Spring data: ArangoDB: CollectionOperations: Create hash index for the collection

CollectionOperations interface provides 'ensureHashIndex' method to create a hash index for the collection if it does not already exist. Query by example queries use this index.

 

Signature

IndexEntity ensureHashIndex(Iterable<String> fields, HashIndexOptions options) throws DataAccessException;

 

‘HashIndexOptions’ is used to provide additional options which are used while creating the index. Below table summarizes possible options associated with HashIndexOptions.

 

Option	Data type	Description
inBackground	Boolean	create the the index in the background
name	String	name of the index
fields	Iterable<String>	list of attribute paths like a, a.b, a.b.c etc.,
type	IndexType	IndexType is an enum and can be one of a.   primary, b.   hash, c.    skiplist, d.   persistent, e.   geo, f.     geo1, g.   geo2, h.   fulltext, i.     edge, j.     ttl
unique	Boolean	if true, then create a unique index
sparse	Boolean	if true, then create a sparse index
deduplicate	Boolean	if false, the deduplication of array values is turned off.

 

Example

HashIndexOptions hashIndexOptions = new HashIndexOptions();
hashIndexOptions.name("nameIndex");

empsCollection.ensureHashIndex(Arrays.asList("firstName", "lastName"), hashIndexOptions);

 

Find the below working application.

 

Step 1: Create new maven project ‘collection-operations-create-hash-index’.

 

Step 2: Update pom.xml with maven dependencies.

 

pom.xml

 

<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>
	<groupId>com.sample.app</groupId>
	<artifactId>collection-operations-create-hash-index</artifactId>
	<version>1</version>

	<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-parent -->
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.5</version>
	</parent>


	<dependencies>
		<dependency>
			<groupId>com.arangodb</groupId>
			<artifactId>arangodb-spring-boot-starter</artifactId>
			<version>2.3.3.RELEASE</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

 

Step 3: Define entity class.

 

Employee.java

package com.sample.app.entity;

import com.arangodb.springframework.annotation.ArangoId;
import com.arangodb.springframework.annotation.Document;
import org.springframework.data.annotation.Id;

@Document("employees")
public class Employee {

    @Id // db document field: _key
    private String key;

    @ArangoId // db document field: _id
    private String arangoId;

    private Integer id;
    private String firstName;
    private String lastName;
    private Integer age;

    public Employee(Integer id, String firstName, String lastName, Integer age) {
        super();
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.age = age;
    }

    public Employee() {
        
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getArangoId() {
        return arangoId;
    }

    public void setArangoId(String arangoId) {
        this.arangoId = arangoId;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Employee [key=" + key + ", arangoId=" + arangoId + ", id=" + id + ", firstName=" + firstName
                + ", lastName=" + lastName + ", age=" + age + "]";
    }

}

Step 4: Define arango configuration class.

 

ArangoConfig.java

package com.sample.app.config;

import org.springframework.context.annotation.Configuration;

import com.arangodb.ArangoDB;
import com.arangodb.springframework.annotation.EnableArangoRepositories;
import com.arangodb.springframework.config.ArangoConfiguration;

@Configuration
@EnableArangoRepositories(basePackages = { "com.sample.app" })
public class ArangoConfig implements ArangoConfiguration {

    @Override
    public ArangoDB.Builder arango() {
        return new ArangoDB.Builder().host("localhost", 8529).user("root").password("tiger");
    }

    @Override
    public String database() {
        return "abc_org";
    }
}

Step 5: Define main application class.

 

App.java

package com.sample.app;

import java.util.Arrays;
import java.util.Collection;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import com.arangodb.entity.IndexEntity;
import com.arangodb.model.HashIndexOptions;
import com.arangodb.springframework.core.ArangoOperations;
import com.arangodb.springframework.core.CollectionOperations;
import com.sample.app.entity.Employee;

@SpringBootApplication
public class App {

	@Autowired
	private ArangoOperations arangoTemplate;

	public static void main(String args[]) {
		SpringApplication.run(App.class, args);
	}

	@Bean
	public CommandLineRunner demo() {

		return (args) -> {
			Employee emp1 = new Employee(1, "Krishna", "Gurram", 33);
			Employee emp2 = new Employee(2, "Lahari", "G", 20);
			Employee emp3 = new Employee(3, "Thulasi", "G", 19);

			arangoTemplate.insert(Arrays.asList(emp1, emp2, emp3), Employee.class);

			Iterable<Employee> empsIterable = arangoTemplate.findAll(Employee.class);

			System.out.println("Documents in employees collection");
			for (Employee emp : empsIterable) {
				System.out.println(emp);
			}

			CollectionOperations empsCollection = arangoTemplate.collection(Employee.class);

			HashIndexOptions hashIndexOptions = new HashIndexOptions();
			hashIndexOptions.name("nameIndex");

			empsCollection.ensureHashIndex(Arrays.asList("firstName", "lastName"), hashIndexOptions);

			Collection<IndexEntity> indexesCollection = empsCollection.getIndexes();

			System.out.println("\nTotal indexes : " + indexesCollection.size());

			for (IndexEntity indexEntity : indexesCollection) {
				System.out.println("\nindex details");
				System.out.println("name : " + indexEntity.getName());
				System.out.println("Index created on fields : " + indexEntity.getFields());
			}

			System.out.println("\nDropping the collection");

			empsCollection.drop();

		};
	}
}

Total project structure looks like below.

Run App.java, you will see below messages in console.

Documents in employees collection
Employee [key=51679, arangoId=employees/51679, id=1, firstName=Krishna, lastName=Gurram, age=33]
Employee [key=51680, arangoId=employees/51680, id=2, firstName=Lahari, lastName=G, age=20]
Employee [key=51681, arangoId=employees/51681, id=3, firstName=Thulasi, lastName=G, age=19]

Total indexes : 2

index details
name : primary
Index created on fields : [_key]

index details
name : nameIndex
Index created on fields : [firstName, lastName]

Dropping the collection

You can download complete working application from below link.

https://github.com/harikrishna553/springboot/tree/master/arangodb/collection-operations-create-hash-index

  

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