今天本来想使用Spring Boot来连接ES的，但是想了想，还是决定用ES官方的Java High Level REST Client，这样可以更好地帮助我理解Spring中ES的原理。
首先，我们在POM文件中引入(Jar包的版本要和ES的版本一致）
<properties>
<elasticsearch.version>7.6.0</elasticsearch.version>
</properties>
<dependencies>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
</dependencies>
然后我写了一个Utils类，大家可以看一下里面的注释，或者直接拿过去用我觉得更合适一些，也可以去我deGitHub上下载这个包模块 https://github.com/Raindtop/LDM/tree/master/ldm-common/src/main/java/com/raindrop/common/Utils
package com.raindrop.common.Utils;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.sun.org.apache.xpath.internal.operations.Bool;
import io.netty.util.internal.StringUtil;
import org.apache.http.HttpHost;
import org.apache.lucene.search.TotalHits;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.admin.indices.alias.Alias;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.ShardSearchFailure;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.client.indices.CreateIndexResponse;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.MatchQueryBuilder;
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.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.sort.FieldSortBuilder;
import org.elasticsearch.search.sort.ScoreSortBuilder;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.SuggestionBuilder;
import org.springframework.util.StringUtils;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.TimeUnit;
/*
* @Description TODO ElasticSearch工具类
* @Author zhang heson
* @Date 10:49 2020/3/29
**/
public class ElasticSearchUtils {
private static RestHighLevelClient client = null;
/*
* @Description TODO 获取ES的服务器
* @param: []
* @return: org.elasticsearch.client.RestHighLevelClient
* @auther: zhang hesong
* @date: 10:52 2020/3/29
*/
public RestHighLevelClient getClient() {
if (client == null) {
synchronized (ElasticSearchUtils.class) {
if (client == null) {
client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("localhost", 9200, "http") //ES服务器的配置信息
// , new HttpHost("localhost", 9200, "http") 多服务器配置
)
);
}
}
}
return client;
}
/*
* @Description TODO 创建索引
* @param: [indexName, alias, mappings, setting]
* @return: boolean
* @auther: zhang hesong
* @date: 11:43 2020/3/29
*/
public boolean createIndex(String indexName, String alias, JSONObject mappings, Settings setting){
boolean result = true;
try(RestHighLevelClient client = getClient();){
//创建索引名字
CreateIndexRequest request = new CreateIndexRequest(indexName);
//设置索引的settings
if (Optional.ofNullable(setting).isPresent()) {
request.settings(setting);
}
//设置索引的mapping
if (Optional.ofNullable(mappings).isPresent()) {
request.mapping(mappings.toJSONString(), XContentType.JSON);
}
//设置索引的别名
if (!StringUtil.isNullOrEmpty(alias)) {
request.alias(new Alias(alias));
}
//发送请求至ES----同步
CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
boolean acknowledged = response.isAcknowledged();
boolean shardAsknowledged = response.isShardsAcknowledged();
System.out.println("请求状态:" + (acknowledged && shardAsknowledged));
//发送请求至ES----异步（监听器形式）
// ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
// @Override
// public void onResponse(CreateIndexResponse createIndexResponse) {
//
// boolean acknowledged = createIndexResponse.isAcknowledged();
// boolean shardAsknowledged = createIndexResponse.isShardsAcknowledged();
// System.out.println("请求状态:" + (acknowledged && shardAsknowledged));
// }
//
// @Override
// public void onFailure(Exception e) {
// System.out.println("缩影创建异常");
// }
// };
// client.indices().createAsync(request, RequestOptions.DEFAULT, listener);
} catch (Exception e) {
e.printStackTrace();
result=false;
}
return result;
}
/*
* @Description TODO 创建索引测试
* @param: [args]
* @return: void
* @auther: zhang hesong
* @date: 11:47 2020/3/29
*/
// public static void main(String[] args) {
// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
// Settings settings = Settings.builder()
// .put("index.number_of_shards", 3)
// .put("index.number_of_replicas", 2).build();
// System.out.println(elasticSearchUtils.createIndex("test", null, null, settings));
// }
/*
* @Description TODO 向索引中添加数据或者修改数据
* @param: [index, id, data]
* @return: boolean
* @auther: zhang hesong
* @date: 15:43 2020/3/29
*/
public boolean addDocument(String index, String id, Map<String, Object> data){
boolean result = true;
