一、前言：
好久没写笔记了，最近忙一个项目，用到ES查询，以往的笔记写ES都是搭建环境，用Kibana玩一玩
这次是直接调用API操作了，话不多说，进入主题
二、环境前提：
公司用的还是纯ElasticSearch的API库，并没有Spring-Data-ES的包装
ElasticSearch版本是7.3.1
这是封装的包：
<!-- es start --> <dependency> <groupId>cn.ymcd.comm</groupId> <artifactId>comm-elasticsearch</artifactId> <version>1.0.3</version> </dependency>
然后看下里面的ES依赖：
<dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-high-level-client</artifactId> <version>7.3.0</version><!--$NO-MVN-MAN-VER$--> </dependency> <dependency> <groupId>org.elasticsearch</groupId> <artifactId>elasticsearch</artifactId> <version>7.3.0</version><!--$NO-MVN-MAN-VER$--> </dependency> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>transport</artifactId> <version>7.3.0</version><!--$NO-MVN-MAN-VER$--> </dependency> <dependency> <groupId>org.elasticsearch.plugin</groupId> <artifactId>transport-netty4-client</artifactId> <version>7.3.0</version><!--$NO-MVN-MAN-VER$--> </dependency> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-client</artifactId> <version>7.3.0</version><!--$NO-MVN-MAN-VER$--> </dependency>
包源码只有一个客户端类：
类似JDBC的连接，提供主机，账户密码信息，调用客户端对象方法获取连接资源
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package cn.ymcd.comm.elasticsearch;
import cn.ymcd.comm.base.log.LogFactory;
import cn.ymcd.comm.base.log.YmcdLogger;
import java.util.Arrays;
import java.util.List;
import java.util.function.Function;
import java.util.stream.Collectors;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.RestClientBuilder.HttpClientConfigCallback;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
@Configuration
@Component("esClient")
public class EsRestClient implements AutoCloseable {
private YmcdLogger logger = LogFactory.getLogger(this.getClass());
@Value("${elasticsearch.host-name}")
private String hostName;
@Value("${elasticsearch.port:9200}")
private int port;
@Value("${elasticsearch.cluster:}")
private String cluster;
@Value("${elasticsearch.userName:}")
private String userName;
@Value("${elasticsearch.password:}")
private String password;
protected RestHighLevelClient client;
public EsRestClient() {
}
public RestHighLevelClient getEsClient() {
RestClientBuilder builder = null;
if (StringUtils.isNotBlank(this.cluster)) {
this.logger.debug("connect to cluster server...");
List<HttpHost> esHosts = (List)Arrays.stream(this.cluster.split(",")).map(HttpHost::create).collect(Collectors.toList());
builder = RestClient.builder((HttpHost[])esHosts.toArray(new HttpHost[esHosts.size()]));
} else {
this.logger.debug("connect to single node server...");
builder = RestClient.builder(new HttpHost[]{new HttpHost(this.hostName, this.port)});
}
if (StringUtils.isNotBlank(this.userName) && StringUtils.isNotBlank(this.password)) {
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(this.userName, this.password));
builder.setHttpClientConfigCallback(new HttpClientConfigCallback() {
public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
}
});
}
this.client = new RestHighLevelClient(builder);
this.logger.debug("connected to server!");
return this.client;
}
public void close() {
if (this.client != null) {
this.logger.debug("close es client...");
try {
this.client.close();
} catch (Exception var2) {
this.logger.error("close es client error!", var2);
}
}
}
}
三、API封装：
封装了，但是没完全封装
1、我要做一个翻页查询都没有，还得我自己加上去整一个，麻了
2、有提供一个ES的索引名称注解和泛型声明，为什么返回类型没有一个按泛型返回的，还得是自己写
package cn.ymcd.perception.common.service;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilder;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.sort.SortBuilder;
