Tag Archives: Health

java.lang.Short Class & Methods


The java.lang.Short class wraps a value of primitive type short in an object. An object of type Short contains a single field whose type is short. This class provides several utility methods for converting a short to a String and a String to a short, as well as other constants and methods useful when dealing with a short.

Short class implements Comparable Interface that’s help while sorting list of Objects on natural order.

See Also:

Constants

  • static short MAX_VALUE :A constant holding the maximum value a short can have, 215-1.
  • static short MIN_VALUE :A constant holding the minimum value a short can have, -215.
  • static int SIZE :The number of bits used to represent a short value in two’s complement binary form.
  • static Class TYPE :The Class instance representing the primitive type short.

Constructors

  • Short(short value) :Constructs a newly allocated Short object that represents the specified short value.
  • Short(String s) :Constructs a newly allocated Short object that represents the short value indicated by the String parameter.

Methods

  • byte byteValue() :Returns the value of this Short as a byte.
  • static int compare(short x, short y) :Compares two short values numerically.
  • int compareTo(Short anotherShort) :Compares two Short objects numerically.
  • static Short decode(String nm) :Decodes a String into a Short.
  • double doubleValue() :Returns the value of this Short as a double.
  • boolean equals(Object obj) :Compares this object to the specified object.
  • float floatValue() :Returns the value of this Short as a float.
  • int hashCode() :Returns a hash code for this Short; equal to the result of invoking intValue().
  • int intValue() :Returns the value of this Short as an int.
  • long longValue() :Returns the value of this Short as a long.
  • static short parseShort(String s) :Parses the string argument as a signed decimal short.
  • static short parseShort(String s, int radix) :Parses the string argument as a signed short in the radix specified by the second argument.
  • static short reverseBytes(short i) :Returns the value obtained by reversing the order of the bytes in the two’s complement representation of the specified short value.
  • short shortValue() :Returns the value of this Short as a short.
  • String toString() :Returns a String object representing this Short’s value.
  • String toString(short s) :Returns a new String object representing the specified short.
  • static Short valueOf(short s) :Returns a Short instance representing the specified short value.
  • static Short valueOf(String s) :Returns a Short object holding the value given by the specified String.
  • static Short valueOf(String s, int radix) :Returns a Short object holding the value extracted from the specified String when parsed with the radix given by the second argument.

Exceptions

References

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Elasticsearch REST JAVA Client for Cluster Detail


Below is example to get Cluster Detail in Java Object by using Elasticsearch REST Java client. Here client will call endpoint  “/_cluster/health” to retrieve all detail of index list. It is same as we use GET by CURL

GET http://elasticsearchHost:9200/_cluster/health

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 ElasticsearchRESTClusterClient {

	public static void main(String[] args) {
		ClusterInfo clusterHealth = null;
		RestClient client = null;
		try {
			client = openConnection();
			if (client != null) {
				// performRequest GET method will retrieve all cluster health
				// information from elastic server
				Response response = client.performRequest("GET", "/_cluster/health",
						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 ClusterInfo
				// Cluster Info
				clusterHealth = jacksonObjectMapper.readValue(entity.getContent(), ClusterInfo.class);
				System.out.println(clusterHealth);
			}

		} 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();
			}
		}
	}

}

Cluster Info Java Object where retrieve json response will map.

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

@JsonIgnoreProperties(ignoreUnknown = true)
public class ClusterInfo {

@JsonProperty(value = "cluster_name")
private String clusterName;
@JsonProperty(value = "status")
private String clusterStatus;
@JsonProperty(value = "active_primary_shards")
private int primaryActiveShards;
@JsonProperty(value = "active_shards")
private int activeShards;
@JsonProperty(value = "delayed_unassigned_shards")
private int delayedUnAssignedShards;
@JsonProperty(value = "unassigned_shards")
private int unAssignedShards;
@JsonProperty(value = "initializing_shards")
private int initializingShards;
@JsonProperty(value = "relocating_shards")
private int relocatingShards;
@JsonProperty(value = "number_of_nodes")
private int totalNodeCount;
@JsonProperty(value = "number_of_data_nodes")
private int dataNodeCount;

@Override
public String toString()
{
	StringBuffer str=new StringBuffer(60);
	str.append("{\n");
	str.append("    \"").append("clusterName").append("\":\"").append(clusterName).append("\",\n");
	str.append("    \"").append("clusterStatus").append("\":\"").append(clusterStatus).append("\",\n");
	str.append("    \"").append("primaryActiveShards").append("\":\"").append(primaryActiveShards).append("\",\n");
	str.append("    \"").append("activeShards").append("\":\"").append(activeShards).append("\",\n");
	str.append("    \"").append("delayedUnAssignedShards").append("\":\"").append(delayedUnAssignedShards).append("\",\n");
	str.append("    \"").append("unAssignedShards").append("\":\"").append(unAssignedShards).append("\",\n");
	str.append("    \"").append("initializingShards").append("\":\"").append(initializingShards).append("\",\n");
	str.append("    \"").append("relocatingShards").append("\":\"").append(relocatingShards).append("\",\n");
	str.append("    \"").append("totalNodeCount").append("\":\"").append(totalNodeCount).append("\",\n");
	str.append("    \"").append("dataNode").append("\":\"").append(dataNodeCount).append("\"");
	str.append("    \"");
	return str.toString();
}

public String getClusterName() {
	return clusterName;
}
public void setClusterName(String clusterName) {
	this.clusterName = clusterName;
}
public String getClusterStatus() {
	return clusterStatus;
}
public void setClusterStatus(String clusterStatus) {
	this.clusterStatus = clusterStatus;
}
public int getPrimaryActiveShards() {
	return primaryActiveShards;
}
public void setPrimaryActiveShards(int primaryActiveShards) {
	this.primaryActiveShards = primaryActiveShards;
}
public int getActiveShards() {
	return activeShards;
}
public void setActiveShards(int activeShards) {
	this.activeShards = activeShards;
}
public int getDelayedUnAssignedShards() {
	return delayedUnAssignedShards;
}
public void setDelayedUnAssignedShards(int delayedUnAssignedShards) {
	this.delayedUnAssignedShards = delayedUnAssignedShards;
}
public int getUnAssignedShards() {
	return unAssignedShards;
}
public void setUnAssignedShards(int unAssignedShards) {
	this.unAssignedShards = unAssignedShards;
}
public int getInitializingShards() {
	return initializingShards;
}
public void setInitializingShards(int initializingShards) {
	this.initializingShards = initializingShards;
}
public int getRelocatingShards() {
	return relocatingShards;
}
public void setRelocatingShards(int relocatingShards) {
	this.relocatingShards = relocatingShards;
}
public int getDataNodeCount() {
	return dataNodeCount;
}
public void setDataNodeCount(int dataNodeCount) {
	this.dataNodeCount = dataNodeCount;
}
public int getTotalNodeCount() {
	return totalNodeCount;
}
public void setTotalNodeCount(int totalNodeCount) {
	this.totalNodeCount = totalNodeCount;
}
}

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