This is a Spring-based showcasing the use of Crnk. Further smaller example applications integrating into various frameworks can be found at crnk-examples.
WARNING: this example project is still in development and subject to various improvements, see roadmap
Crnk requires Java 8 or later.
Crnk is licensed under the Apache License, Version 2.0. You can grab a copy of the license at http://www.apache.org/licenses/LICENSE-2.0.
Crnk make use of Gradle for its build. To build the project run
gradlew build
In order to run this example do:
gradlew run
or
docker run --name=crnk -p 8080:8080 crnk/example
The JSON API endpoint will be available at:
http://localhost:8080/api/
Some further URLs to play around that show the power of Crnk:
http://127.0.0.1:8080/api/movie
http://127.0.0.1:8080/api/movie/44cda6d4-1118-3600-9cab-da760bfd678c
http://127.0.0.1:8080/api/movie/44cda6d4-1118-3600-9cab-da760bfd678c
http://127.0.0.1:8080/api/movie/44cda6d4-1118-3600-9cab-da760bfd678c/project
http://127.0.0.1:8080/api/movie/44cda6d4-1118-3600-9cab-da760bfd678c/relationships/project
http://127.0.0.1:8080/api/movie?sort=-name
http://127.0.0.1:8080/api/movie?sort=-id,name
http://127.0.0.1:8080/api/movie?sort=id&page[offset]=0&page[limit]=2
http://127.0.0.1:8080/api/movie?filter[name]=Iron Man
http://127.0.0.1:8080/api/movie?filter[name][EQ]=Iron Man
http://127.0.0.1:8080/api/movie?filter[name][LIKE]=Iron
http://127.0.0.1:8080/api/schedule
http://127.0.0.1:8080/api/meta/resource
http://127.0.0.1:8080/api/vote?fields=name // demos fields set & performance issues
http://127.0.0.1:8080/api/secrets // demos error
The crnk-example-service project showcases:
- Integration of Crnk into Spring Boot
- Exposing entities with crnk-jpa using
MovieRepository,PersonRepository, etc. extendingJpaEntityRepositoryBase. Behind the scenes theQuerySpecis translated to an efficient JPA Criteria query. - A simple in-memory repository with
ScreeningRepositorythat keeps all resources in a map. - A manually written repository with
VoteRepository. It makes use of Thread.sleep to simulate heavy work. - A custom exception is introduced with
CustomExceptionMapperthat is mapped to a JSON API error and HTTP status code. - using
@JsonApiRelationIdwithScreeningRepositoryto handle use cases where the related ID is easy to get, which in turn allows to omit having to implement relationship repositories. - implementing a relationship repository with
AttributeChangeRelationshipRepository. - introducing new relationships to existing resources
without touching those resources with
AttributeChangeFieldProvider. - delivery of an Angular frontend application accessing the JSON API endpoint.
SecurityConfigurationperforms a OAuth setup with GitHub as provider.LoginRepositorygives access to information about the logged-in user through http://localhost:8080/api/login. Enable spring security in theapplication.yamlto make use of the security features. Security is disabled by default to facilitate playing with the example app. The security setup is still work in progress. Currently the Angular app makes use of a session token and the Spring backend takes care of interacting with the GitHub OAuth provider. In the future we may switch to a session-less, token-based setup (PRs welcomed).CSRF(resp.XSRFin Angular terminology) protection throughSecurityConfiguration.ExampleSecurityConfigurerto setup role-based access control.ExampleDecoratorFactoryto intercept and modify requests to repositories.
The TestDataLoader will automatically setup some test data upon start.
Note that the project is structured based on the the use Crnk features like JPA or decoration. For real-world application we do not recommend that, but rather structure the application based on business value.
Feedback and PRs very welcomed!