一、简介
springboot 连接 elasticsearch，主流的方式有以下四种方式
方式一：通过Elastic Transport Client客户端连接 es 服务器，底层基于 TCP 协议通过 transport 模块和远程 ES 服务端通信，不过，从 V7.0 开始官方不建议使用，V8.0开始正式移除。
方式二：通过Elastic Java Low Level Rest Client客户端连接 es 服务器，底层基于 HTTP 协议通过 restful API 来和远程 ES 服务端通信，只提供了最简单最基本的 API，类似于上篇文章中给大家介绍的 API 操作逻辑。
方式三：通过Elastic Java High Level Rest Client客户端连接 es 服务器，底层基于Elastic Java Low Level Rest Client客户端做了一层封装，提供了更高级得 API 且和Elastic Transport Client接口及参数保持一致，官方推荐的 es 客户端。
方式四：通过JestClient客户端连接 es 服务器，这是开源社区基于 HTTP 协议开发的一款 es 客户端，官方宣称接口及代码设计比 ES 官方提供的 Rest 客户端更简洁、更合理，更好用，具有一定的 ES 服务端版本兼容性，但是更新速度不是很快，目前 ES 版本已经出到 V7.9，但是JestClient只支持 V1.0~V6.X 版 本的 ES。
还有一个需要大家注意的地方，那就是版本号的兼容！
在开发过程中，大家尤其需要关注一下客户端和服务端的版本号，要尽可能保持一致，比如服务端 es 的版本号是6.8.2，那么连接 es 的客户端版本号，最好也是6.8.2，即使因项目的原因不能保持一致，客户端的版本号必须在6.0.0 ～6.8.2，不要超过服务器的版本号，这样客户端才能保持正常工作，否则会出现很多意想不到的问题，假如客户端是7.0.4的版本号，此时的程序会各种报错，甚至没办法用!
为什么要这样做呢?主要原因就是 es 的服务端，高版本不兼容低版本;es6 和 es7 的某些 API 请求参数结构有着很大的区别，所以客户端和服务端版本号尽量保持一致。
废话也不多说了，直接上代码!
二、代码实践
本文采用的SpringBoot版本号是2.1.0.RELEASE，服务端 es 的版本号是6.8.2，客户端采用的是官方推荐的Elastic Java High Level Rest Client版本号是6.4.2，方便与SpringBoot的版本兼容。
2.1、导入依赖
<!--elasticsearch-->
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>6.4.2</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>6.4.2</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.4.2</version>
</dependency>2.2、配置环境变量
在application.properties全局配置文件中，配置elasticsearch自定义环境变量。
elasticsearch.scheme=http elasticsearch.address=127.0.0.1:9200 elasticsearch.userName= elasticsearch.userPwd= elasticsearch.socketTimeout=5000 elasticsearch.connectTimeout=5000 elasticsearch.connectionRequestTimeout=5000
2.3、创建 elasticsearch 的 config 类
@Configuration
public class ElasticsearchConfiguration {
private static final Logger log = LoggerFactory.getLogger(ElasticsearchConfiguration.class);
private static final int ADDRESS_LENGTH = 2;
@Value("${elasticsearch.scheme:http}")
private String scheme;
@Value("${elasticsearch.address}")
private String address;
@Value("${elasticsearch.userName}")
private String userName;
@Value("${elasticsearch.userPwd}")
private String userPwd;
@Value("${elasticsearch.socketTimeout:5000}")
private Integer socketTimeout;
@Value("${elasticsearch.connectTimeout:5000}")
private Integer connectTimeout;
@Value("${elasticsearch.connectionRequestTimeout:5000}")
private Integer connectionRequestTimeout;
/**
* 初始化客户端
* @return
*/
@Bean(name = "restHighLevelClient")
public RestHighLevelClient restClientBuilder() {
HttpHost[] hosts = Arrays.stream(address.split(","))
.map(this::buildHttpHost)
.filter(Objects::nonNull)
.toArray(HttpHost[]::new);
RestClientBuilder restClientBuilder = RestClient.builder(hosts);
// 异步参数配置
restClientBuilder.setHttpClientConfigCallback(httpClientBuilder -> {
httpClientBuilder.setDefaultCredentialsProvider(buildCredentialsProvider());
return httpClientBuilder;
});
// 异步连接延时配置
restClientBuilder.setRequestConfigCallback(requestConfigBuilder -> {
requestConfigBuilder.setConnectionRequestTimeout(connectionRequestTimeout);
requestConfigBuilder.setSocketTimeout(socketTimeout);
requestConfigBuilder.setConnectTimeout(connectTimeout);
return requestConfigBuilder;
});
return new RestHighLevelClient(restClientBuilder);
}
/**
* 根据配置创建HttpHost
* @param s
* @return
*/
private HttpHost buildHttpHost(String s) {
String[] address = s.split(":");
if (address.length == ADDRESS_LENGTH) {
String ip = address[0];
int port = Integer.parseInt(address[1]);
return new HttpHost(ip, port, scheme);
} else {
return null;
}
}
/**
* 构建认证服务
* @return
*/
private CredentialsProvider buildCredentialsProvider(){
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(userName,
userPwd));
return credentialsProvider;
}
}至此，客户端配置完毕，项目启动的时候，会自动注入到Spring的ioc容器里面。
2.4、索引管理
es 中最重要的就是索引库，客户端如何创建呢?请看下文！
创建索引
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 创建索引（简单模式）
* @throws IOException
*/
@Test
public void createIndex() throws IOException {
CreateIndexRequest request = new CreateIndexRequest("cs_index");
CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
System.out.println(response.isAcknowledged());
}
/**
* 创建索引（复杂模式）
* 可以直接把对应的文档结构也一并初始化
* @throws IOException
*/
@Test
public void createIndexComplete() throws IOException {
CreateIndexRequest request = new CreateIndexRequest();
//索引名称
request.index("cs_index");
//索引配置
Settings settings = Settings.builder()
.put("index.number_of_shards", 3)
.put("index.number_of_replicas", 1)
.build();
request.settings(settings);
//映射结构字段
Map<String, Object> properties = new HashMap();
properties.put("id", ImmutableBiMap.of("type", "text"));
properties.put("name", ImmutableBiMap.of("type", "text"));
properties.put("sex", ImmutableBiMap.of("type", "text"));
properties.put("age", ImmutableBiMap.of("type", "long"));
properties.put("city", ImmutableBiMap.of("type", "text"));
properties.put("createTime", ImmutableBiMap.of("type", "long"));
Map<String, Object> mapping = new HashMap<>();
mapping.put("properties", properties);
//添加一个默认类型
System.out.println(JSON.toJSONString(request));
request.mapping("_doc",mapping);
CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
System.out.println(response.isAcknowledged());
}
}删除索引
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 删除索引
* @throws IOException
*/
@Test
public void deleteIndex() throws IOException {
DeleteIndexRequest request = new DeleteIndexRequest("cs_index1");
AcknowledgedResponse response = client.indices().delete(request, RequestOptions.DEFAULT);
System.out.println(response.isAcknowledged());
}
}查询索引
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 查询索引
* @throws IOException
*/
@Test
public void getIndex() throws IOException {
// 创建请求
GetIndexRequest request = new GetIndexRequest();
request.indices("cs_index");
// 执行请求,获取响应
GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}查询索引是否存在
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 检查索引是否存在
* @throws IOException
*/
@Test
public void exists() throws IOException {
// 创建请求
GetIndexRequest request = new GetIndexRequest();
request.indices("cs_index");
// 执行请求,获取响应
boolean response = client.indices().exists(request, RequestOptions.DEFAULT);
System.out.println(response);
}
}查询所有的索引名称
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 查询所有的索引名称
* @throws IOException
*/
@Test
public void getAllIndices() throws IOException {
GetAliasesRequest request = new GetAliasesRequest();
GetAliasesResponse response = client.indices().getAlias(request,RequestOptions.DEFAULT);
Map<String, Set<AliasMetaData>> map = response.getAliases();
Set<String> indices = map.keySet();
for (String key : indices) {
System.out.println(key);
}
}
}查询索引映射字段
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 查询索引映射字段
* @throws IOException
*/
@Test
public void getMapping() throws IOException {
GetMappingsRequest request = new GetMappingsRequest();
request.indices("cs_index");
request.types("_doc");
GetMappingsResponse response = client.indices().getMapping(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}添加索引映射字段
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class IndexJunit {
@Autowired
private RestHighLevelClient client;
/**
* 添加索引映射字段
* @throws IOException
*/
@Test
public void addMapping() throws IOException {
PutMappingRequest request = new PutMappingRequest();
request.indices("cs_index");
request.type("_doc");
//添加字段
Map<String, Object> properties = new HashMap();
properties.put("accountName", ImmutableBiMap.of("type", "keyword"));
Map<String, Object> mapping = new HashMap<>();
mapping.put("properties", properties);
request.source(mapping);
PutMappingResponse response = client.indices().putMapping(request, RequestOptions.DEFAULT);
System.out.println(response.isAcknowledged());
}
}2.5、文档管理
所谓文档，就是向索引里面添加数据，方便进行数据查询，详细操作内容，请看下文！
添加文档
ublic class UserDocument {
private String id;
private String name;
private String sex;
private Integer age;
private String city;
private Date createTime;
//省略get、set...
