Java操作ElasticSearch

1. 集群名称

默认集群名为elasticsearch，如果集群名称和指定的不一致则在使用节点资源时会报错。

2. 嗅探功能

通过client.transport.sniff启动嗅探功能，这样只需要指定集群中的某一个节点(不一定是主节点)，然后会加载集群中的其他节点，这样只要程序不停即使此节点宕机仍然可以连接到其他节点。

3. 查询类型SearchType

ES中一共有四种查询类型。

查询类型	描述	特点
QUERY_AND_FETCH	主节点将查询请求分发到所有的分片中，各个分片按照自己的查询规则即词频文档频率进行打分排序，然后将结果返回给主节点，主节点对所有数据进行汇总排序然后再返回给客户端，此种方式只需要和ES交互一次	①存在数据量和排序问题，主节点会汇总所有分片返回的数据，这样数据量会比较大②各个分片上的规则可能不一致
QUERY_THEN_FETCH	主节点将请求分发给所有分片，各个分片打分排序后将数据的id和分值返回给主节点，主节点收到后进行汇总排序，再根据排序后的id到对应的节点读取对应的数据再返回给客户端，此种方式需要和ES交互两次	解决了数据量问题但是排序问题依然存在，是ES的默认查询方式
DFS_QUERY_AND_FETCH	和前面两种的区别在于将各个分片的规则统一起来进行打分	解决了排序问题，但是仍然存在数据量问题
DFS_QUERY_THEN_FETCH	和前面两种的区别在于将各个分片的规则统一起来进行打分	解决了排序和数据量问题但是效率是最差的

特点：
一个交互两次，一个交互一次；一个统一打分规则一个不统一；一个分片返回详细数据一个分片返回id。

4. 分页压力

通过curl和Java查询时都可以指定分页，但是页数越往后服务器的压力会越大。大多数搜索引擎都不会提供非常大的页数搜索，原因有两个一是用户习惯一般不会看页数大的搜索结果，因为越往后越不准确，二是服务器压力。

比如分片是5，分页单位是10，查询第10000到10010条记录，ES需要在所有分片上进行查询，每个分片会产生10010条排序后的数据然后返回给主节点，主节点接收5个分片的数据一共是50050条，然后再进行汇总，最后再取其中的10000到10010条数据返回给客户端，这样一来看似只请求了10条数据，但实际上ES要汇总5万多条数据，所以页码越大服务器的压力就越大。

5. 超时timeout

查询时如果数据量很大，可以指定超时时间。即达到此时间后无论查询的结果是什么都会返回并且关闭连接，这样用户体验较好，缺点是查询出的数据可能不完整。
Java和curl都可以指定超时时间。

6. maven依赖

<dependency>  <groupId>org.elasticsearch</groupId>  <artifactId>elasticsearch</artifactId>  <version>1.4.4</version>  
</dependency>    
<dependency>  <groupId>com.fasterxml.jackson.core</groupId>  <artifactId>jackson-databind</artifactId>  <version>2.1.3</version>  
</dependency> 

