adding yml file and generator

spring-boot-modules/spring-boot-swagger-2/pom.xml

@@ -112,6 +112,7 @@
                         <configuration>
                             <skipValidateSpec>true</skipValidateSpec>
                             <inputSpec>${project.basedir}/src/main/resources/static/event.yaml</inputSpec>
+                            <inputSpec>${project.basedir}/src/main/resources/static/account_api_description.yaml</inputSpec>
                             <generatorName>spring</generatorName>
                             <configOptions>
                                 <java8>true</java8>

spring-boot-modules/spring-boot-swagger-2/src/main/java/com/baeldung/apifirstdevelopment/controller/AccountController.java

@@ -0,0 +1,20 @@
+package com.baeldung.apifirstdevelopment.controller;
+
+import org.openapitools.api.AccountApi;
+import org.openapitools.model.Account;
+import org.openapitools.model.DepositRequest;
+import org.springframework.http.ResponseEntity;
+
+public class AccountController implements AccountApi {
+    @Override
+    public ResponseEntity<Void> depositToAccount(DepositRequest depositRequest) {
+        //Execute the business logic through Service/Utils/Repository classes
+        return AccountApi.super.depositToAccount(depositRequest);
+    }
+
+    @Override
+    public ResponseEntity<Account> getAccount() {
+        //Execute the business logic through Service/Utils/Repository classes
+        return AccountApi.super.getAccount();
+    }
+}

spring-boot-modules/spring-boot-swagger-2/src/main/resources/account_api_description.yaml

@@ -0,0 +1,78 @@
+openapi: 3.0.3
+info:
+  title: Banking API Specification for account interoperations
+  description: |-
+    A simple banking API that allows two operations:
+    - get account balance given account number
+    - deposit amount to a account
+  version: 1.0-SNAPSHOT
+servers:
+  - url: https://testenvironment.org/api/v1
+  - url: https://prodenvironment.org/api/v1
+tags:
+  - name: accounts
+    description: Operations for bank accounts
+
+paths:
+  /account:
+    get:
+      tags:
+        - accounts
+      summary: Get account information
+      description: Get account information using account number
+      operationId: getAccount
+      responses:
+        200:
+          description: Success
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Account'
+        404:
+          description: Account not found
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/AccountNotFoundError'
+  /account/deposit:
+    post:
+      tags:
+        - accounts
+      summary: Deposit amount to account
+      description: Initiates a deposit operation of a desired amount to the account specified
+      operationId: depositToAccount
+      requestBody:
+        description: Account number and desired amount to deposit
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/DepositRequest'
+        required: true
+      responses:
+        204:
+          description: Success
+        404:
+          description: Account not found
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/AccountNotFoundError'
+components:
+  schemas:
+    Account:
+      type: object
+      properties:
+        balance:
+          type: number
+    AccountNotFoundError:
+      type: object
+      properties:
+        message:
+          type: string
+    DepositRequest:
+      type: object
+      properties:
+        accountNumber:
+          type: string
+        depositAmount:
+          type: number