21 springboot集成elasticsearch

首先安装elasticsearch（自己google）。注意的是：版本不同有各种坑，我这用的是6.X版本
官网下载，然后采用springboot官网上的一个例子。项目地址

配置文件

spring.data.elasticsearch.cluster-nodes=localhost:9300
#下面的按需求去加，可以不加，这就注释掉了，具体的在es配置文件里
#spring.data.elasticsearch.cluster-name=my-application

首先是pom主要文件。

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

然后是bean。

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;

@Document(indexName = "customer", type = "customer", shards = 1, replicas = 0, refreshInterval = "-1")
public class Customer {

    @Id
    private String id;

    private String firstName;

    private String lastName;

    public Customer() {
    }

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public Customer(String id, String firstName, String lastName) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public String getId() {
        return this.id;
    }

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

    public String getFirstName() {
        return this.firstName;
    }

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

    public String getLastName() {
        return this.lastName;
    }

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

    @Override
    public String toString() {
        return String.format("Customer[id=%s, firstName='%s', lastName='%s']", this.id,
                this.firstName, this.lastName);
    }

}

里面的index相当于db，type相当于table。然后就是属性。Id是主键。

操作类，这里是接口继承了ElasticsearchRepository

import java.util.List;

import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

public interface CustomerRepository extends ElasticsearchRepository<Customer, String> {

    public Customer findByFirstName(String firstName);

    public List<Customer> findByLastName(String lastName);

}

最后是启动类和操作

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.core.annotation.Order;


@SpringBootApplication
public class App implements CommandLineRunner {

    @Autowired
    private CustomerRepository repository;

    @Override
    public void run(String... args) throws Exception {
        this.repository.deleteAll();
        saveCustomers();
        fetchAllCustomers();
        fetchIndividualCustomers();
    }

    private void saveCustomers() {
        this.repository.save(new Customer("1","Alice", "Smith"));
        this.repository.save(new Customer("2","Bob", "Smith"));
    }

    private void fetchAllCustomers() {
        System.out.println("Customers found with findAll():");
        System.out.println("==============================");
        for (Customer customer : this.repository.findAll()) {
            System.out.println(customer);
        }
        System.out.println();
    }

    private void fetchIndividualCustomers() {
        System.out.println("Customer found with findByFirstName('Alice'):");
        System.out.println("--------------------------------");
        System.out.println(this.repository.findByFirstName("Alice"));

        System.out.println("Customers found with findByLastName('Smith'):");
        System.out.println("++++++++++++++++++++++++++++++++");
        for (Customer customer : this.repository.findByLastName("Smith")) {
            System.out.println(customer);
        }
    }

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

上面的实现了CommandLineRunner，这个接口目的就是springboot加载之后就会执行这个接口的方法。
代码中注入了CustomerRepository，然后以这个去操作es。最后得到的结果是

说明已经连接上es，并插入和查询成功。
这里面只继承了一个ElasticsearchRepository，然后用这个去做操作就行。最简单的的demo就好了