Add Kotlin example for Spring Data MongoDB.
This commit is contained in:
Mark Paluch
committed by
Oliver Gierke
Oliver Gierke
parent
fdca9980a9
commit
2224264499
56
mongodb/kotlin/README.md
Normal file
56
mongodb/kotlin/README.md
Normal file
@@ -0,0 +1,56 @@
|
||||
# Spring Data MongoDB - Kotlin examples
|
||||
|
||||
This project contains samples of Kotlin-specific features of Spring Data (MongoDB).
|
||||
|
||||
## Value defaulting on entity construction
|
||||
|
||||
Kotlin allows defaulting for constructor- and method arguments.
|
||||
Defaulting allows usage of substitute values if a field in the document is absent or simply `null`.
|
||||
Spring Data inspects objects whether they are Kotlin types and uses the appropriate constructor.
|
||||
|
||||
```kotlin
|
||||
data class Person (@Id val id: String?, val firstname: String? = "Walter", val lastname: String)
|
||||
|
||||
operations.insert<Document>().inCollection("person").one(Document("lastname", "White"))
|
||||
|
||||
val walter = operations.findOne<Document>(query(where("lastname").isEqualTo("White")), "person")
|
||||
|
||||
assertThat(walter.firstname).isEqualTo("Walter")
|
||||
```
|
||||
|
||||
## Kotlin Extensions
|
||||
|
||||
Spring Data exposes methods accepting a target type to either query for or to project results values on.
|
||||
Kotlin represents classes with its own type, `KClass` which can be an obstacle when attempting to obtain a Java `Class` type.
|
||||
|
||||
Spring Data ships with extensions that add overloads for methods accepting a type parameter by either leveraging generics or accepting `KClass` directly.
|
||||
|
||||
```kotlin
|
||||
operations.getCollectionName<Person>()
|
||||
|
||||
operations.getCollectionName(Person::class)
|
||||
```
|
||||
|
||||
## Nullability
|
||||
|
||||
Declaring repository interfaces using Kotlin allows expressing nullability constraints on arguments and return types. Spring Data evaluates nullability of arguments and return types and reacts to these. Passing `null` to a non-nullable argument raises an `IllegalArgumentException`, as you're already used to from Kotlin. Spring Data helps you also to prevent `null` in query results. If you wish to return a nullable result, use Kotlin's nullability marker `?`. To prevent `null` results, declare the return type of a query method as non-nullable. In the case a query yields no result, a non-nullable query method throws `EmptyResultDataAccessException`.
|
||||
|
||||
```kotlin
|
||||
interface PersonRepository : CrudRepository<Person, String> {
|
||||
|
||||
/**
|
||||
* Query method declaring a nullable return type that allows to return null values.
|
||||
*/
|
||||
fun findOneOrNoneByFirstname(firstname: String): Person?
|
||||
|
||||
/**
|
||||
* Query method declaring a nullable argument.
|
||||
*/
|
||||
fun findNullableByFirstname(firstname: String?): Person?
|
||||
|
||||
/**
|
||||
* Query method requiring a result. Throws [org.springframework.dao.EmptyResultDataAccessException] if no result is found.
|
||||
*/
|
||||
fun findOneByFirstname(firstname: String): Person
|
||||
}
|
||||
```
|
||||
55
mongodb/kotlin/pom.xml
Normal file
55
mongodb/kotlin/pom.xml
Normal file
@@ -0,0 +1,55 @@
|
||||
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
|
||||
<parent>
|
||||
<groupId>org.springframework.data.examples</groupId>
|
||||
<artifactId>spring-data-mongodb-examples</artifactId>
|
||||
<version>2.0.0.BUILD-SNAPSHOT</version>
|
||||
</parent>
|
||||
|
||||
<artifactId>spring-data-mongodb-kotlin</artifactId>
|
||||
<name>Spring Data MongoDB - Kotlin features</name>
|
||||
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.jetbrains.kotlin</groupId>
|
||||
<artifactId>kotlin-stdlib-jdk8</artifactId>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.jetbrains.kotlin</groupId>
|
||||
<artifactId>kotlin-reflect</artifactId>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
|
||||
<build>
|
||||
<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
|
||||
<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
|
||||
<plugins>
|
||||
<plugin>
|
||||
<groupId>org.springframework.boot</groupId>
|
||||
<artifactId>spring-boot-maven-plugin</artifactId>
|
||||
</plugin>
|
||||
<plugin>
|
||||
<artifactId>kotlin-maven-plugin</artifactId>
|
||||
<groupId>org.jetbrains.kotlin</groupId>
|
||||
<configuration>
|
||||
<args>
|
||||
<arg>-Xjsr305=strict</arg>
|
||||
</args>
|
||||
<compilerPlugins>
|
||||
<plugin>spring</plugin>
|
||||
</compilerPlugins>
|
||||
</configuration>
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.jetbrains.kotlin</groupId>
|
||||
<artifactId>kotlin-maven-allopen</artifactId>
|
||||
<version>${kotlin.version}</version>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
</plugin>
|
||||
</plugins>
|
||||
</build>
|
||||
|
||||
</project>
|
||||
@@ -0,0 +1,29 @@
|
||||
/*
|
||||
* Copyright 2018 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package example.springdata.mongodb.people
|
||||
|
||||
import org.springframework.boot.autoconfigure.SpringBootApplication
|
||||
import org.springframework.boot.runApplication
|
||||
|
||||
/**
|
||||
* @author Mark Paluch
|
||||
*/
|
||||
@SpringBootApplication
|
||||
class ApplicationConfiguration
|
||||
|
||||
fun main(args: Array<String>) {
|
||||
runApplication<ApplicationConfiguration>(*args)
|
||||
}
|
||||
@@ -0,0 +1,28 @@
|
||||
/*
|
||||
* Copyright 2018 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package example.springdata.mongodb.people
|
||||
|
||||
import org.springframework.data.annotation.Id
|
||||
import org.springframework.data.annotation.PersistenceConstructor
|
||||
|
||||
/**
|
||||
* An entity to represent a Person.
