项目搭建
老规矩，先建maven项目,下面是我的pom.xml
4.0.0 org.example springboot-es-all 1.0-SNAPSHOT 1.8 org.springframework.boot spring-boot-starter-parent 2.1.3.RELEASE org.springframework.boot spring-boot-starter-test org.elasticsearch.client elasticsearch-rest-client 7.8.0 org.elasticsearch elasticsearch 7.8.0 org.elasticsearch.client elasticsearch-rest-high-level-client 7.8.0 cn.hutool hutool-all 5.8.4 com.alibaba fastjson 1.2.58 org.slf4j slf4j-api 1.6.4 org.slf4j slf4j-simple 1.7.25 compile org.projectlombok lombok org.springframework.boot spring-boot-maven-plugin 2.1.3.RELEASE
这里我使用的是elasticsearch-rest-high-level-client官方客户端,建议大家尽量用官方的，因为随着es的不断升级，很多api都过时了，如果你使用spring-boot-starter-data-elasticsearch这个要依赖社区去维护,很多新特性你没法使用到,也会存在安全性问题。
配置客户端
启动类:
@SpringBootApplication
public class EsStudyApplication {
public static void main(String[] args) {
SpringApplication.run(EsStudyApplication.class, args);
}
}配置文件 application.yml:
server: port: 9000 elasticsearch: host: 0.0.0.0 port: 9200 username: password:
客户端配置 config.EsClientConfig:
@Configuration
public class EsClientConfig {
@Value("${elasticsearch.host}")
private String host;
@Value("${elasticsearch.port}")
private int port;
@Value("${elasticsearch.username}")
private String userName;
@Value("${elasticsearch.password}")
private String password;
@Bean
public RestHighLevelClient restHighLevelClient() {
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(userName, password));
RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
RestClient.builder(new HttpHost( host, port, "http")).setHttpClientConfigCallback(httpClientBuilder -youjiankuohaophpcn {
httpClientBuilder.setMaxConnTotal(500);
httpClientBuilder.setMaxConnPerRoute(300);
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
})
);
return restHighLevelClient;
}
}然后客户端我们就配好了，客户端的配置其实还有很多，感兴趣的同学自行查阅。后续使用的时候，直接导入RestHighLevelClient实例就好了
接着启动它，如果控制没有报错，说明配置没啥问题了， 记得要开启es服务~
索引API初探 & Index API
下面我们写一点测试用例，来验证我们是否可以操作es，为了方便演示，这里直接使用SpringBootTest来测试，大家平时在写springboot项目，类测试的时候也可以这么做
ping
新建api.IndexApi,调用ping()方法来测试是否链接成功:
@Slf4j
@SpringBootTest
public class IndexApi {
/**
* es 索引
*/
public static final String index = "study";
@Autowired
private RestHighLevelClient client;
@Test
public void ping() throws IOException {
if(client.ping(RequestOptions.DEFAULT)) {
log.info("链接成功");
}else {
log.info("链接失败 !");
}
}
}点击IndexApi左上角的绿色箭头启动测试用例, 如果报错，尝试添加以下 注解
@RunWith(SpringRunner.class)
@SpringBootTest(classes = { EsStudyApplication.class })
public class IndexApi {....}返回:
链接成功
说明客户端与es服务端是通的
创建索引 & create
通过前面的学习，有了一定的基础之后，回到代码中其实就是调调方法，因为你知道了这个代码的逻辑做了什么操作。下面来看下如何创建索引：
/**
* 创建索引
*/
@Test
public void createIndex() throws IOException {
CreateIndexRequest request = new CreateIndexRequest(index);
CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);
log.info("创建索引 ===> "+ JSONObject.toJSONString(createIndexResponse)); // 创建索引 ===> {"acknowledged":true,"fragment":false,"shardsAcknowledged":true}
}大家可以返回到kibana中查看索引是否被创建，从而验证代码执行是否成功
添加别名:
// alias
request.alias(new Alias("study_alias"));索引设置settings:
// index settings
request.settings(
Settings.builder()
.put("index.number_of_shards", 3)
.put("index.number_of_replicas", 2)
);索引映射mapping:
// index mappings
// {
// "mapping": {
// "_doc": {
// "properties": {
// "name": {
// "type": "text"
// }
// }
// }
// }
// }
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
builder.startObject("properties");
{
builder.startObject("name");
{
builder.field("type", "text");
}
builder.endObject();
}
builder.endObject();
}
builder.endObject();
request.mapping(builder);设置请求超时时间:
// 请求设置 request.setTimeout(TimeValue.timeValueMinutes(1));
索引是否存在 & exist
/**
* 判断索引是否存在
* @throws IOException
*/
@Test
public void existIndex() throws IOException {
GetIndexRequest request = new GetIndexRequest(index);
boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
log.info("索引{}存在 ===> {}", index, exists);
}删除索引
/**
* 删除索引
* @throws IOException
*/
@Test
public void delIndex() throws IOException {
DeleteIndexRequest request = new DeleteIndexRequest(index);
AcknowledgedResponse delete = client.indices().delete(request, RequestOptions.DEFAULT);
log.info("删除索引 ===> {}", JSONObject.toJSONString(delete)); // 删除索引 ===> {"acknowledged":true,"fragment":false}
} 
