feat: created abstract class 'BankAccount' that uses all base methods of 'CheckingAccount'; created 'SavingsAccount' class that is extended from 'BankAccount'; changed 'CheckingAccount' to be an extension of 'BankAccount';

Author: “A1-4U2T1NN”

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAccount.java

@@ -0,0 +1,103 @@
+package com.codedifferently.lesson17.bank;
+
+import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
+import java.util.Set;
+
+public abstract class BankAccount {
+  protected  final Set<Customer> owners;
+  protected final String accountNumber;
+  protected double balance;
+  protected boolean isActive;
+
+  /**
+   * Creates a new checking account.
+   *
+   * @param accountNumber The account number.
+   * @param owners The owners of the account.
+   * @param initialBalance The initial balance of the account.
+   */
+  public BankAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
+    this.accountNumber = accountNumber;
+    this.owners = owners;
+    this.balance = initialBalance;
+    isActive = true;
+  }
+
+  /**
+   * Gets the account number.
+   *
+   * @return The account number.
+   */
+  public String getAccountNumber() {
+    return accountNumber;
+  }
+
+  /**
+   * Gets the owners of the account.
+   *
+   * @return The owners of the account.
+   */
+  public Set<Customer> getOwners() {
+    return owners;
+  }
+
+  /**
+   * Deposits funds into the account.
+   *
+   * @param amount The amount to deposit.
+   */
+  public void deposit(double amount) throws IllegalStateException {
+    if (isClosed()) {
+      throw new IllegalStateException("Cannot deposit to a closed account");
+    }
+    if (amount <= 0) {
+      throw new IllegalArgumentException("Deposit amount must be positive");
+    }
+    balance += amount;
+  }
+
+  /**
+   * Withdraws funds from the account.
+   *
+   * @param amount
+   * @throws InsufficientFundsException
+   */
+  public void withdraw(double amount) throws InsufficientFundsException {
+    if (isClosed()) {
+      throw new IllegalStateException("Cannot withdraw from a closed account");
+    }
+    if (amount <= 0) {
+      throw new IllegalStateException("Withdrawal amount must be positive");
+    }
+    if (balance < amount) {
+      throw new InsufficientFundsException("Account does not have enough funds for withdrawal");
+    }
+    balance -= amount;
+  }
+
+  /**
+   * Gets the balance of the account.
+   *
+   * @return The balance of the account.
+   */
+  public double getBalance() {
+    return balance;
+  }
+
+  /** Closes the account. */
+  public void closeAccount() throws IllegalStateException {
+    if (balance > 0) {
+      throw new IllegalStateException("Cannot close account with a positive balance");
+    }
+    isActive = false;
+  }
+
+  /**
+   * Checks if the account is closed.
+   *
+   * @return True if the account is closed, otherwise false.
+   */
+  public boolean isClosed() {
+    return !isActive;
+  }
+}

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java

@@ -1,15 +1,9 @@
 package com.codedifferently.lesson17.bank;
 
-import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
 import java.util.Set;
 
 /** Represents a checking account. */
-public class CheckingAccount {
-
-  private final Set<Customer> owners;
-  private final String accountNumber;
-  private double balance;
-  private boolean isActive;
+public class CheckingAccount extends BankAccount{
 
   /**
    * Creates a new checking account.
@@ -19,88 +13,7 @@ public class CheckingAccount {
    * @param initialBalance The initial balance of the account.
    */
   public CheckingAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
-    this.accountNumber = accountNumber;
-    this.owners = owners;
-    this.balance = initialBalance;
-    isActive = true;
-  }
-
-  /**
-   * Gets the account number.
-   *
-   * @return The account number.
-   */
-  public String getAccountNumber() {
-    return accountNumber;
-  }
-
-  /**
-   * Gets the owners of the account.
-   *
-   * @return The owners of the account.
-   */
-  public Set<Customer> getOwners() {
-    return owners;
-  }
-
-  /**
-   * Deposits funds into the account.
-   *
-   * @param amount The amount to deposit.
-   */
-  public void deposit(double amount) throws IllegalStateException {
-    if (isClosed()) {
-      throw new IllegalStateException("Cannot deposit to a closed account");
-    }
-    if (amount <= 0) {
-      throw new IllegalArgumentException("Deposit amount must be positive");
-    }
-    balance += amount;
-  }
-
-  /**
-   * Withdraws funds from the account.
-   *
-   * @param amount
-   * @throws InsufficientFundsException
-   */
-  public void withdraw(double amount) throws InsufficientFundsException {
-    if (isClosed()) {
-      throw new IllegalStateException("Cannot withdraw from a closed account");
-    }
-    if (amount <= 0) {
-      throw new IllegalStateException("Withdrawal amount must be positive");
-    }
-    if (balance < amount) {
-      throw new InsufficientFundsException("Account does not have enough funds for withdrawal");
-    }
-    balance -= amount;
-  }
-
-  /**
-   * Gets the balance of the account.
-   *
-   * @return The balance of the account.
-   */
-  public double getBalance() {
-    return balance;
-  }
-
-  /** Closes the account. */
-  public void closeAccount() throws IllegalStateException {
-    if (balance > 0) {
-      throw new IllegalStateException("Cannot close account with a positive balance");
-    }
-    isActive = false;
-  }
-
-  /**
-   * Checks if the account is closed.
-   *
-   * @return True if the account is closed, otherwise false.
-   */
-  public boolean isClosed() {
-    return !isActive;
+    super(accountNumber, owners, initialBalance);
   }
 
   @Override

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java

@@ -0,0 +1,44 @@
+package com.codedifferently.lesson17.bank;
+
+import java.util.Set;
+
+/** Represents a checking account. */
+public class SavingsAccount extends BankAccount{
+
+  /**
+   * Creates a new checking account.
+   *
+   * @param accountNumber The account number.
+   * @param owners The owners of the account.
+   * @param initialBalance The initial balance of the account.
+   */
+  public SavingsAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
+    super(accountNumber, owners, initialBalance);
+  }
+
+  @Override
+  public int hashCode() {
+    return accountNumber.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj instanceof CheckingAccount other) {
+      return accountNumber.equals(other.accountNumber);
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return "CheckingAccount{"
+        + "accountNumber='"
+        + accountNumber
+        + '\''
+        + ", balance="
+        + balance
+        + ", isActive="
+        + isActive
+        + '}';
+  }
+}