Example project using Spring Boot, Spring Cloud, Open Feign and Java 11.
Spring Boot and Spring Cloud were chosen as they make really easy to stand up a new project. Java 11 is chosen because Java 8 is no longer supported by Oracle plus the libraries chosen already support Java 11.
Open Feign makes a good choice to consume an API. This services consumes the Open Weather Map API. There is an ErrorDecoder to catch any non 200 errors from the API.
Spring Validation is used to ensure the city name size is between 1 and 100. These limits were chosen arbitrarily. I would've also used a regular expression, but I haven't checked which characters are valid in the Open Weather Map API.
The service is divided in the following layers:
- client For Feign clients.
- controller For endpoints and user input validation.
- dto To pass information between the service layer, controller layer and final API user.
- model Maps the objects return by the API in this case.
- service Business logic. In this case it transforms the results we get from the Open Weather Map API
There is a similar division for the tests. Most classes that end with Tests are Unit Tests.
ForecastControllerIntegrationTests contains Integration tests.
Swagger is chosen to document the API and it can be found in http://localhost:8080/forecasts/swagger-ui.html when the application is running. It can also be used to test the API
The easiest way to run this project is with Gradle Wrapper.
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Replace the value
<insert-api-key-here>ofservice.open-weather-map.api-keyin the filesrc/main/resources/application.yml. Alternatively you can provide aSERVICE_OPEN-WEATHER-MAP_API-KEYenvironment variable. -
Open the terminal
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Navigate to the folder in which the project is located
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Execute
gradlew.bat bootRunin Windows orgradlew bootRunin MacOS/Linux. -
Execute the following command in your terminal in MacOS/Linux or equivalent in Windows
curl 'http://localhost:8080/forecasts/data?cityName=Berlin'