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+openapi: 3.0.1
+info:
+  title: Employees Management Micro-Service
+  description: "\n## Overview\n\nEmployees Management Service API manages the employees\
+    \ of HighTec Gmbh including their qualifications. It offers the possibility to\
+    \ create, read, update and delete employees and qualifications. Existing employees\
+    \ can be assigned new qualifications or have them withdrawn. \nThe API is organized\
+    \ around REST. It has predictable resource-oriented URLs, accepts JSON-encoded\
+    \ request bodies, returns JSON-encoded responses, uses standard HTTP response\
+    \ codes and authentication.\n\n## Authentication\n\nEmployees Management Service\
+    \ API uses JWTs to authenticate requests. You will receive a bearer token by making\
+    \ a POST-Request in IntelliJ on:\n\n\n```\nPOST http://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token\n\
+    Content-Type: application/x-www-form-urlencoded\ngrant_type=password&client_id=employee-management-service&username=user&password=test\n\
+    ```\n\n\nor by CURL\n```\ncurl -X POST 'http://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token'\n\
+    --header 'Content-Type: application/x-www-form-urlencoded'\n--data-urlencode 'grant_type=password'\n\
+    --data-urlencode 'client_id=employee-management-service'\n--data-urlencode 'username=user'\n\
+    --data-urlencode 'password=test'\n```\n\nTo get a bearer-token in Postman, you\
+    \ have to follow the instructions in \n [Postman-Documentation](https://documenter.getpostman.com/view/7294517/SzmfZHnd).\n\
+    \nAll API requests must be made over HTTPS. Calls made over plain HTTP will fail.\
+    \ API requests without authentication will also fail. Each request has the URL\
+    \ \n `https://employee.szut.dev` and the address of the desired resource."
+  version: 1.0.1
+servers:
+- url: ""
+security:
+- bearerAuth: []
+paths:
+  /qualifications/{id}:
+    put:
+      tags:
+      - qualification-controller
+      summary: updates a qualification
+      operationId: updateQualification
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/QualificationPostDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "400":
+          description: invalid JSON posted
+        "200":
+          description: updated qualification
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/QualificationPostDTO'
+        "404":
+          description: resource not found
+    delete:
+      tags:
+      - qualification-controller
+      summary: deletes a qualification by id
+      operationId: deleteQualificationByDesignation
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "401":
+          description: not authorized
+        "403":
+          description: qualification is in use
+        "204":
+          description: delete successful
+        "404":
+          description: resource not found
+  /employees/{id}:
+    get:
+      tags:
+      - employee-controller
+      summary: find employee by id
+      operationId: findById
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: employee
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeResponseDTO'
+        "404":
+          description: resource not found
+    put:
+      tags:
+      - employee-controller
+      summary: updates employee by id - only changes the fields that are posted
+      operationId: updateEmployee
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/EmployeeRequestPutDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: employee
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeResponseDTO'
+        "404":
+          description: resource not found
+    delete:
+      tags:
+      - employee-controller
+      summary: deletes a employee by id
+      operationId: deleteCustomer
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "401":
+          description: not authorized
+        "204":
+          description: delete successful
+        "404":
+          description: resource not found
+  /qualifications:
+    get:
+      tags:
+      - qualification-controller
+      summary: delivers a list of all available qualifications
+      operationId: findAll
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: list of qualifications
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/QualificationPostDTO'
+    post:
+      tags:
+      - qualification-controller
+      summary: creates a new qualification with its id and designation
+      operationId: createQualification
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/QualificationPostDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "201":
+          description: created qualification
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/QualificationPostDTO'
+        "400":
+          description: invalid JSON posted
+  /employees:
+    get:
+      tags:
+      - employee-controller
+      summary: delivers a list of all employees
+      operationId: findAll_1
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: list of employees
+          content:
+            application/json:
+              schema:
+                type: array
+                items: 
+                  $ref: '#/components/schemas/EmployeeResponseDTO'
+    post:
+      tags:
+      - employee-controller
+      summary: creates a new employee
+      operationId: createEmployee