}@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 添加文档
* @throws IOException
*/
@Test
public void addDocument() throws IOException {
// 创建对象
UserDocument user = new UserDocument();
user.setId("1");
user.setName("里斯");
user.setCity("武汉");
user.setSex("男");
user.setAge(20);
user.setCreateTime(new Date());
// 创建索引,即获取索引
IndexRequest request = new IndexRequest();
// 外层参数
request.id("1");
request.index("cs_index");
request.type("_doc");
request.timeout(TimeValue.timeValueSeconds(1));
// 存入对象
request.source(JSON.toJSONString(user), XContentType.JSON);
// 发送请求
System.out.println(request.toString());
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}更新文档
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 更新文档（按需修改）
* @throws IOException
*/
@Test
public void updateDocument() throws IOException {
// 创建对象
UserDocument user = new UserDocument();
user.setId("2");
user.setName("程咬金");
user.setCreateTime(new Date());
// 创建索引,即获取索引
UpdateRequest request = new UpdateRequest();
// 外层参数
request.id("2");
request.index("cs_index");
request.type("_doc");
request.timeout(TimeValue.timeValueSeconds(1));
// 存入对象
request.doc(JSON.toJSONString(user), XContentType.JSON);
// 发送请求
System.out.println(request.toString());
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}删除文档
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 删除文档
* @throws IOException
*/
@Test
public void deleteDocument() throws IOException {
// 创建索引,即获取索引
DeleteRequest request = new DeleteRequest();
// 外层参数
request.id("1");
request.index("cs_index");
request.type("_doc");
request.timeout(TimeValue.timeValueSeconds(1));
// 发送请求
System.out.println(request.toString());
DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}查询文档是不是存在
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 查询文档是不是存在
* @throws IOException
*/
@Test
public void exists() throws IOException {
// 创建索引,即获取索引
GetRequest request = new GetRequest();
// 外层参数
request.id("3");
request.index("cs_index");
request.type("_doc");
// 发送请求
System.out.println(request.toString());
boolean response = client.exists(request, RequestOptions.DEFAULT);
System.out.println(response);
}
}通过 ID 查询指定文档
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 通过ID，查询指定文档
* @throws IOException
*/
@Test
public void getById() throws IOException {
// 创建索引,即获取索引
GetRequest request = new GetRequest();
// 外层参数
request.id("1");
request.index("cs_index");
request.type("_doc");
// 发送请求
System.out.println(request.toString());
GetResponse response = client.get(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
}
}批量添加文档
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class DocJunit {
@Autowired
private RestHighLevelClient client;
/**
* 批量添加文档
* @throws IOException
*/
@Test
public void batchAddDocument() throws IOException {
// 批量请求
BulkRequest bulkRequest = new BulkRequest();
bulkRequest.timeout(TimeValue.timeValueSeconds(10));
// 创建对象
List<UserDocument> userArrayList = new ArrayList<>();
userArrayList.add(new UserDocument("张三", "男", 30, "武汉"));
userArrayList.add(new UserDocument("里斯", "女", 31, "北京"));
userArrayList.add(new UserDocument("王五", "男", 32, "武汉"));
userArrayList.add(new UserDocument("赵六", "女", 33, "长沙"));
userArrayList.add(new UserDocument("七七", "男", 34, "武汉"));
// 添加请求
for (int i = 0; i < userArrayList.size(); i++) {
userArrayList.get(i).setId(String.valueOf(i));
IndexRequest indexRequest = new IndexRequest();
// 外层参数
indexRequest.id(String.valueOf(i));
indexRequest.index("cs_index");
indexRequest.type("_doc");
indexRequest.timeout(TimeValue.timeValueSeconds(1));
indexRequest.source(JSON.toJSONString(userArrayList.get(i)), XContentType.JSON);
bulkRequest.add(indexRequest);
}
// 执行请求
BulkResponse response = client.bulk(bulkRequest, RequestOptions.DEFAULT);
System.out.println(response.status());
}
} 
