spring-data-elasticsearch/README.adoc

image:https://spring.io/badges/spring-data-elasticsearch/ga.svg[Spring Data Elasticsearch,link=https://projects.spring.io/spring-data-elasticsearch#quick-start] image:https://spring.io/badges/spring-data-elasticsearch/snapshot.svg[Spring Data Elasticsearch,link=https://projects.spring.io/spring-data-elasticsearch#quick-start]

= Spring Data for Elasticsearch image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-elasticsearch%2Fmain&subject=Build[link=https://jenkins.spring.io/view/SpringData/job/spring-data-elasticsearch/] https://gitter.im/spring-projects/spring-data[image:https://badges.gitter.im/spring-projects/spring-data.svg[Gitter]]

The primary goal of the https://projects.spring.io/spring-data[Spring Data] project is to make it easier to build Spring-powered applications that use new data access technologies such as non-relational databases, map-reduce frameworks, and cloud based data services.

The Spring Data Elasticsearch project provides integration with the https://www.elastic.co/[Elasticsearch] search engine.
Key functional areas of Spring Data Elasticsearch are a POJO centric model for interacting with a Elasticsearch Documents and easily writing a Repository style data access layer.

This project is lead and maintained by the community.

== Features

* Spring configuration support using Java based `@Configuration` classes or an XML namespace for a ES clients instances.
* `ElasticsearchOperations` class and implementations that increases productivity performing common ES operations.
Includes integrated object mapping between documents and POJOs.
* Feature Rich Object Mapping integrated with Spring’s Conversion Service
* Annotation based mapping metadata
* Automatic implementation of `Repository` interfaces including support for custom search methods.
* CDI support for repositories

== About Elasticsearch versions and clients

=== Elasticsearch 7.17 client libraries

At the end of 2021 Elasticsearch with version 7.17 released the new version of their Java client and deprecated the `RestHighLevelCLient` which was the default way to access Elasticsearch up to then.

Spring Data Elasticsearch will in version 4.4 offer the possibility to optionally use the new client as an alternative to the existing setup using the `RestHighLevelCLient`.
The default client that is used still is the `RestHighLevelCLient`, first because the integration of the new client is not yet complete, the new client still has features missing and bugs which will hopefully be resolved soon.
Second, and more important, the new Elasticsearch client forces users to switch from using `javax.json.spi.JsonProvider` to `jakarta.json.spi.JsonProvider`.
Spring Data Elasticsearch cannot enforce this switch; Spring Boot will switch to `jakarta` with version 3 and then it's safe for Spring Data Elasticsearch to switch to the new client.

So for version 4.4 Spring Data Elasticsearch will keep using the `RestHighLevelCLient` in version 7.17.x (as long as this will be available).

=== Elasticsearch 8 client libraries

In Elasticsearch 8, the `RestHighLevelCLient` has been removed.
This means that a switch to this client version can only be done with the next major upgrade which will be Spring Data Elasticsearch 5, based on Spring Data 3, used by Spring Boot 3, based on Spring 6 and Java 17.

=== Elasticsearch 8 cluster

It should be possible to use the Elasticsearch 7 client to access a cluster running version 8 by setting the appropriate compatibility headers (see the documentation at https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#elasticsearch.clients.configuration). but I encountered and heard of cases where the response from the server is not parseable by the client although the headers are set, so use with care.

== Code of Conduct

This project is governed by the https://github.com/spring-projects/.github/blob/e3cc2ff230d8f1dca06535aa6b5a4a23815861d4/CODE_OF_CONDUCT.md[Spring Code of Conduct].
By participating, you are expected to uphold this code of conduct.
Please report unacceptable behavior to spring-code-of-conduct@pivotal.io.

== Getting Started

Here is a quick teaser of an application using Spring Data Repositories in Java:

[source,java]
----
public interface PersonRepository extends CrudRepository<Person, Long> {

  List<Person> findByLastname(String lastname);

  List<Person> findByFirstnameLike(String firstname);
}

@Service
public class MyService {

  private final PersonRepository repository;

  public MyService(PersonRepository repository) {
    this.repository = repository;
  }

  public void doWork() {

    repository.deleteAll();

    Person person = new Person();
    person.setFirstname("Oliver");
    person.setLastname("Gierke");
    repository.save(person);

    List<Person> lastNameResults = repository.findByLastname("Gierke");
    List<Person> firstNameResults = repository.findByFirstnameLike("Oli");
 }
}
----

=== Using the RestClient

Provide a configuration like this:

[source,java]
----
@Configuration
public class RestClientConfig extends AbstractElasticsearchConfiguration {

    @Override
    @Bean
    public RestHighLevelClient elasticsearchClient() {

        final ClientConfiguration clientConfiguration = ClientConfiguration.builder()
            .connectedTo("localhost:9200")
            .build();

        return RestClients.create(clientConfiguration).rest();
    }
}
----

=== Maven configuration

Add the Maven dependency:

[source,xml]
----
<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-elasticsearch</artifactId>
  <version>${version}</version>
</dependency>
----

// NOTE: since Github does not support include directives, the content of
// the src/main/asciidoc/reference/preface.adoc file is duplicated here
// Always change both files!
**Compatibility Matrix**

The compatibility between Spring Data Elasticsearch, Elasticsearch client drivers and Spring Boot versions can be found in the https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#preface.versions[reference documentation].

