added lab13 ex2

src/lab13_proxy/ex2/Account.java

@@ -0,0 +1,36 @@
+package lab13_proxy.ex2;
+
+import java.util.Random;
+
+public class Account {
+    private int balance;
+    private int accountNumber;
+    private String owner;
+
+    public Account(String owner, int startBalance) {
+        this.owner = owner;
+        this.balance = startBalance;
+        this.accountNumber = new Random().hashCode();
+    }
+
+    public void deposit(int amount) {
+        balance += amount;
+    }
+
+    public void withdraw(int amount) {
+        balance -= amount;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public int getBalance() {
+        return balance;
+    }
+
+    @Override
+    public String toString() {
+        return "account " + this.accountNumber + " belonging to " + this.owner;
+    }
+}

src/lab13_proxy/ex2/Bank.java

@@ -0,0 +1,52 @@
+package lab13_proxy.ex2;
+
+import java.util.ArrayList;
+
+public class Bank {
+    private final ArrayList<String> blacklistedClients = new ArrayList<>();
+
+    public void blacklist(String client) {
+        blacklistedClients.add(client);
+    }
+    public boolean isBlacklisted(String client) {
+        return blacklistedClients.contains(client);
+    }
+
+    public void deposit(String client, Account account, int amount) {
+        if (amount < 0) {
+            System.out.println("Cannot deposit a negative amount");
+            return;
+        }
+        if (isBlacklisted(client)) {
+            System.out.println(client + " is on a blacklist and does not have the right to DEPOSIT money into " + account);
+            return;
+        }
+
+        account.deposit(amount);
+        System.out.println(client + " has deposited " + amount + " on " + account + ". New balance is " + account.getBalance());
+    }
+
+    public void withdraw(String client, Account account, int amount) {
+        if (amount < 0) {
+            System.out.println("Cannot withdraw a negative amount");
+            return;
+        }
+        if (isBlacklisted(client)) {
+            System.out.println(client + " is on a blacklist and does not have the right to WITHDRAW money from " + account);
+            return;
+        }
+
+        if (!account.getOwner().equals(client)) {
+            System.out.println(client + " cannot WITHDRAW money from " + account + " because they are not the owner");
+            return;
+        }
+
+        if (account.getBalance() < amount) {
+            System.out.println(client + " cannot WITHDRAW money from " + account + " because there is not enough money on the account.");
+            return;
+        }
+
+        account.withdraw(amount);
+        System.out.println(client + " has withdrawn " + amount + " from " + account + ". New balance is " + account.getBalance());
+    }
+}

src/lab13_proxy/ex2/Main.java

@@ -0,0 +1,18 @@
+package lab13_proxy.ex2;
+
+public class Main {
+    public static void main(String[] args) {
+        Account account = new Account("Pascale", 16000);
+
+        Bank bank = new Bank();
+        bank.blacklist("Jean");
+        bank.blacklist("Pierre");
+
+        bank.deposit("Marcel", account, 1000);
+        bank.deposit("Jean", account, 1000);
+        bank.withdraw("Marcel", account, 1000);
+        bank.withdraw("Pascale", account, 1000000);
+        bank.withdraw("Pascale", account, 1000);
+        bank.withdraw("Pierre", account, 1000);
+    }
+}