Quick Intro
Spring Boot is an open source java based framework which makes it easy to create stand-alone, production-grade java based applications that you can “just run”. Elasticsearch, on the other hand, is a distributed, RESTful search and analytics engine capable of addressing a growing number of use cases amongst which is providing full text search for a spring base web application.
Add dependencies
Add to the following into the <dependencies> tag of your application’s pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
<!-- Spring Data Jest dependencies for Elasticsearch -->
<dependency>
<groupId>com.github.vanroy</groupId>
<artifactId>spring-boot-starter-data-jest</artifactId>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- log4j2-mock needed to create embedded elasticsearch instance with SLF4J -->
<dependency>
<groupId>de.dentrassi.elasticsearch</groupId>
<artifactId>log4j2-mock</artifactId>
<version>0.0.2</version>
<scope>runtime</scope>
</dependency>Add Elasticsearch configuration
Suppose your project root package is com.springbootelasticsearchdemo.repository.search,
add the following configuration class.
@Configuration
@EnableConfigurationProperties(ElasticsearchProperties.class)
@EnableElasticsearchRepositories("com.springbootelasticsearchdemo.repository.search")
public class ElasticsearchConfiguration {
private ObjectMapper mapper;
public ElasticsearchConfiguration(ObjectMapper mapper) {
this.mapper = mapper;
}
@Bean
public EntityMapper getEntityMapper() {
return new CustomEntityMapper(mapper);
}
@Bean
@Primary
public ElasticsearchOperations elasticsearchTemplate(final JestClient jestClient,
final ElasticsearchConverter elasticsearchConverter,
final SimpleElasticsearchMappingContext simpleElasticsearchMappingContext,
EntityMapper mapper) {
return new JestElasticsearchTemplate(
jestClient,
elasticsearchConverter,
new DefaultJestResultsMapper(simpleElasticsearchMappingContext, mapper));
}
public class CustomEntityMapper implements EntityMapper {
private ObjectMapper objectMapper;
public CustomEntityMapper(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
objectMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
objectMapper.configure(SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS, true);
objectMapper.configure(SerializationFeature.INDENT_OUTPUT, false);
objectMapper.configure(DeserializationFeature.READ_DATE_TIMESTAMPS_AS_NANOSECONDS, true);
}
@Override
public String mapToString(Object object) throws IOException {
return objectMapper.writeValueAsString(object);
}
@Override
public <T> T mapToObject(String source, Class<T> clazz) throws IOException {
return objectMapper.readValue(source, clazz);
}
@Override
public Map<String, Object> mapObject(Object source) {
try {
return objectMapper.readValue(mapToString(source), HashMap.class);
} catch (IOException e) {
throw new MappingException(e.getMessage(), e);
}
}
@Override
public <T> T readObject (Map<String, Object> source, Class<T> targetType) {
try {
return mapToObject(mapToString(source), targetType);
} catch (IOException e) {
throw new MappingException(e.getMessage(), e);
}
}
}
}Specify which entities to index
Add this annotation to the top of each Entity which you want to be index.
@org.springframework.data.elasticsearch.annotations.Document(indexName = "blog")What about Entity fields and Enums? Taken care of.
Add repositories for accessing search indices
Add an ElasticsearchRepository for each entity which you want to be searchable
public interface BlogSearchRepository extends ElasticsearchRepository<Blog, Long> {
}Use the ElasticsearchRepository in your Service class
import com.springbootelasticsearchdemo.repository.search.BlogSearchRepository;
import static org.elasticsearch.index.query.QueryBuilders.queryStringQuery;
public class BlogService{
private final BlogSearchRepository blogSearchRepository;
public BlogService(BlogSearchRepository blogSearchRepository) {
this.blogSearchRepository = blogSearchRepository;
}
public Page<Blog> search(String query, Pageable pageable) {
return this.blogSearchRepository.search(queryStringQuery(query), pageable);
}
}Notes
Before you run your application in dev you should stand up an elasticsearch
server via the following command:
docker run -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" docker.elastic.co/elasticsearch/elasticsearch:6.8.6Make sure the elasticsearch version (in this case 6.8.6) is compatible with
that which comes with spring-boot-starter-data-elasticsearch