import java.util.List;
/**
* ES接口
*
* @projectName: perception-task-server
* @author: panx
* @date: 2023年09月12日 10:04
* @version: 1.0
*/
public interface IEsBaseService<T> {
/**
* 基础查询 根据id查询 数据
*
* @param entity
* @param id
* @return java.lang.String
* @author panx
* @createTime 2023/9/12 0012 17:14
*/
String getById(T entity, String id);
/**
* 根据多个id 查询数据信息
*
* @param entity
* @param list
* @return org.elasticsearch.action.search.SearchResponse
* @author panx
* @createTime 2023/9/12 0012 17:14
*/
SearchResponse findByIdsList(T entity, List<String> list);
/**
* 查询所有信息
*
* @param from
* @param size
* @param entity
* @return org.elasticsearch.search.SearchHit[]
* @author panx
* @createTime 2023/9/12 0012 17:15
*/
SearchHit[] queryAll(int from, int size, T entity);
/**
* 根据条件查询
*
* @param indexName
* @param page
* @param boolQueryBuilder
* @param highlightBuilder
* @param sortBuilder
* @return org.elasticsearch.action.search.SearchResponse
* @author panx
* @createTime 2023/9/12 0012 17:15
*/
SearchResponse whereQuery(String indexName, Page page, BoolQueryBuilder boolQueryBuilder, HighlightBuilder highlightBuilder, SortBuilder sortBuilder);
/**
* @author OnCloud9
* @date 2023/9/14 13:36
* @description 翻页查询
* @param tClass
* @param page
* @param boolQueryBuilder
* @param highlightBuilder
* @param sortBuilder
* @return com.baomidou.mybatisplus.extension.plugins.pagination.Page<T>
*/
<Entity> Page<Entity> pageQuery(Class<Entity> tClass, Page page, BoolQueryBuilder boolQueryBuilder, HighlightBuilder highlightBuilder, SortBuilder sortBuilder);
/**
* 设置高亮显示字段
*
* @param fields
* @return org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder
* @author panx
* @createTime 2023/9/12 0012 17:15
*/
HighlightBuilder highlightBuilder(String... fields);
/**
* 获取排序规则
*
* @param fieldSort
* @param isDesc
* @return org.elasticsearch.search.sort.SortBuilder
* @author panx
* @createTime 2023/9/12 0012 17:15
*/
SortBuilder getSortBuilder(String fieldSort, Boolean isDesc);
/**
* 获取高亮显示的值
*
* @param hit
* @param field
* @return java.lang.String
* @author panx
* @createTime 2023/9/12 0012 17:15
*/
String getHighlightContent(SearchHit hit, String field);
/**
* 查询 索引中所有满足条件数据 游标 查询
*
* @param response
* @param restHighLevelClient
* @return java.util.List<org.elasticsearch.search.SearchHits>
* @author panx
* @createTime 2023/9/12 0012 17:16
*/
List<SearchHits> getAllData(SearchResponse response, RestHighLevelClient restHighLevelClient);
/**
* 获取ES中的总数
*
* @param indexName
* @param boolQueryBuilder
* @return long
* @author panx
* @createTime 2023/9/12 0012 17:16
*/
long getCount(String indexName, BoolQueryBuilder boolQueryBuilder);
/**
* 获取 注解索引名称
*
* @param entity
* @return java.lang.String
* @author panx
* @createTime 2023/9/12 0012 17:16
*/
String getIndexName(T entity);
/**
* @author OnCloud9
* @date 2023/9/17 17:10
* @description 聚合查询
* @params [tClass, aggregationBuilder, resultName]
* @return java.util.List<java.util.Map<java.lang.String,java.lang.String>>
*/
<Entity> List<Terms.Bucket> getAggregationQuery(Class<Entity> tClass, AggregationBuilder aggregationBuilder, String resultName);
/**
* @author OnCloud9
* @date 2023/9/18 15:40
* @description 条件聚合查询
* @params [tClass, boolQueryBuilder, aggregationBuilder, resultName]
* @return java.util.List<org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket>
*/
