Tag Archives: GET

Elasticsearch REST JAVA Client to get Index Details List


Below is example to get Index Detail in Java Array by using Elasticsearch REST Java client. Here client will call endpoint  “/_cat/indices?format=json” to retrieve all detail of index list. It is same as we use GET by CURL

GET http://elasticsearchHost:9200/_cat/indices?format=json
 

Pre-requisite

  • Minimum requirement for Java 7 version required.
  • Add below dependency for Elasticsearch REST and JSON Mapping in your pom.xml or add in your class path.

Dependency

<!--Elasticsearch REST jar-->
<dependency>
			<groupId>org.elasticsearch.client</groupId>
			<artifactId>rest</artifactId>
			<version>5.1.2</version>
</dependency>
<!--Jackson jar for mapping json to Java -->
<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>2.8.5</version>
</dependency>

Sample Code

import java.io.IOException;
import java.util.Collections;

import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;

import com.fasterxml.jackson.databind.ObjectMapper;

public class ElasticsearchRESTIndexClient {

	public static void main(String[] args) {
		IndexInfo []indexArr = null;
		RestClient client = null;
		try {
			client = openConnection();
			if (client != null) {
				// performRequest GET method will retrieve all index detail list
				// information from elastic server
				Response response = client.performRequest("GET", "/_cat/indices?format=json",
						Collections.singletonMap("pretty", "true"));
				// GetEntity api will return content of response in form of json
				// in Http Entity
				HttpEntity entity = response.getEntity();
				ObjectMapper jacksonObjectMapper = new ObjectMapper();
				// Map json response to Java object in IndexInfo Array
				// Cluster Info
				indexArr = jacksonObjectMapper.readValue(entity.getContent(), IndexInfo[].class);
				for(IndexInfo indexInfo:indexArr)
				{
				System.out.println(indexInfo);
			    }
			}

		} catch (Exception ex) {
			System.out.println("Exception found while getting cluster detail");
			ex.printStackTrace();
		} finally {
			closeConnnection(client);
		}

	}

	// Get Rest client connection
	private static RestClient openConnection() {
		RestClient client = null;
		try {
			final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
			credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("userid", "password"));
			client = RestClient.builder(new HttpHost("elasticHost", Integer.parseInt("9200")))
					.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
						// Customize connection as per requirement
						public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
							return httpClientBuilder
									// Credentials
									.setDefaultCredentialsProvider(credentialsProvider)
									// Proxy
									.setProxy(new HttpHost("proxyServer", 8080));

						}
					}).setMaxRetryTimeoutMillis(60000).build();

		} catch (Exception ex) {
			ex.printStackTrace();
		}
		return client;
	}

	// Close Open connection
	private static void closeConnnection(RestClient client) {
		if (client != null) {
			try {
				client.close();
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
	}

}

Index Info Object where JSON index detail will map

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;

@JsonIgnoreProperties(ignoreUnknown = true)
public class IndexInfo {
@JsonProperty(value = "health")
private String health;
@JsonProperty(value = "index")
private String indexName;
@JsonProperty(value = "status")
private String status;
@JsonProperty(value = "pri")
private int shards;
@JsonProperty(value = "rep")
private int replica;
@JsonProperty(value = "pri.store.size")
private String dataSize;
@JsonProperty(value = "store.size")
private String totalDataSize;
@JsonProperty(value = "docs.count")
private String documentCount;

@Override
public String toString()
{
	StringBuffer str=new StringBuffer(60);
	str.append("{\n");
	str.append("    \"").append("indexName").append("\":\"").append(indexName).append("\",\n");
	str.append("    \"").append("health").append("\":\"").append(health).append("\",\n");
	str.append("    \"").append("status").append("\":\"").append(status).append("\",\n");
	str.append("    \"").append("shards").append("\":\"").append(shards).append("\",\n");
	str.append("    \"").append("replica").append("\":\"").append(replica).append("\",\n");
	str.append("    \"").append("dataSize").append("\":\"").append(dataSize).append("\",\n");
	str.append("    \"").append("totalDataSize").append("\":\"").append(totalDataSize).append("\",\n");
	str.append("    \"").append("documentCount").append("\":\"").append(documentCount).append("\"\n");
	str.append("    \"");
	return str.toString();
}
public String getIndexName() {
	return indexName;
}
public void setIndexName(String indexName) {
	this.indexName = indexName;
}
public int getShards() {
	return shards;
}
public void setShards(int shards) {
	this.shards = shards;
}
public int getReplica() {
	return replica;
}
public void setReplica(int replica) {
	this.replica = replica;
}
public String getDataSize() {
	return dataSize;
}
public void setDataSize(String dataSize) {
	this.dataSize = dataSize;
}
public String getTotalDataSize() {
	return totalDataSize;
}
public void setTotalDataSize(String totalDataSize) {
	this.totalDataSize = totalDataSize;
}
public String getDocumentCount() {
	return documentCount;
}
public void setDocumentCount(String documentCount) {
	this.documentCount = documentCount;
}
public String getStatus() {
	return status;
}
public void setStatus(String status) {
	this.status = status;
}
public String getHealth() {
	return health;
}
public void setHealth(String health) {
	this.health = health;
}
}

Read More on Elasticsearch REST

Integration

Integrate Filebeat, Kafka, Logstash, Elasticsearch and Kibana

Advertisements

Elasticsearch REST Synchronous and Asynchronous performRequest APIs


Rest client can perform Synchronous and Asynchronous both type of requests. Synchronous Api’s return response with response code while Asynchronous api’s return response as void and accept extra argument extraResponseListener as callback which respond on completion and failure.

Synchronous  performRequest

Response performRequest(String method, String endpoint, Header... headers) throws IOException;

Response performRequest(String method, String endpoint, Map<String, String> params, Header... headers) throws IOException;

Response performRequest(String method, String endpoint, Map<String, String> params, HttpEntity entity, Header... headers) throws IOException;

Response performRequest(String method, String endpoint, Map<String, String> params, HttpEntity entity, HttpAsyncResponseConsumerFactory responseConsumerFactory, Header... headers) throws IOException;

Asynchronous  performRequest

void performRequestAsync(String method, String endpoint, ResponseListener responseListener, Header... headers);

void performRequestAsync(String method, String endpoint, Map<String, String> params, ResponseListener responseListener, Header... headers);

void performRequestAsync(String method, String endpoint, Map<String, String> params, HttpEntity entity, ResponseListener responseListener, Header... headers);

void performRequestAsync(String method, String endpoint, Map<String, String> params, HttpEntity entity, HttpAsyncResponseConsumerFactory responseConsumerFactory, ResponseListener responseListener, Header... headers);

Details about Parameters:

Method :  Elasticsearch support all rest opration like GET, POST,PUT,DELETE.
Endpoint: Url to call elasticsearch apis like (/_cat/indices for getting list of indexes on elasticsearch).
Params: This field is optional and will pass as query strings parameter.
Entity: This field is optional and will pass in method type like POST,PUT or filter query request.
Headers: This is optional will pass if request need header param.

Additional Parameter for Asynchronous call:

ResponseConsumerFactory: Optional and will use to create HttpAsynchResponseConsumer for callback response for request.

ResponseListener: Listener return callback response as request was complete successfully or failure.

Read More on Elasticsearch REST

Integration

Integrate Filebeat, Kafka, Logstash, Elasticsearch and Kibana