table of Contents
ES is a service, using C/S structure
Client connection mode supported by ES
ES provides multiple programming language clients
ES provides two JAVA REST client versions
Java Low Level REST Client Description
Java High Level REST Client Description
Java High Level REST Client maven 集成
Java High Level REST Client initialization
QueryBuilder corresponding to various queries
AggregationBuilder corresponding to various aggregations
Java Client logger description
Init Client setting Available parameter description
Document API Document manipulation API
Code sample: es-java-client address
Spring Data Elasticsearch Learning Link
Introduction to ES Client
ES is a service, using C/S structure
Review the architecture of ES
Client connection mode supported by ES
- REST API, port 9200
- Transport connection port 9300
ES provides multiple programming language clients
Client api learning link https://www.elastic.co/guide/en/elasticsearch/client/index.html
Java REST Client
ES provides two JAVA REST client versions
- Java Low Level REST Client: A low-level REST client that interacts with the cluster via http. Users need to organize the request JSON string by themselves and parse the response JSON string. Compatible with all ES versions.
- Java High Level REST Client: A high-level REST client, based on the low-level REST client, adding related APIs such as marshalling requests and parsing responses.
Java Low Level REST Client Description
- For features, please refer to the introduction and use of maven:
https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html
- API doc please refer to:
https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-client/6.2.4/index.html.
Java High Level REST Client Description
- It has been added since 6.0.0, and the purpose is to process requests and responses in a java object-oriented way.
- Each API supports both synchronous and asynchronous methods, and the synchronous method directly returns a result object. The asynchronous method is suffixed with async, and the result is notified through the listener parameter.
- Advanced java REST client depends on Elasticsearch core project
Compatibility note
- Depends on java1.8 and Elasticsearch core project
- Please use the client version that is consistent with the server ES version
Java High Level REST Client maven 集成
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.2.4</version>
</dependency>
Java High Level REST Client initialization
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http")));
Given multiple node addresses in the cluster, load balance the client to send requests to this node address set
Client is no longer in use, remember to close it.
client.close();
API
For API and usage examples, please refer to:
- Create index
package com.dongnao.es_hrset_client;
import java.io.IOException;
import org.elasticsearch.action.admin.indices.alias.Alias;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentType;
public class CreateIndexDemo {
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建 创建索引request
CreateIndexRequest request = new CreateIndexRequest("mess");
// 2、设置索引的settings
request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
.put("index.number_of_replicas", 2) // 副本数
.put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
);
// 3、设置索引的mappings
request.mapping("_doc",
" {\n" +
" \"tweet\": {\n" +
" \"properties\": {\n" +
" \"message\": {\n" +
" \"type\": \"text\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }",
XContentType.JSON);
// 4、 设置索引的别名
request.alias(new Alias("mmm"));
// 5、 发送请求
// 5.1 同步方式发送请求
CreateIndexResponse createIndexResponse = client.indices()
.create(request);
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println("shardsAcknowledged = " + shardsAcknowledged);
// 5.1 异步方式发送请求
/*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
@Override
public void onResponse(
CreateIndexResponse createIndexResponse) {
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println(
"shardsAcknowledged = " + shardsAcknowledged);
}
@Override
public void onFailure(Exception e) {
System.out.println("创建索引异常：" + e.getMessage());
}
};
client.indices().createAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}
- index document
package com.dongnao.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.rest.RestStatus;
public class IndexDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建索引请求
IndexRequest request = new IndexRequest(
"mess", //索引
"_doc", // mapping type
"1"); //文档id
// 2、准备文档数据
// 方式一：直接给JSON串
String jsonString = "{" +
"\"user\":\"kimchy\"," +
"\"postDate\":\"2013-01-30\"," +
"\"message\":\"trying out Elasticsearch\"" +
"}";
request.source(jsonString, XContentType.JSON);
// 方式二：以map对象来表示文档
/*
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");
request.source(jsonMap);
*/
// 方式三：用XContentBuilder来构建文档
/*
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
builder.field("user", "kimchy");
builder.field("postDate", new Date());
builder.field("message", "trying out Elasticsearch");
}
builder.endObject();
request.source(builder);
*/
// 方式四：直接用key-value对给出
/*
request.source("user", "kimchy",
"postDate", new Date(),
"message", "trying out Elasticsearch");
*/
//3、其他的一些可选设置
/*
request.routing("routing"); //设置routing值
request.timeout(TimeValue.timeValueSeconds(1)); //设置主分片等待时长