<Entity> List<Terms.Bucket> getConditionAggregationQuery(
Class<Entity> tClass,
BoolQueryBuilder boolQueryBuilder,
AggregationBuilder aggregationBuilder,
String resultName
);
}
首先是实体的索引名称注解：
我们项目的mysql表名 直接对应到es的索引名上，数据来源也是mysql推到es上面，统一规范了
package cn.ymcd.perception.base;
import java.lang.annotation.*;
/***
* 注解 索引信息
* @param
* @return
* @author gaof
* @createTime 2020/3/17 17:05
* @version: 1.0
*/
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
public @interface EsIndex {
/***
* 索引名称
* @param
* @return java.lang.String
* @author gaof
* @createTime 2020/3/17 17:06
* @version: 1.0
*/
String indexName();
}
注解的获取方式，因为做ES的CRUD都需要知晓是在哪个索引下操作
所以每个方法必定需要索引的参数传入，
叼毛同事非要从对象反射过去找注解，我给他重载下，从字节对象读就行了
这里说下接口上的泛型声明很不好，因为我在写业务的时候发现并不是只有一个索引要操作，需要多个索引操作，这个泛型声明限定死了
所以我写的方法都改用方法泛型，这样调用的时候才支持不同的业务实体
@Override
public String getIndexName(T entity) {
EsIndex index = entity.getClass().getAnnotation(EsIndex.class);
String indexName = index.indexName();
if (StringUtils.isBlank(indexName)) {
logger.error("注解索引名称为空");
throw new ElasticsearchException("注解indexName(索引名称)为空");
}
return indexName;
}
public <Entity> String getIndexName(Class<Entity> tClass) {
EsIndex index = tClass.getAnnotation(EsIndex.class);
String indexName = index.indexName();
if (StringUtils.isBlank(indexName)) {
logger.error("注解索引名称为空");
throw new ElasticsearchException("注解indexName(索引名称)为空");
}
return indexName;
}
其它的就是如何操作API了
这里重点说下PageQuery这个方法，要解决几个问题：
1、怎么接收返回的结果，ES的结果叫命中对象，放在一个数组里面，存的是JSON串
这里根据入参的实体类字节对象，交给可以做JSON序列化的工具活化JSON给对象就行了，这里用的FastJson
2、解决翻页问题，这里我不想冗余代码了，所以直接在同事写的whereQuery基础上套参写
在查询前算好from + to的参数值，返回的结果集塞回Page翻页对象交出去，
可以不传Page对象，那我默认认为调用者需要查询全部记录，就按一般索引支持的最大记录数翻页
3、索引翻页问题，因为在2上面说过，索引存在一个最大记录数的限制，有可能这个索引存了一万五千条数据，但是翻页查询只能翻到前一万条数据
在这个封装的工具方法中可以使用getCount方法获取真实的总记录数，也可以通过查询响应的命中对象获取总共的命中数量
解决的方法可以参考下链接： https://zhuanlan.zhihu.com/p/489562200
无非就三种， 1 调参数加大、2 Scroll滚动查询、3 SearchAfter标记查询
而在我的业务场景就是把ES数据带到功能上，要翻页查询，经理说不能调参数，后面两种办法又不能实现分页功能
所以折中的办法就是不调整，查到1万位置，默认认为用户不需要再看后面的内容
@Override
public String getById(T entity, String id) {
String real = "";
String indexName = getIndexName(entity);
SearchSourceBuilder builder = new SearchSourceBuilder();
SearchRequest request = new SearchRequest(indexName);
builder.query(QueryBuilders.termQuery("id", id));
request.source(builder);
SearchResponse response = null;
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
for (SearchHit hit : response.getHits()) {
real = hit.getSourceAsString();
}
} catch (IOException e) {
logger.error("根据id查询数据获取索引异常", e);
}
return real;
}
@Override
public SearchResponse findByIdsList(T entity, List<String> list) {
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
SearchRequest request = new SearchRequest(getIndexName(entity));
sourceBuilder.query(QueryBuilders.termsQuery("id", list));
request.source(sourceBuilder);
SearchResponse response = null;
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
} catch (IOException e) {
logger.error("根据多个id查询数据异常", e);
}
return response;
}
@Override
public SearchHit[] queryAll(int from, int size, T entity) {
SearchRequest searchRequest = new SearchRequest(getIndexName(entity));
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query();
searchSourceBuilder.from(from);
searchSourceBuilder.size(size);
SearchHit[] hitsArr = null;
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
close();
SearchHits hits = searchResponse.getHits();
hitsArr = hits.getHits();
} catch (IOException e) {
this.logger.error("查询数据失败", e);
}
