介绍
记录将elasticsearch集成到spring boot的过程，以及一些简单的应用和helper类使用。
接入方式
使用spring-boot中的spring-data-elasticsearch,可以使用两种内置客户端接入
1、节点客户端(node client)：
配置文件中设置为local:false,节点客户端以无数据节点(node-master或node-client)身份加入集群，换言之，它自己不存储任何数据，但是它知道数据在集群中的具体位置，并且能够直接转发请求到对应的节点上。
2、传输客户端(Transport client)：
配置文件中设置为local:true,这个更轻量的传输客户端能够发送请求到远程集群。它自己不加入集群，只是简单转发请求给集群中的节点。
两个Java客户端都通过9300端口与集群交互，使用Elasticsearch传输协议(Elasticsearch Transport Protocol)。集群中的节点之间也通过9300端口进行通信。如果此端口未开放，你的节点将不能组成集群。
环境
版本兼容
请一定注意版本兼容问题。这关系到很多maven依赖。Spring Data Elasticsearch Spring Boot version matrix
搭建环境
Spring boot: 1.4.1.RELEASE
spring-data-elasticsearch: 用了最基础的spring-boot-starter-data-elasticsearch，选择高版本时需要对于提高es服务版本
elasticsearch: 2.3.0
Maven依赖
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.1.RELEASE</version> <relativePath/> <!-- lookup parent from repository --></parent><dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-elasticsearch</artifactId> </dependency>
配置文件
bootstrap.yml
spring: data: elasticsearch: # 集群名 cluster-name: syncwt-es # 连接节点,注意在集群中通信都是9300端口，否则会报错无法连接上！ cluster-nodes: localhost:9300,119.29.38.169:9300 # 是否本地连接 local: false repositories: # 仓库中数据存储 enabled: true
调试
启动
启动项目，日志出现以下说明代表成功。并且没有报错。
知识点
在Elasticsearch中，文档归属于一种类型(type),而这些类型存在于索引(index)中，我们可以画一些简单的对比图来类比传统关系型数据库：
Elasticsearch集群可以包含多个索引(indices)（数据库），每一个索引可以包含多个类型(types)（表），每一个类型包含多个文档(documents)（行），然后每个文档包含多个字段(Fields)（列）
Relational DB -> Databases -> Tables -> Rows -> ColumnsElasticsearch -> Indices -> Types -> Documents -> Fields
Demo
Customer.java
/* * Copyright 2012-2013 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.syncwt.www.common.es;import org.springframework.data.annotation.Id;import org.springframework.data.elasticsearch.annotations.Document;@Document(indexName = "es-customer", type = "customer", shards = 2, replicas = 1, 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 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); }}CustomerRepository.java
/* * Copyright 2012-2013 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.syncwt.www.common.es;import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;import java.util.List;public interface CustomerRepository extends ElasticsearchRepository<Customer, String> { public List<Customer> findByFirstName(String firstName); public List<Customer> findByLastName(String lastName);}CustomerController.java
package com.syncwt.www.web;import com.syncwt.www.response.Message;import com.syncwt.www.service.CustomerService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RestController;import java.io.IOException;/** * @version v0.0.1 * @Description CustomerController * @Creation Date 2017年03月30日 下午8:21 * @ModificationHistory Who When What * -------- ---------- ----------------------------------- */@RestControllerpublic class CustomerController { @Autowired private CustomerService customerService; @RequestMapping(value = "/test", method = RequestMethod.GET) public Message test() throws IOException { customerService.saveCustomers(); customerService.fetchAllCustomers(); customerService.fetchIndividualCustomers(); return Message.SUCCESS; }}CustomerService.java
package com.syncwt.www.service;import com.syncwt.www.common.es.Customer;import com.syncwt.www.common.es.CustomerRepository;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.io.IOException;/** * @version v0.0.1 * @Description 业务层 * @Creation Date 2017年03月30日 下午8:19 * @ModificationHistory Who When What * -------- ---------- ----------------------------------- */@Servicepublic class CustomerService { @Autowired private CustomerRepository repository; public void saveCustomers() throws IOException { repository.save(new Customer("Alice", "Smith")); repository.save(new Customer("Bob", "Smith")); } public void fetchAllCustomers() throws IOException { System.out.println("Customers found with findAll():"); System.out.println("-------------------------------"); for (Customer customer : repository.findAll()) { System.out.println(customer); } } public void fetchIndividualCustomers() { System.out.println("Customer found with findByFirstName('Alice'):"); System.out.println("--------------------------------"); System.out.println(repository.findByFirstName("Alice")); System.out.println("Customers found with findByLastName('Smith'):"); System.out.println("--------------------------------"); for (Customer customer : repository.findByLastName("Smith")) { System.out.println(customer); } }}spring对es的操作方法
spring-data-elasticsearch查询方法的封装
1、封装数据库基本CRUD(创建（Create）、更新（Update）、读取（Retrieve）和删除（Delete）)
public interface CrudRepository<T, ID extends Serializable> extends Repository<T, ID> { <S extends T> S save(S entity); T findOne(ID primaryKey); Iterable<T> findAll(); Long count(); void delete(T entity); boolean exists(ID primaryKey); // … more functionality omitted.}2、分页排序查询