try(RestHighLevelClient client = getClient();){
//设置插入的索引名和主键
IndexRequest request = new IndexRequest(index);
if (!StringUtil.isNullOrEmpty(id)){
request.id(id);
}
//设置类型，不推荐使用
// request.type("_doc");
request.source(data);
IndexResponse response = null;
try{
response = client.index(request, RequestOptions.DEFAULT);
}catch (ElasticsearchException e){
//判断是否存在版本冲突
if(e.status() == RestStatus.CONFLICT){
System.out.println("ES版本与Client-Jar版本不一致");
}
System.out.println("索引异常：" + e);
}
//处理返回的数据逻辑——同步
if(response != null){
String res_index = response.getIndex();
String res_type = response.getType();
String res_id = response.getId();
long version = response.getVersion();
System.out.println("index: " + res_index + ";\n" +
"type: " + res_type + ";\n" +
"id: " + res_id + ";\n" +
"version: " + version + ";\n");
if(response.getResult() == DocWriteResponse.Result.CREATED){
System.out.println("新增文档成功");
}else if (response.getResult() == DocWriteResponse.Result.UPDATED){
System.out.println("更新文档成功");
}
//分片处理信息
ReplicationResponse.ShardInfo shardInfo = response.getShardInfo();
if(shardInfo.getTotal() != shardInfo.getSuccessful()){
}
//如果有分片副本失败，可以获取失败原因信息
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);
}
}
}
//处理返回的数据逻辑——同步
// ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
// @Override
// public void onResponse(IndexResponse indexResponse) {
//
// }
//
// @Override
// public void onFailure(Exception e) {
//
// }
// };
// client.indexAsync(request, RequestOptions.DEFAULT, listener);
}catch (IOException e){
e.printStackTrace();
result = false;
}
return result;
}
/*
* @Description TODO 向索引中添加数据或者修改数据测试
* @param: [args]
* @return: void
* @auther: zhang hesong
* @date: 15:52 2020/3/29
*/
// public static void main(String[] args) {
// //add
// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
// Map<String, Object> data = new HashMap<>();
// data.put("name", "Jack");
// data.put("age", 18);
// data.put("birthday", "2020-03-29");
//
// elasticSearchUtils.addDocument("test", null, data);
// //update
//// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
//// Map<String, Object> data = new HashMap<>();
//// data.put("name", "Jack2");
//// data.put("age", 18);
//// data.put("birthday", "2020-03-29");
////
//// elasticSearchUtils.addDocument("test", "phdUJXEB7FKJ1xYIRsxH", data);
// }
/*
* @Description TODO 删除数据
* @param: [index, id]
* @return: boolean
* @auther: zhang hesong
* @date: 16:28 2020/3/29
*/
public boolean deleteDocument(String index, String id){
boolean result = true;
try(RestHighLevelClient client = getClient();){
DeleteRequest request = new DeleteRequest(index);
request.id(id);
DeleteResponse response = null;
try{
response = client.delete(request, RequestOptions.DEFAULT);
}catch (ElasticsearchException e){
//判断是否存在版本冲突
if(e.status() == RestStatus.CONFLICT){
System.out.println("ES版本与Client-Jar版本不一致");
}
System.out.println("索引异常：" + e);
}
if(Optional.ofNullable(response).isPresent()){
System.out.println("数据删除成功,ID:" + id);
}
//异步请求的写法和上面差不多，我就不重复写了
}catch (IOException e){
e.printStackTrace();
result = false;
}
return result;
}
/*
* @Description TODO 删除数据测试
* @param: [args]
* @return: void
* @auther: zhang hesong
* @date: 16:29 2020/3/29
*/
// public static void main(String[] args) {
// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
// elasticSearchUtils.deleteDocument("test", "phdUJXEB7FKJ1xYIRsxH");
// }
/*
* @Description TODO 获取单条数据
* @param: [index, id, includes, excludes]
* @return: java.util.Map<java.lang.String,java.lang.Object>
* @auther: zhang hesong
* @date: 16:45 2020/3/29
*/
public Map<String, Object> getDocument(String index, String id, String[] includes, String[] excludes){
Map<String, Object> result = null;
try(RestHighLevelClient client = getClient();) {
GetRequest request = new GetRequest(index);
request.id(id);
if(includes == null || includes.length == 0){
includes = Strings.EMPTY_ARRAY;
}
if(excludes == null || excludes.length == 0){
excludes = Strings.EMPTY_ARRAY;
}
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);
GetResponse response = client.get(request, RequestOptions.DEFAULT);
if(response != null){
String res_index = response.getIndex();
String res_id = response.getId();
if(response.isExists()){
long version = response.getVersion();
result = response.getSourceAsMap();
//获取字节串