request.setRefreshPolicy("wait_for"); //设置重刷新策略
request.version(2); //设置版本号
request.opType(DocWriteRequest.OpType.CREATE); //操作类别
*/
//4、发送请求
IndexResponse indexResponse = null;
try {
// 同步方式
indexResponse = client.index(request);
} catch(ElasticsearchException e) {
// 捕获，并处理异常
//判断是否版本冲突、create但文档已存在冲突
if (e.status() == RestStatus.CONFLICT) {
logger.error("冲突了，请在此写冲突处理逻辑！\n" + e.getDetailedMessage());
}
logger.error("索引异常", e);
}
//5、处理响应
if(indexResponse != null) {
String index = indexResponse.getIndex();
String type = indexResponse.getType();
String id = indexResponse.getId();
long version = indexResponse.getVersion();
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
System.out.println("新增文档成功，处理逻辑代码写到这里。");
} else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("修改文档成功，处理逻辑代码写到这里。");
}
// 分片处理信息
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
}
// 如果有分片副本失败，可以获得失败原因信息
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
String reason = failure.reason();
System.out.println("副本失败原因：" + reason);
}
}
}
//异步方式发送索引请求
/*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
@Override
public void onResponse(IndexResponse indexResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.indexAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}
- get document
package com.dongnao.es_hrset_client;
import java.io.IOException;
import java.util.Map;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
public class GetDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建索引请求
GetRequest request = new GetRequest(
"mess", //索引
"_doc", // mapping type
"1"); //文档id
// 2、可选的设置
//request.routing("routing");
//request.version(2);
//request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
//选择返回的字段
String[] includes = new String[]{"message", "*Date"};
String[] excludes = Strings.EMPTY_ARRAY;
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);
//也可写成这样
/*String[] includes = Strings.EMPTY_ARRAY;
String[] excludes = new String[]{"message"};
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);*/
// 取stored字段
/*request.storedFields("message");
GetResponse getResponse = client.get(request);
String message = getResponse.getField("message").getValue();*/
//3、发送请求
GetResponse getResponse = null;
try {
// 同步请求
getResponse = client.get(request);
} catch (ElasticsearchException e) {
if (e.status() == RestStatus.NOT_FOUND) {
logger.error("没有找到该id的文档" );
}
if (e.status() == RestStatus.CONFLICT) {
logger.error("获取时版本冲突了，请在此写冲突处理逻辑！" );
}
logger.error("获取文档异常", e);
}
//4、处理响应
if(getResponse != null) {
String index = getResponse.getIndex();
String type = getResponse.getType();
String id = getResponse.getId();
if (getResponse.isExists()) { // 文档存在
long version = getResponse.getVersion();
String sourceAsString = getResponse.getSourceAsString(); //结果取成 String
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap(); // 结果取成Map
byte[] sourceAsBytes = getResponse.getSourceAsBytes(); //结果取成字节数组
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
} else {
logger.error("没有找到该id的文档" );
}
}
//异步方式发送索引请求
/*
ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
@Override
public void onResponse(GetResponse getResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.getAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}
- Bulk
package com.dongnao.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.DocWriteRequest;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
public class BulkDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建批量操作请求
BulkRequest request = new BulkRequest();
request.add(new IndexRequest("mess", "_doc", "1")
.source(XContentType.JSON,"field", "foo"));
request.add(new IndexRequest("mess", "_doc", "2")
.source(XContentType.JSON,"field", "bar"));
request.add(new IndexRequest("mess", "_doc", "3")
.source(XContentType.JSON,"field", "baz"));
/*
request.add(new DeleteRequest("mess", "_doc", "3"));
request.add(new UpdateRequest("mess", "_doc", "2")
.doc(XContentType.JSON,"other", "test"));
request.add(new IndexRequest("mess", "_doc", "4")
.source(XContentType.JSON,"field", "baz"));
*/
// 2、可选的设置
/*
request.timeout("2m");
request.setRefreshPolicy("wait_for");
request.waitForActiveShards(2);
*/
//3、发送请求
// 同步请求
BulkResponse bulkResponse = client.bulk(request);
//4、处理响应
if(bulkResponse != null) {
for (BulkItemResponse bulkItemResponse : bulkResponse) {
DocWriteResponse itemResponse = bulkItemResponse.getResponse();
if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
|| bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) {
IndexResponse indexResponse = (IndexResponse) itemResponse;
//TODO 新增成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) {
UpdateResponse updateResponse = (UpdateResponse) itemResponse;
//TODO 修改成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) {
DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
//TODO 删除成功的处理
}
}
}
//异步方式发送批量操作请求
/*
ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
@Override
public void onResponse(BulkResponse bulkResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.bulkAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}
- search
package com.dongnao.es_hrset_client;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.ShardSearchFailure;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.term.TermSuggestion;
public class SearchDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