return hitsArr;
}
@Override
public SearchResponse whereQuery(String indexName, Page page, BoolQueryBuilder boolQueryBuilder, HighlightBuilder highlightBuilder, SortBuilder sortBuilder) {
if (StringUtils.isBlank(indexName)) {
return null;
}
SearchRequest searchRequest = new SearchRequest(indexName);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
// 设置查询条数
if (null != page) {
Long current = page.getCurrent();
Long size = page.getSize();
searchSourceBuilder.from(current.intValue());
searchSourceBuilder.size(size.intValue());
}
//设置需要排序的字段
if (null != sortBuilder) {
searchSourceBuilder.sort(sortBuilder);
}
// 设置高亮,使用默认的highlighter高亮器
if (null != highlightBuilder) {
searchSourceBuilder.highlighter(highlightBuilder);
}
searchSourceBuilder.query(boolQueryBuilder);
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
searchRequest.source(searchSourceBuilder);
logger.info("query ES where... indexName = " + indexName + ":" + searchSourceBuilder.toString());
return restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
} catch (Exception e) {
logger.error("查询ES数据信息失败", e);
}
return null;
}
@Override
public <Entity> Page<Entity> pageQuery(Class<Entity> tClass, Page page, BoolQueryBuilder boolQueryBuilder, HighlightBuilder highlightBuilder, SortBuilder sortBuilder) {
String indexName = getIndexName(tClass);
if (Objects.isNull(page)) page = new Page<>(1, 10000);
Long current = page.getCurrent();
page.setCurrent((current - 1L) * page.getSize());
SearchResponse searchResponse = whereQuery(indexName, page, boolQueryBuilder, highlightBuilder, sortBuilder);
SearchHits searchHits = searchResponse.getHits();
long value = searchResponse.getHits().getTotalHits().value; /* 超出最大记录数配置，按最大记录数返回 */
List<Entity> records = new ArrayList<>();
for (SearchHit searchHit : searchHits) {
String recordJson = searchHit.getSourceAsString();
logger.info("recordJson " + recordJson);
Entity t = JSON.parseObject(recordJson, tClass);
records.add(t);
}
page.setRecords(records);
page.setTotal(value);
return page;
}
@Override
public HighlightBuilder highlightBuilder(String... fields) {
if (null != fields && fields.length > 0) {
HighlightBuilder highlightBuilder = new HighlightBuilder();
for (String field : fields) {
highlightBuilder.field(field);
}
highlightBuilder.preTags("<span style=\"color:red;\">")
.postTags("</span>");
return highlightBuilder;
}
return null;
}
@Override
public SortBuilder getSortBuilder(String fieldSort, Boolean isDesc) {
if (Boolean.TRUE.equals(isDesc)) {
return SortBuilders.fieldSort(fieldSort).order(SortOrder.DESC);
}
return SortBuilders.fieldSort(fieldSort).order(SortOrder.ASC);
}
@Override
public String getHighlightContent(SearchHit hit, String field) {
if (StringUtils.isBlank(field)) {
return null;
}
HighlightField highlightField = hit.getHighlightFields().get(field);
StringBuilder sub = new StringBuilder();
if (null != highlightField) {
Text[] contents = highlightField.getFragments();
if (null != contents) {
for (Text t : contents) {
sub.append(t);
}
}
}
return sub.toString();
}
@Override
public List<SearchHits> getAllData(SearchResponse response, RestHighLevelClient restHighLevelClient) {
boolean succeeded = false;
List<SearchHits> hitList = new ArrayList<>();
try {
String scrollId = response.getScrollId();
SearchHits searchHits = response.getHits();
hitList.add(searchHits);
// 根据游标查询所有数据
while (searchHits.getHits() != null && searchHits.getHits().length > 0) {