7. Java代码

Java操作ES集群步骤
①配置集群对象信息
②创建客户端
③查看集群信息

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequestBuilder;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.deletebyquery.DeleteByQueryResponse;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchType;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.collect.ImmutableList;
import org.elasticsearch.common.settings.ImmutableSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.index.query.FilterBuilders;
import org.elasticsearch.index.query.MatchQueryBuilder.Operator;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.elasticsearch.search.aggregations.metrics.sum.Sum;
import org.elasticsearch.search.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.junit.Before;
import org.junit.Test;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;/** * @description Java操作ES    * @version 2016年11月25日*/
public class ElasticSearchTest {TransportClient transportClient;//索引库名称String index = "sl0";//类型名称String type = "student";@Beforepublic void before() {/*** 1.通过setting对象来指定集群配置信息*/Settings settings = ImmutableSettings.settingsBuilder().put("cluster.name", "elasticsearch")//指定集群名称.put("client.transport.sniff", true)//启动嗅探功能.build();/*** 2.创建客户端*     通过setting来创建，若不指定则默认链接的集群名为elasticsearch*     链接使用tcp协议即9300*/transportClient = new TransportClient(settings);TransportAddress transportAddress = new InetSocketTransportAddress("192.168.1.200", 9300);transportClient.addTransportAddress(transportAddress);/*** 3.查看集群信息*/ImmutableList<DiscoveryNode> connectedNodes = transportClient.connectedNodes();for (DiscoveryNode discoveryNode : connectedNodes) {System.out.println(discoveryNode.getHostAddress());}}/*** 通过prepareGet方法获取指定文档信息*/@Testpublic void testGet() {GetResponse getResponse = transportClient.prepareGet(index, type, "1").get();System.out.println(getResponse.getSourceAsString());}/*** 通过prepareUpdate更新索引库中文档，如果文档不存在则会报错* org.elasticsearch.index.engine.DocumentMissingException: [sl01][2] [student][6]: document missingat org.elasticsearch.action.update.UpdateHelper.prepare(UpdateHelper.java:82)at org.elasticsearch.action.update.TransportUpdateAction.shardOperation(TransportUpdateAction.java:176)at org.elasticsearch.action.update.TransportUpdateAction.shardOperation(TransportUpdateAction.java:170)at org.elasticsearch.action.support.single.instance.TransportInstanceSingleOperationAction$AsyncSingleAction$1.run(TransportInstanceSingleOperationAction.java:187)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)at java.lang.Thread.run(Thread.java:744)* @throws IOException */@Testpublic void testUpdate() throws IOException {XContentBuilder source = XContentFactory.jsonBuilder().startObject().field("name","will").endObject();UpdateResponse updateResponse = transportClient.prepareUpdate(index, type, "3").setDoc(source).get();System.out.println(updateResponse.getVersion());}/*** 通过prepareIndex增加文档，参数为json字符串* id相同做更新操作*/@Testpublic void testIndexJson() {String source = "{\"name\":\"qill\",\"age\":33}";IndexResponse indexResponse = transportClient.prepareIndex(index, type, "4").setSource(source).get();System.out.println(indexResponse.getVersion());}/*** 通过prepareIndex增加文档，参数为Map<String,Object>*/@Testpublic void testIndexMap() {Map<String, Object> source = new HashMap<String, Object>();source.put("name", "Alice");source.put("age", 18);IndexResponse indexResponse = transportClient.prepareIndex(index, type, "5").setSource(source).get();System.out.println(indexResponse.getVersion());}/*** 通过prepareIndex增加文档，参数为javaBean* 就是将JavaBean对象转成JSON字符串* @throws JsonProcessingException */@Testpublic void testIndexBean() throws JsonProcessingException {Student stu = new Student();stu.setName("Fresh");stu.setAge(22);ObjectMapper mapper = new ObjectMapper();String source = mapper.writeValueAsString(stu);IndexResponse indexResponse = transportClient.prepareIndex(index, type, "6").setSource(source).get();System.out.println(indexResponse.getVersion());}/*** 通过prepareIndex增加文档，参数为XContentBuilder* @throws IOException * @throws ExecutionException * @throws InterruptedException */@Testpublic void testIndexBuilder() throws IOException, InterruptedException, ExecutionException {XContentBuilder builder = XContentFactory.jsonBuilder().startObject().field("name","Avivi").field("age",30).endObject();IndexResponse indexResponse = transportClient.prepareIndex(index, type, "7").setSource(builder).execute().get();//.execute().get()和.get()效果一样  System.out.println(indexResponse.getVersion());}/*** 通过prepareIndex增加文档，参数直接以key-value格式设置，可以设置多个*/@Testpublic void testIndexDirect() {IndexResponse indexResponse = transportClient.prepareIndex(index, type, "8").setSource("name", "GAGA", "age", 35).get();System.out.println(indexResponse.getVersion());}/*** 通过prepareDelete删除文档*/@Testpublic void testDelete() {DeleteResponse deleteResponse = transportClient.prepareDelete(index, type, "9").get();System.out.println(deleteResponse.getVersion());//删除所有记录DeleteByQueryResponse deleteByQueryResponse = transportClient.prepareDeleteByQuery(index).setTypes(type).setQuery(QueryBuilders.matchAllQuery()).get();System.out.println(deleteByQueryResponse.contextSize());//0System.out.println(deleteByQueryResponse.isContextEmpty());//trueSystem.out.println(deleteByQueryResponse.status().getStatus());//200}/*** 删除索引库，不可逆，慎用* 浏览器访问出现{"error": "IndexMissingException[[sl01] missing]","status": 404}*/@Testpublic void testDeleteIndex() {DeleteIndexResponse deleteIndexResponse = transportClient.admin().indices().prepareDelete("sl01").get();System.out.println(deleteIndexResponse.isContextEmpty());}/*** 通过prepareCount求索引库文档总数*/@Testpublic void testCount() {long count = transportClient.prepareCount(index).get().getCount();System.out.println(count);}/*** 通过prepareBulk执行批处理* @throws IOException */@Testpublic void testBulk() throws IOException {//1.生成bulkBulkRequestBuilder bulk = transportClient.prepareBulk();//2.新增处理IndexRequest add = new IndexRequest(index, type, "10");add.source(XContentFactory.jsonBuilder().startObject().field("name", "Henrry").field("age", 28).endObject());//3.删除处理DeleteRequest delete = new DeleteRequest(index, type, "4");//4.修改处理XContentBuilder source = XContentFactory.jsonBuilder().startObject().field("name", "jack").field("age",17).endObject();UpdateRequest update = new UpdateRequest(index, type, "8");update.doc(source);bulk.add(delete);bulk.add(add);bulk.add(update);//5.执行批处理BulkResponse bulkResponse = bulk.get();if (bulkResponse.hasFailures()) {BulkItemResponse[] items = bulkResponse.getItems();for (BulkItemResponse item : items) {System.out.println(item.getFailureMessage());}} else {System.out.println("全部执行成功！");}}/*** 通过prepareSearch查询索引库* setQuery(QueryBuilders.matchQuery("name","jack"))* setSearchType(SearchType.QUERY_THEN_FETCH)*/@Testpublic void testSearch() {SearchResponse searchResponse = transportClient.prepareSearch(index).setTypes(type)//查询所有//.setQuery(QueryBuilders.matchAllQuery())//根据jack分词查询name，默认or.setQuery(QueryBuilders.matchQuery("name", "Avivi").operator(Operator.AND))//根据条件查询（注意关键词大小写AND，TO），支持name通配符，age大于等于0小于等于19               //.setQuery(QueryBuilders.queryString("name:A* AND age:[0 TO 19]"))//查询时不分词//.setQuery(QueryBuilders.termQuery("name", "Avivi")).setSearchType(SearchType.QUERY_THEN_FETCH)//查询类型.setFrom(0).setSize(10)//分页.addSort("age", SortOrder.DESC)//排序.get();SearchHits hits = searchResponse.getHits();long total = hits.getTotalHits();System.out.println(total);SearchHit[] searchHits = hits.hits();for (SearchHit searchHit : searchHits) {System.out.println(searchHit.getSourceAsString());}}/*** 多索引，多类型查询* Timeout //TODO