// byte[] result = response.getSourceAsBytes();
//获取字节串
// String result = response.getSourceAsString();
}else{
System.out.println("无此数据");
}
}else{
System.out.println("无此数据");
}
//异步请求的写法和上面差不多，我就不重复写了
}catch (IOException e){
e.printStackTrace();
}
return result;
}
/*
* @Description TODO 获取单个数据的测试
* @param: [args]
* @return: void
* @auther: zhang hesong
* @date: 18:11 2020/3/29
*/
// public static void main(String[] args) {
// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
// Map<String, Object> map = elasticSearchUtils.getDocument("test", "pRdNJXEB7FKJ1xYI9MzX", null, new String[]{"name", "age"});
// System.out.println(JSON.toJSONString(map));
// }
/*
* @Description TODO 文档搜索功能关于QueryBuilder建议查看源码
* @param: [index, queryBuilder, includes, excludes, pageNum, pageSize]
* @return: java.util.List<java.util.Map<java.lang.String,java.lang.Object>>
* @auther: zhang hesong
* @date: 19:13 2020/3/29
*/
public List<Map<String, Object>> searchDocument(String index, QueryBuilder queryBuilder,
String[] includes, String[] excludes,
Integer pageNum, Integer pageSize){
List<Map<String, Object>> result = new ArrayList<>();
try(RestHighLevelClient client = getClient();){
SearchRequest searchRequest = new SearchRequest(index);
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
//设置查询体
searchSourceBuilder.query(queryBuilder == null ? QueryBuilders.matchAllQuery() : queryBuilder);
//设置页码
searchSourceBuilder.from(pageNum == null ? 0 : pageNum);
//设置每页显示数量
searchSourceBuilder.size(pageSize == null ? 10 : pageSize);
//设置查询超时时间
searchSourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
//根据评分进行排序
// searchSourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));
//根据主键进行排序
searchSourceBuilder.sort(new FieldSortBuilder("age").order(SortOrder.ASC));
if(includes == null || includes.length == 0){
includes = Strings.EMPTY_ARRAY;
}
if(excludes == null || excludes.length == 0){
excludes = Strings.EMPTY_ARRAY;
}
searchSourceBuilder.fetchSource(includes, excludes);
// 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);
// searchSourceBuilder.highlighter(highlightBuilder);
//加入聚合
// TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
// .field("company.keyword");
// aggregation.subAggregation(AggregationBuilders.avg("average_age")
// .field("age"));
// searchSourceBuilder.aggregation(aggregation);
//做查询建议
// SuggestionBuilder termSuggestionBuilder =
// SuggestBuilders.termSuggestion("user").text("kmichy");
// SuggestBuilder suggestBuilder = new SuggestBuilder();
// suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
// searchSourceBuilder.suggest(suggestBuilder);
searchRequest.source(searchSourceBuilder);
SearchResponse response = client.search(searchRequest,RequestOptions.DEFAULT);
//结果状态信息
RestStatus status = response.status();
TimeValue took = response.getTook();
Boolean terminatedEarly = response.isTerminatedEarly();
Boolean timeOut = response.isTimedOut();
//分片搜索情况
int totalShards = response.getTotalShards();
int successfulShards = response.getSuccessfulShards();
int failedShards = response.getFailedShards();
for (ShardSearchFailure failure : response.getShardFailures()) {
// 搜索失败处理
}
//处理搜索命中文档结果
SearchHits hits = response.getHits();
//搜索命中文档总数以及最高分
TotalHits totalHits = hits.getTotalHits();
float maxScore = hits.getMaxScore();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit: searchHits){
String hit_index = hit.getIndex();
String hit_id = hit.getId();
float hit_score = hit.getScore();
Map<String, Object> result_map = hit.getSourceAsMap();
//获取字节串
// byte[] result_byte = hit.getSourceAsBytes();
//获取字节串
// String result_string = hit.getSourceAsString();
result.add(result_map);
}
//异步请求的写法和上面差不多，我就不重复写了
}catch (IOException e){
e.printStackTrace();
}
return result;
}
/*
* @Description TODO 文档搜索功能测试
* @param: [args]
* @return: void
* @auther: zhang hesong
* @date: 19:14 2020/3/29
*/
// public static void main(String[] args) {
// ElasticSearchUtils elasticSearchUtils = new ElasticSearchUtils();
// QueryBuilder queryBuilder = new MatchQueryBuilder("name", "Jack");
// List<Map<String, Object>> list = elasticSearchUtils.searchDocument("test", queryBuilder, new String[]{"name"} , null, null, null);
//
// System.out.println(JSON.toJSONString(list));
// }
}
来源：oschina
链接：https://my.oschina.net/u/4109273/blog/3213830