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/EmployeeRequestDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "400":
+          description: invalid JSON posted
+        "201":
+          description: created employee
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeResponseDTO'
+  /employees/{id}/qualifications:
+    get:
+      tags:
+      - employee-controller
+      summary: finds all qualifications of an employee by id
+      operationId: findAllQualificationOfAEmployeeById
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: employee with a list of his qualifications
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeNameAndSkillDataDTO'
+        "404":
+          description: resource not found
+    post:
+      tags:
+      - employee-controller
+      summary: adds a qualification to an employee by id
+      operationId: addQualificationToEmployeeById
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/QualificationPostDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "400":
+          description: invalid JSON posted or employee already has this qualification
+        "200":
+          description: employee with a list of his qualifications
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeNameAndSkillDataDTO'
+        "404":
+          description: resource not found
+    delete:
+      tags:
+      - employee-controller
+      summary: deletes a qualification of an employee by id
+      operationId: removeQualificationFromEmployee
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/QualificationPostDTO'
+        required: true
+      responses:
+        "401":
+          description: not authorized
+        "200":
+          description: employee with a list of his qualifications
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeeNameAndSkillDataDTO'
+        "404":
+          description: resource not found
+  /qualifications/{id}/employees:
+    get:
+      tags:
+      - qualification-controller
+      summary: find employees by qualification id
+      operationId: findAllEmployeesByQualification
+      parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: integer
+          format: int64
+      responses:
+        "200":
+          description: List of employees who have the desired qualification
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/EmployeesForAQualificationDTO'
+        "401":
+          description: not authorized
+        "404":
+          description: qualification id does not exist
+components:
+  schemas:
+    QualificationPostDTO:
+      required:
+      - skill
+      type: object
+      properties:
+        skill:
+          type: string
+    EmployeeRequestPutDTO:
+      type: object
+      properties:
+        lastName:
+          type: string
+        firstName:
+          type: string
+        street:
+          type: string
+        postcode:
+          type: string
+        city:
+          type: string
+        phone:
+          type: string
+        skillSet:
+          type: array
+          items:
+            type: integer
+            format: int64
+    EmployeeResponseDTO:
+      required:
+      - city
+      - firstName
+      - lastName
+      - phone
+      - postcode
+      - street
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        lastName:
+          type: string
+        firstName:
+          type: string
+        street:
+          type: string
+        postcode:
+          maxLength: 5
+          minLength: 5
+          type: string
+        city:
+          type: string
+        phone:
+          type: string
+        skillSet:
+          type: array
+          items:
+            $ref: '#/components/schemas/QualificationGetDTO'
+    QualificationGetDTO:
+      type: object
+      properties:
+        skill:
+          type: string
+        id:
+          type: integer
+          format: int64
+    EmployeeRequestDTO:
+      required:
+      - city
+      - firstName
+      - lastName
+      - phone
+      - postcode
+      - street
+      type: object
+      properties:
+        lastName:
+          type: string
+        firstName:
+          type: string
+        street:
+          type: string
+        postcode:
+          maxLength: 5
+          minLength: 5
+          type: string
+        city:
+          type: string
+        phone:
+          type: string
+        skillSet:
+          type: array
+          items:
+            type: integer
+            format: int64
+    EmployeeNameAndSkillDataDTO:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        lastName:
+          type: string
+        firstName:
+          type: string
+        skillSet:
+          uniqueItems: true
+          type: array
+          items:
+            $ref: '#/components/schemas/QualificationPostDTO'
+    EmployeeNameDataDTO:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        lastName:
+          type: string
+        firstName:
+          type: string
+    EmployeesForAQualificationDTO:
+      type: object
+      properties:
+        qualification:
+          $ref: '#/components/schemas/QualificationGetDTO'
+        employees:
+          uniqueItems: true
+          type: array
+          items:
+            $ref: '#/components/schemas/EmployeeNameDataDTO'
+  securitySchemes:
+    bearerAuth:
+      type: http
+      scheme: bearer
+      bearerFormat: JWT