Account.!");
+    }
+}

_01_Open-Close-Principle/src/service/types/SavingAccount.java

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+package service.types;
+
+import service.Account;
+
+/**
+ * @author : Nimesh Piyumantha
+ * @since : 0.1.0
+ **/
+public class SavingAccount extends Account {
+    @Override
+    public void deposit(double amount) {
+        System.out.println(amount + " Deposited to your Savings Account.!");
+    }
+
+    @Override
+    public void withdraw(double amount) {
+        System.out.println(amount + " Withdrawn from your Savings Account.!");
+    }
+}

_02_Liskov-Substitution-Principle/_02_Liskov-Substitution-Principle.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>