searchRequest.types("_doc");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
/*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
.fuzziness(Fuzziness.AUTO)
.prefixLength(3)
.maxExpansions(10);
sourceBuilder.query(matchQueryBuilder);*/
sourceBuilder.query(QueryBuilders.termQuery("age", 24));
sourceBuilder.from(0);
sourceBuilder.size(10);
sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
//是否返回_source字段
//sourceBuilder.fetchSource(false);
//设置返回哪些字段
/*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
String[] excludeFields = new String[] {"_type"};
sourceBuilder.fetchSource(includeFields, excludeFields);*/
//指定排序
//sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));
//sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
// 设置返回 profile
//sourceBuilder.profile(true);
//将请求体加入到请求中
searchRequest.source(sourceBuilder);
// 可选的设置
//searchRequest.routing("routing");
// 高亮设置
/*
HighlightBuilder highlightBuilder = new HighlightBuilder();
HighlightBuilder.Field highlightTitle =
new HighlightBuilder.Field("title");
highlightTitle.highlighterType("unified");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
highlightBuilder.field(highlightUser);
sourceBuilder.highlighter(highlightBuilder);*/
//加入聚合
/*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
.field("company.keyword");
aggregation.subAggregation(AggregationBuilders.avg("average_age")
.field("age"));
sourceBuilder.aggregation(aggregation);*/
//做查询建议
/*SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);*/
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
RestStatus status = searchResponse.status();
TimeValue took = searchResponse.getTook();
Boolean terminatedEarly = searchResponse.isTerminatedEarly();
boolean timedOut = searchResponse.isTimedOut();
//分片搜索情况
int totalShards = searchResponse.getTotalShards();
int successfulShards = searchResponse.getSuccessfulShards();
int failedShards = searchResponse.getFailedShards();
for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
// failures should be handled here
}
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
float maxScore = hits.getMaxScore();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
// do something with the SearchHit
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*
String documentTitle = (String) sourceAsMap.get("title");
List<Object> users = (List<Object>) sourceAsMap.get("user");
Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
*/
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
//取高亮结果
/*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
Text[] fragments = highlight.fragments();
String fragmentString = fragments[0].string();*/
}
// 获取聚合结果
/*
Aggregations aggregations = searchResponse.getAggregations();
Terms byCompanyAggregation = aggregations.get("by_company");
Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();
*/
// 获取建议结果
/*Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
}
}
*/
//异步方式发送获查询请求
/*
ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
@Override
public void onResponse(SearchResponse getResponse) {
//结果获取
}
@Override
public void onFailure(Exception e) {
//失败处理
}
};
client.searchAsync(searchRequest, listener);
*/
} catch (IOException e) {
logger.error(e);
}
}
}
- highlight
package com.dongnao.es_hrset_client;
import java.io.IOException;
import java.util.Map;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
public class HighlightDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
SearchRequest searchRequest = new SearchRequest("hl_test");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
sourceBuilder.query(matchQueryBuilder);
//分页设置
/*sourceBuilder.from(0);
sourceBuilder.size(5); ;*/
// 高亮设置
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.requireFieldMatch(false).field("title").field("content")
.preTags("<strong>").postTags("</strong>");
//不同字段可有不同设置，如不同标签
/*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title");
highlightTitle.preTags("<strong>").postTags("</strong>");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
highlightContent.preTags("<b>").postTags("</b>");
highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
sourceBuilder.highlighter(highlightBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
if(RestStatus.OK.equals(searchResponse.status())) {
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
//String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*String title = (String) sourceAsMap.get("title");
String content = (String) sourceAsMap.get("content"); */
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info("sourceMap : " + sourceAsMap);
//取高亮结果
Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("title highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("title", fragmentString);
}
}
highlight = highlightFields.get("content");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("content highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("content", fragmentString);
}
}
}
}
} catch (IOException e) {
logger.error(e);
}
}
}
- suggest
package com.dongnao.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.SuggestionBuilder;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.elasticsearch.search.suggest.term.TermSuggestion;
public class SuggestDemo {
private static Logger logger = LogManager.getRootLogger();