public interface PagingAndSortingRepository<T, ID extends Serializable> extends CrudRepository<T, ID> { Iterable<T> findAll(Sort sort); Page<T> findAll(Pageable pageable);}//Accessing the second page by a page size of 20PagingAndSortingRepository<User, Long> repository = // … get access to a beanPage<User> users = repository.findAll(new PageRequest(1, 20));3、计数
public interface UserRepository extends CrudRepository<User, Long> { Long countByLastname(String lastname);}4、删除
public interface UserRepository extends CrudRepository<User, Long> { Long deleteByLastname(String lastname); List<User> removeByLastname(String lastname);}5、自定义查询方法自动注入
声明一个接口继承Repository<T, ID>
interface PersonRepository extends Repository<Person, Long> { … }接口中自定义方法，在方法名中包含T中字段名
查询关键字包括find…By, read…By, query…By, count…By, and get…By,熟悉直接可以用And and Or连接
interface PersonRepository extends Repository<Person, Long> {List<Person> findByLastname(String lastname);}保证注入了elasticsearch配置
在bootstrap.yml中写入了spring-data-elasticsearch的配置文件将自动注入
注入调用
public class SomeClient { @Autowired private PersonRepository repository; public void doSomething() { List<Person> persons = repository.findByLastname("Matthews"); }}6、支持Java8 Stream查询和sql语句查询
@Query("select u from User u")Stream<User> findAllByCustomQueryAndStream();Stream<User> readAllByFirstnameNotNull();@Query("select u from User u")Stream<User> streamAllPaged(Pageable pageable);try (Stream<User> stream = repository.findAllByCustomQueryAndStream()) { stream.forEach(…);}7、支持异步查询
@AsyncFuture<User> findByFirstname(String firstname); @AsyncCompletableFuture<User> findOneByFirstname(String firstname);@AsyncListenableFuture<User> findOneByLastname(String lastname);
支持原生es JavaAPI
1、NativeSearchQueryBuilder构建查询
@Autowiredprivate ElasticsearchTemplate elasticsearchTemplate;SearchQuery searchQuery = new NativeSearchQueryBuilder() .withQuery(matchAllQuery()) .withFilter(boolFilter().must(termFilter("id", documentId))) .build();Page<SampleEntity> sampleEntities = elasticsearchTemplate.queryForPage(searchQuery,SampleEntity.class);2、利用Scan和Scroll进行大结果集查询
SearchQuery searchQuery = new NativeSearchQueryBuilder() .withQuery(matchAllQuery()) .withIndices("test-index") .withTypes("test-type") .withPageable(new PageRequest(0,1)) .build();String scrollId = elasticsearchTemplate.scan(searchQuery,1000,false);List<SampleEntity> sampleEntities = new ArrayList<SampleEntity>();boolean hasRecords = true;while (hasRecords){ Page<SampleEntity> page = elasticsearchTemplate.scroll(scrollId, 5000L , new ResultsMapper<SampleEntity>() { @Override public Page<SampleEntity> mapResults(SearchResponse response) { List<SampleEntity> chunk = new ArrayList<SampleEntity>(); for(SearchHit searchHit : response.getHits()){ if(response.getHits().getHits().length <= 0) { return null; } SampleEntity user = new SampleEntity(); user.setId(searchHit.getId()); user.setMessage((String)searchHit.getSource().get("message")); chunk.add(user); } return new PageImpl<SampleEntity>(chunk); } }); if(page != null) { sampleEntities.addAll(page.getContent()); hasRecords = page.hasNextPage(); } else{ hasRecords = false; } }}3、获取client实例进行节点操作,可以自行封装Util方法
@Autowiredprivate ElasticsearchTemplate elasticsearchTemplate;public void searchHelper() throws IOException { //节点客户端 // on startup// Node node = nodeBuilder().clusterName("syncwt-es").client(true).node();// Client nodeClient = node.client(); //传输客户端// Settings settings = Settings.settingsBuilder().build();// Client transportClient = TransportClient.builder().settings(settings).build(); Client transportClient = elasticsearchTemplate.getClient(); Customer customer = new Customer("Alice", "Smith"); // instance a json mapper ObjectMapper mapper = new ObjectMapper(); // create once, reuse // generate json String json = mapper.writeValueAsString(customer); System.out.println("--------------------------------jackson mapper"); System.out.println(json); XContentBuilder builder = jsonBuilder() .startObject() .field("firstName", "Alice") .field("latName", "Smith") .endObject(); System.out.println("--------------------------------jsonBuilder"); System.out.println(builder.string()); IndexResponse response = transportClient.prepareIndex("es-customer", "customer") .setSource(jsonBuilder() .startObject() .field("firstName", "Alice") .field("latName", "Smith") .endObject() ) .execute() .actionGet(); System.out.println("--------------------------------response"); System.out.println(response.toString()); // on shutdown// node.close();// nodeClient.close(); transportClient.close(); }总结
4、spring-data-elasticsearch对es有很好的支持，但很多高版本在spring-boot中不是很友好。所以，除了spring-boot自动配置的方法，最好掌握代码动态配置方法。
5、为了操作的便利性,我们往往需要动态索引，因为同一个索引（固定）是无法满足集群中多业务的。所以后续封装一个EsUtil类作为基本操作公交类
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。
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