add functionality code for banking server app

pom.xml

@@ -27,6 +27,21 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.30</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+            <version>6.0.11</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/com/example/flagsmithspringbootbankingapp/Account.java

@@ -0,0 +1,36 @@
+package com.example.flagsmithspringbootbankingapp;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.UUID;
+
+@Getter
+@Setter
+public class Account {
+    String id;
+    String accountHolderName;
+    double balance;
+
+    public Account(String accountHolderName) {
+        this.id = UUID.randomUUID().toString();
+        this.accountHolderName = accountHolderName;
+        this.balance = 0;
+    }
+}
+
+
+@Getter
+@Setter
+class AddMoneyRequest {
+    String accountId;
+    double amount;
+}
+
+
+@Getter
+@Setter
+class WithdrawMoneyRequest {
+    String accountId;
+    double amount;
+}

src/main/java/com/example/flagsmithspringbootbankingapp/AccountService.java

@@ -0,0 +1,39 @@
+package com.example.flagsmithspringbootbankingapp;
+
+import java.util.HashMap;
+
+public class AccountService {
+
+    private final HashMap<String, Account> UserAccounts;
+
+    // initialises empty map to store user's accounts info
+    public AccountService() {
+        UserAccounts = new HashMap<>();
+    }
+
+    // get account via accountID
+    public Account GetAccount(String accountID)  {
+        return this.UserAccounts.get(accountID);
+    }
+
+    // create a new account and add it to the map
+    public Account CreateAccount(String accountHolderName) {
+        Account newAccount = new Account(accountHolderName);
+        this.UserAccounts.put(newAccount.getId(), newAccount);
+        return newAccount;
+    }
+
+    // add money to user's bank account
+    public Account AddMoney(String accountId, double amount) {
+        Account acc = this.GetAccount(accountId);
+        acc.balance += amount;
+        return acc;
+    }
+
+    // withdraw money from user's bank account
+    public Account WithdrawMoney(String accountId, double amount) {
+        Account acc = this.GetAccount(accountId);
+        acc.balance += amount;
+        return acc;
+    }
+}

src/main/java/com/example/flagsmithspringbootbankingapp/FlagsmithSpringBootBankingAppApplication.java

@@ -1,13 +1,54 @@
 package com.example.flagsmithspringbootbankingapp;
 
+
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
 
 @SpringBootApplication
+@RestController
 public class FlagsmithSpringBootBankingAppApplication {
-
+    private static AccountService accountService;
     public static void main(String[] args) {
+        accountService = new AccountService();
         SpringApplication.run(FlagsmithSpringBootBankingAppApplication.class, args);
     }
 
+    // endpoint to create a new account
+    @PostMapping(path = "/create-account", consumes = MediaType.APPLICATION_JSON_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<Account> createAccount(@RequestBody String accountHolderName) {
+        return ResponseEntity.ok(accountService.CreateAccount(accountHolderName));
+    }
+
+    // endpoint to add money to an account
+    @PostMapping(path = "/add-money", consumes = MediaType.APPLICATION_JSON_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public Account addMoney(@RequestBody AddMoneyRequest req) {
+        return accountService.AddMoney(req.accountId, req.amount);
+    }
+
+    // endpoint to withdraw money from an account
+    @PostMapping(path = "/withdraw-money", consumes = MediaType.APPLICATION_JSON_VALUE,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<Account> withdrawMoney(@RequestBody WithdrawMoneyRequest req) {
+        return ResponseEntity.ok(accountService.WithdrawMoney(req.accountId, req.amount));
+
+    }
+
+    // endpoint to check account balance
+    @GetMapping("/check-balance")
+    public double checkBalance(@RequestParam(value = "accountId") String accountId) {
+        Account account = accountService.GetAccount(accountId);
+        return account.balance;
+    }
+
+    // endpoint to get the current interest rate
+    @GetMapping("/interest-rate")
+    public ResponseEntity<Object> getInterestRate() {
+        return ResponseEntity.ok(3.5);
+    }
 }
+