Screen Test Assignment

A Spring Boot 3.5.5 + Java 17 based assignment project implementing two REST API tasks with proper layered architecture, validation, exception handling, H2 database integration, testing, and a modern interactive preview dashboard.

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Tech Stack

• Java 17
• Spring Boot 3.5.5
• Spring Web
• Spring Data JPA
• H2 Database
• Maven
• JUnit 5
• Mockito
• MockMvc
• Lombok

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Features

Task 1: Text Replacement API

Implements text transformation rules based on input length.

Task 2: Forecast API

Fetches live weather data from Open-Meteo API, extracts maximum values, stores results in database, and returns structured responses.

Additional Features

• Global exception handling
• Request validation
• H2 in-memory database
• Automated test cases
• Interactive modern UI dashboard for API preview
• Copy API response support
• Responsive frontend preview

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Project Structure

src/
├── main/
│   ├── java/com/example/screen_test/
│   │   ├── config/
│   │   │   └── AppConfig.java
│   │   │
│   │   ├── controller/
│   │   │   ├── ForecastController.java
│   │   │   └── TextReplaceController.java
│   │   │
│   │   ├── dto/
│   │   │   ├── ForecastRequest.java
│   │   │   ├── ForecastResponse.java
│   │   │   ├── ErrorResponse.java
│   │   │   └── OpenMeteoResponse.java
│   │   │
│   │   ├── entity/
│   │   │   └── ForecastRecord.java
│   │   │
│   │   ├── exception/
│   │   │   ├── GlobalExceptionHandler.java
│   │   │   └── UpstreamApiException.java
│   │   │
│   │   ├── repository/
│   │   │   └── ForecastRepository.java
│   │   │
│   │   ├── service/
│   │   │   ├── ForecastService.java
│   │   │   └── TextReplaceService.java
│   │   │
│   │   └── ScreenTestApplication.java
│   │
│   └── resources/
│       ├── application.properties
│       └── static/
│           └── index.html
│
└── test/
    └── java/com/example/screen_test/
        ├── controller/
        │   ├── ForecastControllerTest.java
        │   └── TextReplaceControllerTest.java
        │
        ├── service/
        │   └── ForecastServiceTest.java
        │
        ├── integration/
        │   └── ForecastIntegrationTest.java
        │
        └── ScreenTestApplicationTests.java

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Task 1: Text Replacement API

Endpoint

GET /api/v1/replace?text=value

Rules

• If input length < 2 → 400 Bad Request
• If input length = 2 → 200 OK with empty response
• If input length > 2:
  • first character becomes *
  • last character becomes $

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Examples

Request

GET /api/v1/replace?text=elephant

Response:

*lephan$

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Request

GET /api/v1/replace?text=abc

Response:

*b$

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Request

GET /api/v1/replace?text=hi

Response:

(empty body)

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Request

GET /api/v1/replace?text=a

Response:

{
  "timestamp": "...",
  "status": 400,
  "error": "Bad Request",
  "message": "Text must contain at least 2 characters",
  "path": "/api/v1/replace"
}

---

Task 2: Forecast API

Endpoint

POST /api/v1/forcast

Request Body

{
  "addTemprature": true,
  "addHumidity": true,
  "addWindSpeed": true
}

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Functionality

This API:

• Calls external Open-Meteo weather API
• Fetches live weather forecast
• Extracts:
  • maximum temperature
  • maximum humidity
  • maximum wind speed
• Stores extracted values in H2 database
• Returns structured API response

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External API Used

https://api.open-meteo.com/v1/forecast

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Success Response

{
  "maxTemperature": 31.7,
  "maxHumidity": 89.0,
  "maxWindSpeed": 15.6,
  "message": "Forecast saved successfully"
}

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Error Responses

Missing Request Fields

{
  "status": 400,
  "error": "Bad Request",
  "message": "All request body parameters are mandatory"
}

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Upstream API Failure

{
  "status": 502,
  "error": "Upstream API Unreachable",
  "message": "Connection to the upstream is unreachable"
}

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Internal Server Error

{
  "status": 500,
  "error": "Internal Server Error",
  "message": "Something went wrong"
}

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H2 Database

Console

Open:

http://localhost:8080/h2-console

Credentials:

JDBC URL: jdbc:h2:mem:forecastdb
Username: sa
Password: (leave empty)

Run query:

SELECT * FROM FORECAST_RECORDS;

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Interactive Dashboard Preview

A modern UI dashboard is included for testing both APIs directly from browser.

Open:

http://localhost:8080

Features:

• Task 1 live testing
• Task 2 live testing
• response viewer
• loading indicators
• copy response button
• responsive modern UI

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Running the Project

Clone

git clone <your-repo-url>
cd screen-test

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Build

mvn clean install

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Run

mvn spring-boot:run

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Run Tests

mvn test

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Test Coverage

Includes:

• Controller tests
• Service tests
• Integration tests
• Validation scenarios
• Positive test cases
• Negative test cases
• Edge cases

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Author

Sarthak Singh