kgoralski / kotlin-springboot-template

Playground: Kotlin, Spring Boot, REST JAX-RS, Sprind Data JPA, Spring Data REST, Apache Cassandra, Tests with Spock, Gradle Kotlin Script

Kotlin Spring Boot Application Scaffold

You are using it at your own risk. It is playground project. Very quickie. For production it need a little bit more. :)

About:

• Kotlin
• Spring Boot
• REST JAX-RS and Jersey Proxy Client
• HATEOAS Example
• Sprind Data JPA with H2 Database
• Spring Data NoSQL with Apache Cassandra (from Docker for App, embedded for Tests)
• Spring Data REST
• Tests with Spock
• Gradle Kotlin Script with multi modules

How to run it?

• gradle clean bootRepackage
• docker start cassandradb-2.1.16
• java -jar kotlinboot-server-0.0.1-SNAPSHOT.jar

Endpoints JAX-RS for Apache Cassandra

• GET http://localhost:8080/rest/books/
• GET http://localhost:8080/rest/books/1
• POST http://localhost:8080/rest/books/ { BookDto }
• PUT http://localhost:8080/rest/books/1 { BookDto }
• DELETE http://localhost:8080/rest/books/1
• DELETE http://localhost:8080/rest/books/
• GET http://localhost:8080/rest/books/find?title=Hobbit

Spring Data REST with H2 Database (JPA)

• Exposing Spring Data Repositories to the world
• With all features like: paging sorting, even custom queries like:

http://localhost:8080/authors/search/findByFirstName?name=Steven

• Create Entity, Repository and Endpoints will be created by Spring

// http://localhost:8080/authors/
{
  "_embedded" : {
    "authors" : [ {
      "firstName" : "Steven",
      "lastName" : "Erikson",
      "_links" : {
        "self" : {
          "href" : "http://localhost:8080/authors/1"
        },
        "author" : {
          "href" : "http://localhost:8080/authors/1"
        }
      }
    } ]
  },
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/authors"
    },
    "profile" : {
      "href" : "http://localhost:8080/profile/authors"
    },
    "search" : {
      "href" : "http://localhost:8080/authors/search"
    }
  },
  "page" : {
    "size" : 20,
    "totalElements" : 1,
    "totalPages" : 1,
    "number" : 0
  }
}

HATEOAS Example

{
	"id": "56a915f0-cb9b-11e6-8d84-59dd97b77ed0",
	"title": "title",
	"author": "author",
	"cover": "cover",
	"fullName": "author title",
	"links": [
		{
			"rel": "self",
			"href": "http://localhost:8080/rest/books/hateoas/56a915f0-cb9b-11e6-8d84-59dd97b77ed0"
		}
	]
}

Apache Cassandra and Docker (for easy setup)

• Apache Cassandra 2.x.x (Used for this project)

docker run --name cassandradb-2.1.16 -p "7191:7191" -p "7000:7000" -p "7001:7001" -p "9160:9160" -p "9042:9042" -d cassandra:2.1.16

• Apache Cassandra 3.x.x works with Spring Boot 2.0.0 RELEASE

docker run --name cassandradb -p "7191:7191" -p "7000:7000" -p "7001:7001" -p "9160:9160" -p "9042:9042" -d cassandra:latest

You may need to add this to build.gradle.kts for Apache Cassandra 3.x.x

buildscript {
    val springBootVersion = "2.0.0.BUILD-SNAPSHOT"
	var springSnapshot: String by extra
	springSnapshot = "https://repo.spring.io/snapshot"
	var springMilestone: String by extra
	springMilestone = "https://repo.spring.io/milestone"

	repositories {
		maven{setUrl(springSnapshot)}
		maven{setUrl(springMilestone)}
	}
dependencies {	
	testCompile("org.cassandraunit:cassandra-unit-spring:3.1.1.0")
	}	
}

• Script

CREATE KEYSPACE IF NOT EXISTS booksdb WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
CREATE TABLE IF NOT EXISTS booksdb.books (id TimeUUID PRIMARY KEY, title text, author text, cover text);
CREATE INDEX IF NOT EXISTS booktitleindex ON booksdb.books(title);
CREATE INDEX IF NOT EXISTS bookauthorindex ON booksdb.books(author);

You can connect to Cassandra inside docker with http://dbeaver.jkiss.org/download/enterprise/ Using cassandra/cassandra login/pass to localhost:9042

• Database inside Docker? Be warned.

Intellij IDEA

• Gradle Kotlin Script :"This sample should work against the latest Kotlin plugin, 1.1-M02-12 at the time of this writing, from the Early Access Preview 1.1 channel accessible via the Configure Kotlin Plugin Updates action." https://github.com/gradle/gradle-script-kotlin/tree/master/samples
• Running Spock tests inside Eclipse might be difficult

References

• https://github.com/sdeleuze/spring-boot-kotlin-demo
• https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-data-cassandra
• http://stackoverflow.com/questions/36975997/cassandra-3-5-compatablity-with-spring-data-1-4
• https://www.javacodegeeks.com/2015/01/building-a-hateoas-api-with-jax-rs-and-spring.html
• Introducing Kotlin support in Spring Framework 5.0!