Weather Information API for Pincode

Project Overview

This is a Spring Boot REST API to fetch and store weather information for a particular day and pincode. The system:

1. Retrieves latitude and longitude for a given pincode using the OpenWeather Geocoding API.
2. Fetches weather information based on latitude and longitude using the OpenWeather API.
3. Saves the pincode's latitude, longitude, and weather information in a MySQL database for optimized subsequent calls.

Features

• Input: Pincode (e.g., 411014) and date (e.g., 2020-10-15).
• Storage:
  • Stores latitude and longitude of the pincode.
  • Caches weather information to reduce external API calls.
• Optimization:
  • If weather data for a pincode and date is already present, it fetches from the database.
  • External API calls are minimized.
• Testing: The API has been tested using Postman.
• Postman Collection Documentation: View Collection

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Prerequisites

1. Tools Required

• Java 17+
• Maven 3.6+
• MySQL 8.0+
• Postman (for testing)

2. External API Key

• Sign up on OpenWeather to get an API key.
• Add your API key in Constants class for GEOCODING_API_URL and WEATHER_API_URL.

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Setup Instructions

1. Clone the Repository

git clone <repository-url>
cd weather-information-api

2. Configure Database

• Update application.properties with your MySQL credentials:

  spring.datasource.url=jdbc:mysql://localhost:3306/weather_api_db
  spring.datasource.username=your_username
  spring.datasource.password=your_password

• Create the database manually:

  CREATE DATABASE weather_api_db;

3. Add API Keys

• Open Constants.java and update:

  public static final String GEOCODING_API_URL = "https://api.openweathermap.org/geo/1.0/zip?zip=%s,IN&appid={YOUR_API_KEY}";
  public static final String WEATHER_API_URL = "https://api.openweathermap.org/data/2.5/weather?lat=%f&lon=%f&appid={YOUR_API_KEY}";

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Build and Run

1. Build the Project

mvn clean install

2. Run the Project

mvn spring-boot:run

• The application will run on http://localhost:8080/api/v1.

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API Endpoints

1. Fetch Weather Information

• Endpoint: /weather
• Method: POST
• Description: Fetches weather data for a given pincode and date.
• Request Params:
  • pincode (String): Pincode for the location (e.g., 411014).
  • forDate (LocalDate): Date for which weather is requested (e.g., 2020-10-15).
• Sample Request:

  curl -X POST "http://localhost:8080/api/v1/weather" \
  -d "pincode=411014" \
  -d "forDate=2020-10-15"

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Database Schema

1. Location Table

Field	Type	Description
id	BIGINT (PK)	Auto-generated ID
pincode	VARCHAR(255)	Pincode
latitude	DOUBLE	Latitude
longitude	DOUBLE	Longitude

2. WeatherData Table

Field	Type	Description
id	BIGINT (PK)	Auto-generated ID
location_id	BIGINT (FK)	References Location table
forDate	DATE	Weather date
temperatureCurrent	DOUBLE	Current temperature (Celsius)
temperatureFeelsLike	DOUBLE	Feels-like temperature (Celsius)
humidity	INT	Humidity (%)
weatherInfo	JSON	Raw weather info JSON

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Testing with Postman

1. Open Postman Collection.
2. Update variables (baseURL, API key) if necessary.
3. Test the /weather endpoint with required parameters.

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Key Highlights

• Optimized Caching: Weather data is stored in the database to avoid repeated API calls.
• Error Handling: Comprehensive error handling for API failures and database issues.
• Modular Design: Service and repository layers for maintainability.

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Testing and TDD Approach

Our project incorporates JUnit for comprehensive testing and follows a Test-Driven Development (TDD) methodology to ensure code reliability, maintainability, and alignment with project requirements.

Testing Frameworks and Tools Used

• JUnit: For writing and running test cases.
• Mockito: For mocking dependencies and simulating behaviors in unit tests.
• AssertJ: For fluent and expressive assertions.
• H2 Database: For in-memory integration testing with a clean, isolated database state.

Key Test Categories

1. Unit Tests:

   • Focused on individual components like services and repositories.
   • Mocked external dependencies using Mockito to test isolated logic.
   • Example: WeatherServiceImplTest verifies weather data retrieval with and without cached data.

2. Integration Tests:

   • Validated end-to-end functionality of components interacting with each other.
   • Used the H2 in-memory database to simulate real database behavior.
   • Example: LocationRepositoryTest and WeatherDataRepositoryTest test CRUD operations and custom queries.

3. Test Coverage:

   • Comprehensive coverage of all major components.
   • Assured validation logic, database interactions, and service flows are functioning as expected.

A Maven project structure with the appropriate placement of test files: src ├── main │ ├── java │ │ └── com │ │ └── example │ │ ├── controller │ │ ├── service │ │ ├── repository │ │ ├── model │ │ └── config │ └── resources │ └── application.properties │
└── test └── java └── com └── example ├── service │ └── WeatherServiceImplTest.java └── repository ├── LocationRepositoryTest.java └── WeatherDataRepositoryTest.java

Configuration for Testing

• The application.properties file ensures isolated testing with in-memory or dedicated test databases:

  spring.datasource.url=jdbc:h2:mem:testdb
  spring.jpa.hibernate.ddl-auto=create-drop
  spring.datasource.driver-class-name=org.h2.Driver
  spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

Running Tests

To run all test cases:

mvn clean test

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