public static void termSuggest() {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("mess");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//词项建议
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
/*
"suggest": {
"my-suggestion": [
{
"text": "tring",
"offset": 0,
"length": 5,
"options": [
{
"text": "trying",
"score": 0.8,
"freq": 1
}
]
},
{
"text": "out",
"offset": 6,
"length": 3,
"options": []
},
{
"text": "elasticsearch",
"offset": 10,
"length": 13,
"options": []
}
]
}*/
} catch (IOException e) {
logger.error(e);
}
}
public static void completionSuggester() {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("music");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//自动补全
/*POST music/_search?pretty
{
"suggest": {
"song-suggest" : {
"prefix" : "lucene s",
"completion" : {
"field" : "suggest" ,
"skip_duplicates": true
}
}
}
}*/
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
.skipDuplicates(true);
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest");
for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (CompletionSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
} catch (IOException e) {
logger.error(e);
}
}
public static void main(String[] args) {
termSuggest();
logger.info("--------------------------------------");
completionSuggester();
}
}
- aggregation
package com.dongnao.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.builder.SearchSourceBuilder;
public class AggregationDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//加入聚合
//字段值项分组聚合
TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
.field("age").order(BucketOrder.aggregation("average_balance", true));
//计算每组的平均balance指标
aggregation.subAggregation(AggregationBuilders.avg("average_balance")
.field("balance"));
sourceBuilder.aggregation(aggregation);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取聚合结果
Aggregations aggregations = searchResponse.getAggregations();
Terms byAgeAggregation = aggregations.get("by_age");
logger.info("aggregation by_age 结果");
logger.info("docCountError: " + byAgeAggregation.getDocCountError());
logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
logger.info("------------------------------------");
for(Bucket buck : byAgeAggregation.getBuckets()) {
logger.info("key: " + buck.getKeyAsNumber());
logger.info("docCount: " + buck.getDocCount());
logger.info("docCountError: " + buck.getDocCountError());
//取子聚合
Avg averageBalance = buck.getAggregations().get("average_balance");
logger.info("average_balance: " + averageBalance.getValue());
logger.info("------------------------------------");
}
//直接用key 来去分组
/*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();*/
}
} catch (IOException e) {
logger.error(e);
}
}
}
QueryBuilder corresponding to various queries
AggregationBuilder corresponding to various aggregations
Java Client
Java Client description
- Java client uses TransportClient, and various operations are essentially asynchronous (you can use listener, or return Future).
- Note: In the development plan of ES, TransportClient will be abolished starting from version 7.0, and TransportClient will be completely removed in version 8.0 and replaced by High Level REST Client.
- The operation API in High Level REST Client and java client are mostly the same.
Official learning link
https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html
Compatibility note
- Please use the client version that is consistent with the server ES version
Java Client maven integration
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>6.2.4</version>
</dependency>
The other jars that depend on are basically the same as the high REST Client
Java Client logger description
The log4j2 log component is used. If you want to use other log components, you can use slf4j as a bridge
Init Client
// on startup
Settings settings = Settings.builder() //连接集群的设置
.put("cluster.name", "myClusterName").build();
TransportClient client = new PreBuiltTransportClient(settings)
.addTransportAddress(new TransportAddress(InetAddress.getByName("host1"), 9300))
.addTransportAddress(new TransportAddress(InetAddress.getByName("host2"), 9300));//连接的transport地址，注意端口是9300
// on shutdown
//在关闭时记得关闭客户端对象
client.close();
Init Client setting Available parameter description
- cluster.name specifies the name of the cluster. If the name of the cluster is not the default elasticsearch, you need to specify it.
- If client.transport.sniff is set to true, the entire cluster will be sniffed automatically, and the nodes of the cluster will be automatically added to the connection list.
- client.transport.ignore_cluster_name Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)
- client.transport.ping_timeout The time to wait for a ping response from a node. Defaults to 5s.
- client.transport.nodes_sampler_interval How often to sample / ping the nodes listed and connected. Defaults to 5s.
Document API Document manipulation API
Detailed introduction link on the official website: https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-docs.html
Search API
https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-search.html
Code sample: es-java-client address
http://code.dongnaoedu.com/3266399810/vip-elasticsearch/tree/master/
Spring Data Elasticsearch Learning Link
https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/ https://github.com/spring-projects/spring-data-elasticsearch.