To use the Release candidate versions of the upcoming major version, use our Maven milestone repository and declare the appropriate dependency version:

[source,xml]
----
<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-elasticsearch</artifactId>
  <version>${version}.RCx</version> <!-- x being 1, 2, ... -->
</dependency>

<repository>
  <id>spring-snapshot</id>
  <name>Spring Snapshot Repository</name>
  <url>https://repo.spring.io/milestone</url>
</repository>
----

If you'd rather like the latest snapshots of the upcoming major version, use our Maven snapshot repository and declare the appropriate dependency version:

[source,xml]
----
<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-elasticsearch</artifactId>
  <version>${version}-SNAPSHOT</version>
</dependency>

<repository>
  <id>spring-snapshot</id>
  <name>Spring Snapshot Repository</name>
  <url>https://repo.spring.io/snapshot</url>
</repository>
----

== Getting Help

Having trouble with Spring Data?
We’d love to help!

* Check the
https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/[reference documentation], and https://docs.spring.io/spring-data/elasticsearch/docs/current/api/[Javadocs].
* Learn the Spring basics – Spring Data builds on Spring Framework, check the https://spring.io[spring.io] web-site for a wealth of reference documentation.
If you are just starting out with Spring, try one of the https://spring.io/guides[guides].
* Ask a question - we monitor https://stackoverflow.com[stackoverflow.com] for questions tagged with https://stackoverflow.com/tags/spring-data[`spring-data-elasticsearch`].
You can also chat with the community on https://gitter.im/spring-projects/spring-data[Gitter].
* Report bugs with Spring Data for Elasticsearch at https://github.com/spring-projects/spring-data-elasticsearch/issues[https://github.com/spring-projects/spring-data-elasticsearch/issues].

== Reporting Issues

Spring Data uses GitHub as issue tracking system to record bugs and feature requests.
If you want to raise an issue, please follow the recommendations below:

* Before you log a bug, please search the
https://github.com/spring-projects/spring-data-elasticsearch/issues[issue tracker] to see if someone has already reported the problem.
* If the issue doesn’t already exist, https://github.com/spring-projects/spring-data-elasticsearch/issues/new[create a new issue].
* Please provide as much information as possible with the issue report, we like to know the version of Spring Data Elasticsearch that you are using and JVM version.
* If you need to paste code, or include a stack trace use Markdown +++```+++ escapes before and after your text.
* If possible try to create a test-case or project that replicates the issue.
Attach a link to your code or a compressed file containing your code.

== Building from Source

You don’t need to build from source to use Spring Data (binaries in https://repo.spring.io[repo.spring.io]), but if you want to try out the latest and greatest, Spring Data can be easily built with the https://github.com/takari/maven-wrapper[maven wrapper].

You need JDK 17 or above to build the _main_ branch.
For the branches up to and including release 4.4, JDK 8 is required.

[source,bash]
----
 $ ./mvnw clean install
----

If you want to build with the regular `mvn` command, you will need https://maven.apache.org/run-maven/index.html[Maven v3.5.0 or above].

_Also see link:CONTRIBUTING.adoc[CONTRIBUTING.adoc] if you wish to submit pull requests, and in particular please sign the https://cla.pivotal.io/sign/spring[Contributor’s Agreement] before submitting your first pull request._

IMPORTANT: When contributing, please make sure an issue exists in https://github.com/spring-projects/spring-data-elasticsearch/issues[issue tracker] and comment on this issue with how you want to address it.
By this we not only know that someone is working on an issue, we can also align architectural questions and possible solutions before work is invested . We so can prevent that much work is put into Pull Requests that have little or no chances of being merged.

=== Building reference documentation

Building the documentation builds also the project without running tests.

[source,bash]
----
 $ ./mvnw clean install -Pdistribute
----

The generated documentation is available from `target/site/reference/html/index.html`.

== Examples

For examples on using the Spring Data for Elasticsearch, see the https://github.com/spring-projects/spring-data-examples/tree/main/elasticsearch/example[spring-data-examples] project.

== License

Spring Data for Elasticsearch Open Source software released under the https://www.apache.org/licenses/LICENSE-2.0.html[Apache 2.0 license].