SearchScrollRequest scrollRequest = new SearchScrollRequest(scrollId);
scrollRequest.scroll(TimeValue.timeValueMillis(30));
response = restHighLevelClient.scroll(scrollRequest, RequestOptions.DEFAULT);
scrollId = response.getScrollId();
searchHits = response.getHits();
hitList.add(searchHits);
}
// 查询完清除游标
ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
clearScrollRequest.addScrollId(scrollId);
ClearScrollResponse clearScrollResponse = restHighLevelClient.clearScroll(clearScrollRequest, RequestOptions.DEFAULT);
succeeded = clearScrollResponse.isSucceeded();
} catch (IOException e) {
logger.error("统一方法索引查询所有数据发生异常", e);
}
if (!succeeded) {
return new ArrayList<>();
}
return hitList;
}
@Override
public long getCount(String indexName, BoolQueryBuilder boolQueryBuilder) {
CountRequest countRequest = new CountRequest(indexName);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(boolQueryBuilder);
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
countRequest.source(searchSourceBuilder);
CountResponse countResponse = restHighLevelClient.count(countRequest, RequestOptions.DEFAULT);
return countResponse.getCount();
} catch (Exception e) {
logger.error("统计ES数据失败", e);
}
return 0L;
}
@SuppressWarnings("Duplicates")
@Override
public <Entity> List<Terms.Bucket> getAggregationQuery(Class<Entity> tClass, AggregationBuilder aggregationBuilder, String resultName) {
String indexName = getIndexName(tClass);
SearchRequest searchRequest = new SearchRequest(indexName);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.aggregation(aggregationBuilder);
searchSourceBuilder.size(0);
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
searchRequest.source(searchSourceBuilder);
logger.info("query ES where... indexName = " + indexName + ":" + searchSourceBuilder.toString());
SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
Aggregations aggregations = searchResponse.getAggregations();
Terms terms = aggregations.get(resultName);
List<? extends Terms.Bucket> buckets = terms.getBuckets();
List<Terms.Bucket> returnBuckets = new ArrayList<>(buckets.size());
returnBuckets.addAll(buckets);
return returnBuckets;
} catch (Exception e) {
logger.error("查询ES数据信息失败", e);
return Collections.emptyList();
}
}
@SuppressWarnings("Duplicates")
@Override
public <Entity> List<Terms.Bucket> getConditionAggregationQuery(Class<Entity> tClass, BoolQueryBuilder boolQueryBuilder, AggregationBuilder aggregationBuilder, String resultN
String indexName = getIndexName(tClass);
SearchRequest searchRequest = new SearchRequest(indexName);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.aggregation(aggregationBuilder);
searchSourceBuilder.query(boolQueryBuilder);
searchSourceBuilder.size(0);
try (RestHighLevelClient restHighLevelClient = getEsClient()) {
searchRequest.source(searchSourceBuilder);
logger.info("query ES where... indexName = " + indexName + ":" + searchSourceBuilder.toString());
SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
Aggregations aggregations = searchResponse.getAggregations();
Terms terms = aggregations.get(resultName);
List<? extends Terms.Bucket> buckets = terms.getBuckets();
List<Terms.Bucket> returnBuckets = new ArrayList<>(buckets.size());
returnBuckets.addAll(buckets);
return returnBuckets;
} catch (Exception e) {
logger.error("查询ES数据信息失败", e);
return Collections.emptyList();
}
}
标签：return,String,indexName,org,ElasticSearch,elasticsearch,应用,new,Java From： https://www.cnblogs.com/mindzone/p/17722894.html