|
||||
*
|
||||
* @author Mark Paluch
|
||||
*/
|
||||
data class Person @PersistenceConstructor constructor(@Id val id: String?, val firstname: String? = "Walter", val lastname: String = "") {
|
||||
constructor(firstname: String?, lastname: String) : this(null, firstname, lastname);
|
||||
}
|
||||
@@ -0,0 +1,41 @@
|
||||
/*
|
||||
* Copyright 2018 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package example.springdata.mongodb.people
|
||||
|
||||
import org.springframework.data.repository.CrudRepository
|
||||
|
||||
/**
|
||||
* Repository interface to manage [Person] instances.
|
||||
*
|
||||
* @author Mark Paluch
|
||||
*/
|
||||
interface PersonRepository : CrudRepository<Person, String> {
|
||||
|
||||
/**
|
||||
* Query method declaring a nullable return type that allows to return null values.
|
||||
*/
|
||||
fun findOneOrNoneByFirstname(firstname: String): Person?
|
||||
|
||||
/**
|
||||
* Query method declaring a nullable argument.
|
||||
*/
|
||||
fun findNullableByFirstname(firstname: String?): Person?
|
||||
|
||||
/**
|
||||
* Query method requiring a result. Throws [org.springframework.dao.EmptyResultDataAccessException] if no result is found.
|
||||
*/
|
||||
fun findOneByFirstname(firstname: String): Person
|
||||
}
|
||||
@@ -0,0 +1,85 @@
|
||||
/*
|
||||
* Copyright 2018 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package example.springdata.mongodb.people
|
||||
|
||||
import org.assertj.core.api.Assertions.assertThat
|
||||
import org.assertj.core.api.Assertions.assertThatThrownBy
|
||||
import org.junit.Before
|
||||
import org.junit.Test
|
||||
import org.junit.runner.RunWith
|
||||
import org.springframework.beans.factory.annotation.Autowired
|
||||
import org.springframework.boot.test.context.SpringBootTest
|
||||
import org.springframework.dao.EmptyResultDataAccessException
|
||||
import org.springframework.test.context.junit4.SpringRunner
|
||||
|
||||
/**
|
||||
* Tests showing Kotlin usage of Spring Data Repositories.
|
||||
*
|
||||
* @author Mark Paluch
|
||||
*/
|
||||
@RunWith(SpringRunner::class)
|
||||
@SpringBootTest
|
||||
class RepositoryTests {
|
||||
|
||||
@Autowired
|
||||
lateinit var repository: PersonRepository
|
||||
|
||||
@Before
|
||||
fun before() {
|
||||
repository.deleteAll()
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should find one person`() {
|
||||
|
||||
repository.save(Person("Walter", "White"))
|
||||
|
||||
val walter = repository.findOneByFirstname("Walter")
|
||||
|
||||
assertThat(walter).isNotNull()
|
||||
assertThat(walter.firstname).isEqualTo("Walter")
|
||||
assertThat(walter.lastname).isEqualTo("White")
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should return null if no person found`() {
|
||||
|
||||
repository.save(Person("Walter", "White"))
|
||||
|
||||
val walter = repository.findOneOrNoneByFirstname("Hank")
|
||||
|
||||
assertThat(walter).isNull()
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should throw EmptyResultDataAccessException if no person found`() {
|
||||
|
||||
repository.save(Person("Walter", "White"))
|
||||
|
||||
assertThatThrownBy { repository.findOneByFirstname("Hank") }.isInstanceOf(EmptyResultDataAccessException::class.java)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should accept nullable parameters`() {
|
||||
|
||||
repository.save(Person(null, "Heisenberg"))
|
||||
|
||||
val heisenberg = repository.findNullableByFirstname(null)
|
||||
|
||||
assertThat(heisenberg).isNotNull()
|
||||
assertThat(heisenberg!!.lastname).isEqualTo("Heisenberg")
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,126 @@
|
||||
/*
|
||||
* Copyright 2018 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package example.springdata.mongodb.people
|
||||
|
||||
import org.assertj.core.api.Assertions.assertThat
|
||||
import org.bson.Document
|
||||
import org.junit.Before
|
||||
import org.junit.Test
|
||||
import org.junit.runner.RunWith
|
||||
import org.springframework.beans.factory.annotation.Autowired
|
||||
import org.springframework.boot.test.context.SpringBootTest
|
||||
import org.springframework.data.mongodb.core.*
|
||||
import org.springframework.data.mongodb.core.query.Criteria.where
|
||||
import org.springframework.data.mongodb.core.query.Query.query
|
||||
import org.springframework.data.mongodb.core.query.isEqualTo
|
||||
import org.springframework.test.context.junit4.SpringRunner
|
||||
|
||||
/**
|
||||
* Tests showing Kotlin usage of [MongoTemplate] and its Kotlin extensions.