timeout的作用是--{"name":"Avivi0","age":1}{"name":"Avivi5","age":6}{"name":"Avivi12","age":13}{"name":"Avivi17","age":18}{"name":"Avivi19","age":20}{"name":"Avivi24","age":25}{"name":"Avivi31","age":32}{"name":"Avivi36","age":37}{"name":"Avivi43","age":44}{"name":"Avivi48","age":49}* */@Testpublic void testSearchsAndTimeout() {SearchResponse searchResponse = transportClient.prepareSearch(index,"sl02").setTypes(type,"teacher").setQuery(QueryBuilders.matchAllQuery()).setSearchType(SearchType.QUERY_THEN_FETCH).setTimeout("3").get();SearchHits hits = searchResponse.getHits();long totalHits = hits.getTotalHits();System.out.println(totalHits);SearchHit[] hits2 = hits.getHits();for (SearchHit searchHit : hits2) {System.out.println(searchHit.getSourceAsString());}}/** * 过滤* lt 小于 * gt 大于 * lte 小于等于 * gte 大于等于 *  */ @Testpublic void testFilter() {SearchResponse searchResponse = transportClient.prepareSearch(index).setTypes(type).setQuery(QueryBuilders.matchAllQuery())//查询所有.setSearchType(SearchType.QUERY_THEN_FETCH)//.setPostFilter(FilterBuilders.rangeFilter("age")//      .from(0).to(19).includeLower(true).includeUpper(true)).setPostFilter(FilterBuilders.rangeFilter("age").gte(18).lte(22)).setExplain(true)//explain为true表示根据数据相关度排序，和关键字匹配最高的排在前面.get();SearchHits hits = searchResponse.getHits();long totalHits = hits.getTotalHits();System.out.println(totalHits);SearchHit[] hits2 = hits.getHits();for (SearchHit searchHit : hits2) {System.out.println(searchHit.getSourceAsString());}}/*** 高亮*/@Testpublic void testHighLight() {SearchResponse searchResponse = transportClient.prepareSearch(index).setTypes(type).setQuery(QueryBuilders.matchQuery("name", "Fresh")) //查询匹配的.setSearchType(SearchType.QUERY_THEN_FETCH).addHighlightedField("name").setHighlighterPreTags("<font color='red'>").setHighlighterPostTags("</font>").get();SearchHits hits = searchResponse.getHits();long totalHits = hits.getTotalHits();System.out.println(totalHits);SearchHit[] hits2 = hits.getHits();for (SearchHit searchHit : hits2) {Map<String, HighlightField> highlightFields = searchHit.getHighlightFields();HighlightField highlightField = highlightFields.get("name");if (null != highlightField) {Text[] fragments = highlightField.fragments();System.out.println(fragments[0]);}System.out.println(searchHit.getSourceAsString());}}/*** 分组*/@Testpublic void testGroupBy() {SearchResponse searchResponse = transportClient.prepareSearch(index).setTypes(type).setQuery(QueryBuilders.matchAllQuery()).setSearchType(SearchType.QUERY_THEN_FETCH)//根据age分组，默认返回10，size(0)也是10.addAggregation(AggregationBuilders.terms("group_age").field("age").size(0)).get();Terms terms = searchResponse.getAggregations().get("group_age");List<Bucket> buckets = terms.getBuckets();for (Bucket bucket : buckets) {System.out.println(bucket.getKey() + " " + bucket.getDocCount());}}/*** 聚合函数，本例只编写了sum，其他的聚合函数也可以实现*/@Testpublic void testAggregationFunction() {SearchResponse searchResponse = transportClient.prepareSearch(index).setTypes(type).setQuery(QueryBuilders.matchAllQuery()).setSearchType(SearchType.QUERY_THEN_FETCH).addAggregation(AggregationBuilders.terms("group_name").field("name")                                                              .subAggregation(AggregationBuilders.sum("sum_age").field("age"))).get();Terms terms = searchResponse.getAggregations().get("group_name");List<Bucket> buckets = terms.getBuckets();for (Bucket bucket : buckets) {Sum sum = bucket.getAggregations().get("sum_age");System.out.println(bucket.getKey()+" "+bucket.getDocCount()+" "+sum.getValue());}}/*** 生成sl02数据* @throws IOException * @throws ExecutionException * @throws InterruptedException */@Testpublic void generateOtherIndexData() throws IOException {for (int i = 25; i < 60; i++) {XContentBuilder builder = XContentFactory.jsonBuilder().startObject().field("name","Teacher"+i).field("age",i+1).endObject();transportClient.prepareIndex("sl02", "teacher", String.valueOf(i-24)).setSource(builder).get();}}/*** 