Spring Data ElasticSearch NullPointerException - spring

Question

I have just started with Spring Data ElasticSearch. I have implemented my own repository, but I get a null pointer exception if I try to save an entity. I have got the following code, this is only some test code.
package org.test.elasticsearch.models;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
#Document(indexName = "test", type = "book", shards = 1, replicas = 0)
public class Book {
#Id
private String id;
private String title;
private String author;
public Book(final String id, final String title, final String author) {
this.id = id;
this.title = title;
this.author = author;
}
public String getId() {
return this.id;
}
public void setId(final String id) {
this.id = id;
}
public String getTitle() {
return this.title;
}
public void setTitle(final String title) {
this.title = title;
}
public String getAuthor() {
return this.author;
}
public void setAuthor(final String author) {
this.author = author;
}
}
package org.test.elasticsearch.configs;
import org.elasticsearch.node.NodeBuilder;
import org.test.elasticsearch.repositories.implementations.BookRepositoryImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;
#Configuration
#EnableElasticsearchRepositories("org.test.elasticsearch.repositories")
public class ElasticsearchConfiguration {
#Bean
public ElasticsearchOperations elasticsearchTemplate() {
final NodeBuilder nodeBuilder = new NodeBuilder();
return new ElasticsearchTemplate(nodeBuilder.local(true).clusterName("elasticsearch").node().client());
}
#Bean
public BookRepositoryImpl bookRepositoryImplementation() {
return new BookRepositoryImpl();
}
}
package org.test.elasticsearch.repositories;
import org.test.elasticsearch.models.Book;
import org.springframework.data.elasticsearch.repository.ElasticsearchCrudRepository;
public interface BookRepository extends ElasticsearchCrudRepository<Book, String>, BookRepositoryCustom {
// query methods
}
package org.test.webapp;
import org.test.elasticsearch.models.Book;
import org.test.elasticsearch.models.Book.BookBuilder;
import org.test.elasticsearch.repositories.BookRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
#Configuration
#ComponentScan
#EnableAutoConfiguration
public class Test {
#Autowired
static BookRepository BookRepository;
public static void main(final String[] args) {
SpringApplication.run(test.class, args);
final Book testBook = new Book("12345", "TestTitle", "TestAuthor");
BookRepository.save(testBook);
}
}
That's my code. And I get the following message after running my spring boot application.
Exception in thread "main" java.lang.NullPointerException
at org.test.webapp.test.main(Test.java:24)
Does anyone have an idea? And another question: When should I use ElasticsearchTemplate with IndexQuery over a custom repository to save my entities?

Answer 1

Your problem is, actually, with Spring Boot: you are not using it properly. Your Test class should look like this (no "static" access to BookRepository and done differently):
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.test.elasticsearch.models.Book;
import org.test.elasticsearch.repositories.BookRepository;
#Configuration
#ComponentScan(basePackages = {"org.test.elasticsearch.configs", "org.test.webapp"})
#EnableAutoConfiguration
public class Test implements CommandLineRunner {
#Autowired
private BookRepository bookRepository;
#Override
public void run(String... args) {
final Book testBook = new Book("12345", "TestTitle", "TestAuthor");
bookRepository.save(testBook);
}
public static void main(final String[] args) {
SpringApplication.run(Test.class, args);
}
}
Because, as I see it, you don't want to use a web application, so further you only need these dependencies in pom.xml. Nothing related to spring-boot-web:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-elasticsearch</artifactId>
<version>1.0.0.RELEASE</version>
</dependency>