|
||||
*
|
||||
* @author Mark Paluch
|
||||
*/
|
||||
@RunWith(SpringRunner::class)
|
||||
@SpringBootTest
|
||||
class TemplateTests {
|
||||
|
||||
@Autowired
|
||||
lateinit var operations: MongoOperations
|
||||
|
||||
@Before
|
||||
fun before() {
|
||||
operations.dropCollection<Person>()
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should create collection leveraging reified type parameters`() {
|
||||
|
||||
operations.createCollection<Person>()
|
||||
|
||||
assertThat(operations.collectionNames).contains("person")
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should insert and find person in a fluent API style`() {
|
||||
|
||||
operations.insert<Person>().inCollection("person").one(Person("Walter", "White"))
|
||||
|
||||
val people = operations.query<Person>()
|
||||
.matching(query(where("firstname").isEqualTo("Walter")))
|
||||
.all()
|
||||
|
||||
assertThat(people).hasSize(1).extracting("firstname").containsOnly("Walter")
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should insert and project query results`() {
|
||||
|
||||
operations.insert<Person>().inCollection("person").one(Person("Walter", "White"))
|
||||
|
||||
val firstnameOnly = operations.query<Person>()
|
||||
.asType<FirstnameOnly>()
|
||||
.matching(query(where("firstname").isEqualTo("Walter")))
|
||||
.oneValue()
|
||||
|
||||
assertThat(firstnameOnly?.getFirstname()).isEqualTo("Walter")
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should insert and count objects in a fluent API style`() {
|
||||
|
||||
operations.insert<Person>().inCollection("person").one(Person("Walter", "White"))
|
||||
|
||||
val count = operations.query<Person>()
|
||||
.matching(query(where("firstname").isEqualTo("Walter")))
|
||||
.count()
|
||||
|
||||
assertThat(count).isEqualTo(1)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should insert and find person`() {
|
||||
|
||||
val person = Person("Walter", "White")
|
||||
|
||||
operations.insert(person)
|
||||
|
||||
val people = operations.find<Person>(query(where("firstname").isEqualTo("Walter")))
|
||||
|
||||
assertThat(people).hasSize(1).extracting("firstname").containsOnly("Walter")
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `should apply defaulting for absent properties`() {
|
||||
|
||||
operations.insert<Document>().inCollection("person").one(Document("lastname", "White"))
|
||||
|
||||
val person = operations.query<Person>()
|
||||
.matching(query(where("lastname").isEqualTo("White")))
|
||||
.firstValue()!!
|
||||
|
||||
assertThat(person.firstname).isEqualTo("Walter")
|
||||
assertThat(person.lastname).isEqualTo("White")
|
||||
|
||||
|
||||
val walter = operations.findOne<Document>(query(where("lastname").isEqualTo("White")), "person")
|
||||
|
||||
assertThat(walter).isNotNull.containsEntry("lastname", "White").containsOnlyKeys("_id", "lastname")
|
||||
}
|
||||
|
||||
interface FirstnameOnly {
|
||||
fun getFirstname(): String
|
||||
}
|
||||
}
|
||||
@@ -24,6 +24,7 @@
|
||||
<module>geo-json</module>
|
||||
<module>gridfs</module>
|
||||
<module>java8</module>
|
||||
<module>kotlin</module>
|
||||
<module>query-by-example</module>
|
||||
<module>reactive</module>
|
||||
<module>security</module>
|
||||
@@ -32,7 +33,7 @@
|
||||
<module>schema-validation</module>
|
||||
<module>util</module>
|
||||
</modules>
|
||||
|
||||
|
||||
<properties>
|
||||
<embedded-mongo.version>2.1.1</embedded-mongo.version>
|
||||
</properties>
|
||||
|
||||
Reference in New Issue
Block a user