生成数据* @throws IOException * @throws ExecutionException * @throws InterruptedException */@Testpublic void generateData() throws IOException {for (int i = 0; i < 60; i++) {XContentBuilder builder = XContentFactory.jsonBuilder().startObject().field("name","Avivi"+i).field("age",i+1).endObject();transportClient.prepareIndex(index, type, String.valueOf(i+11)).setSource(builder).get();}}/*** java操作settings和mappings* @throws IOException*/@Testpublic void testSettingsMappings() throws IOException {//1.settingsHashMap<String, Object> settings_map = new HashMap<String, Object>();settings_map.put("number_of_shards", 3);settings_map.put("number_of_replicas", 1);//2.mappingsXContentBuilder builder = XContentFactory.jsonBuilder().startObject().field("dynamic","student").startObject("properties").startObject("id").field("type","integer").field("store","yes").endObject().startObject("name").field("type","string").field("store","yes").field("index","analyzed").field("analyzer","id").endObject().endObject().endObject();CreateIndexRequestBuilder prepareCreate = transportClient.admin().indices().prepareCreate("sl04");prepareCreate.setSettings(settings_map).addMapping("student", builder).execute().actionGet();}/** * 指定分片 查询* * 分片查询Es会将数据均衡的存储在分片中，我们可以指定es去具体的分片或节点钟查询从而进一步的实现es极速查询。1：randomizeacross shards随机选择分片查询数据，es的默认方式2：_local优先在本地节点上的分片查询数据然后再去其他节点上的分片查询，本地节点没有IO问题但有可能造成负载不均问题。数据量是完整的。3：_primary只在主分片中查询不去副本查，一般数据完整。4：_primary_first优先在主分片中查，如果主分片挂了则去副本查，一般数据完整。5：_only_node只在指定id的节点中的分片中查询，数据可能不完整。6：_prefer_node优先在指定你给节点中查询，一般数据完整。7：_shards在指定分片中查询，数据可能不完整。8：_only_nodes可以自定义去指定的多个节点查询，es不提供此方式需要改源码。*  */  @Test  public void testPreference()  {  SearchResponse searchResponse = transportClient.prepareSearch(index)  .setTypes(type)  //.setPreference("_local")  //.setPreference("_primary")  //.setPreference("_primary_first")  //.setPreference("_only_node:ZYYWXGZCSkSL7QD0bDVxYA")  //.setPreference("_prefer_node:ZYYWXGZCSkSL7QD0bDVxYA")  .setPreference("_shards:0,1,2")  .setQuery(QueryBuilders.matchAllQuery()).setExplain(true).get();  SearchHits hits = searchResponse.getHits();  System.out.println(hits.getTotalHits());  SearchHit[] hits2 = hits.getHits();  for(SearchHit h : hits2) {  System.out.println(h.getSourceAsString());  }  }  /** * 调优* 合并索引片段  */  @Test  public void testOptimize() {  transportClient.admin().indices().prepareOptimize("sl01", "sl02")  .setMaxNumSegments(1).get();  } /** * 删除.del文件* 删除文档在es中删除一个文档后不会立即从硬盘中删除只会标记这个文档被删除，lucene会产生一个.del文件，而在检索过程中这个文件还会参与检索只不过在最后会被过滤掉，这样其实也会影响效率，我们可以定期删除这些文件*/  @Test  public void testOptimizeDel() {  transportClient.admin().indices().prepareOptimize("sl01", "sl02")  .setOnlyExpungeDeletes(true).get();  }  /** * 路由参数  * es极速查询Es将数据存储在不同的分片中，根据文档id通过内部算法得出要将文档存储在哪个分片上，所以在查询时只有指定在对应的分片上进行查询就可以实现基于es的极速查询，但是前提是你需要知道数据在那个分片上。还可以通过路由参数来设置数据存储在同一个分片中，setRouting(“”)* */  @Test  public void testRoutingInsert() {  String source = "{\"name\":\"中山大学l\",\"num\":1800}";  IndexResponse indexResponse = transportClient.prepareIndex(index, "stu")  .setRouting("student")  .setSource(source).get();  System.out.println(indexResponse.getVersion());  }  /** * 路由参数  */  @Test  public void testRoutingSearch() {  SearchResponse searchResponse = transportClient.prepareSearch(index)  .setTypes("stu")  .setQuery(QueryBuilders.matchAllQuery())  //.setPreference("_shards:0,1,2")  .setRouting("student", "teacher")  .get();  SearchHits hits = searchResponse.getHits();  SearchHit[] hits2 = hits.getHits();  for(SearchHit h : hits2) {  System.out.println(h.getSourceAsString());  }  }  public class Student {private String name;private int age;private String info;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getInfo() {return info;}public void setInfo(String info) {this.info = info;}}}

本文参考:
http://blog.csdn.net/ty4315/article/details/52434296