一、说明：
一、Elasticsearch提供了两个JAVA REST Client版本：
1、java low level rest client:
低级别的rest客户端，通过http与集群交互，用户需自己编组请求JSON串，及解析响应JSON串。兼容所有Elasticsearch版本。
特点：maven引入
使用介绍: https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html
2、java high rest client:
高级别的REST客户端，基于低级别的REST客户端，增加了编组请求JSON串、解析响应JSON串等相关API，使用的版本需要保存和ES服务一致的版本，否则会有版本问题。
从6.0.0开始加入的，目的是以java面向对象的方式进行请求、响应处理。
每个API支持 同步、异步 两种方式，同步方法之间返回一个结果对象。异步的方法以async为后缀，通过listener参数来通知结果。高级java resy客户端依赖Elasticsearch core pproject
兼容性说明：
依赖jdk1.8和Elasticsearch core project
二、Java Low Level Rest Client的使用
版本：
Elasticsearch 6.3.1
pom文件：
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>6.3.1</version>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>6.3.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.7</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.7</version>
</dependency>
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>0.9</version>
</dependency>
一、构建elasicsearch client工具类
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;
import java.net.InetAddress;
/**
* @Author: xiaolaotou
* @Date: 2019/4/19
*/
/**
* 构建elasticsrarch client
*/
public class ClientUtil {
private static TransportClient client;
public TransportClient CreateClient() throws Exception {
// 先构建client
System.out.println("11111111111");
Settings settings=Settings.builder()
.put("cluster.name","elasticsearch1")
.put("client.transport.ignore_cluster_name", true) //如果集群名不对，也能连接
.build();
//创建Client
TransportClient client = new PreBuiltTransportClient(settings)
.addTransportAddress(
new TransportAddress(
InetAddress.getByName(
"192.168.200.100"),
9300));
return client;
}
}
二、测试类
import net.sf.json.JSONObject;
import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.get.GetResponse;
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.Requests;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHits;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
/**
* @Author: xiaolaotou
* @Date: 2019/4/19
* ElasticSearch 6.3.1
*/
public class Test {
private static TransportClient client;
static {
try {
client = new ClientUtil().CreateClient();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
//创建索引
// createEmployee();
//根据inde，type，id查询一个document的data
// FindIndex();
// CreateJsonIndex();
//批量导入
// BulkCreateIndex();
//批量导出
// OutData();
//创建带ik分词的index
// CreateIndexIkTest();
//更新索引
// UpdateIndex();
// createIndex2();
// Search();
get();
}
/**
* 创建索引，普通格式
*
* @throws Exception
*/
public static void createEmployee() throws Exception {
IndexResponse response = client.prepareIndex("student", "doc", "1")
.setSource(jsonBuilder()
.startObject()
.field("name", "jack")
.field("age", 27)
.field("position", "technique")
.field("country", "china")
.field("join_date", "2017-01-01")
.field("salary", 10000)
.endObject())
.get();
System.out.println("创建成功！");
}
/**
* 根据 index ，type，id查询
*
* @throws Exception
*/
public static void FindIndex() throws Exception {
GetResponse getResponse = client.prepareGet("student", "doc", "1").get();
System.out.println(getResponse.getSourceAsString());
}/**
* 创建索引，JSON
*
* @throws IOException
*/
public static void CreateJsonIndex() throws IOException {
JSONObject json = new JSONObject();
json.put("user", "小明");
json.put("title", "Java Engineer");
json.put("desc", "web 开发");
IndexResponse response = client.prepareIndex("studentjson", "doc", "1")
.setSource(json, XContentType.JSON)
.get();
String _index = response.getIndex();
System.out.println(_index);
}/**
* elasticsearch批量导入
*/
public static void BulkCreateIndex() {
BulkRequestBuilder builder = client.prepareBulk();
for (int i = 0; i < 100000; i++) {
HashMap<String, Object> map = new HashMap<>();
map.put("recordtime", "11");
map.put("area", "22");
map.put("usertype", "33");
map.put("count", 44);
builder.add(client.prepareIndex("bulktest", "1").setSource(map));
//每10000条提交一次
if (i % 10000 == 0) {
builder.execute().actionGet();
builder = client.prepareBulk();
}
}
}/**
* 批量导出
*/
public static void OutData() throws IOException {
SearchResponse response = client.prepareSearch("bulktest").setTypes("1")
.setQuery(QueryBuilders.matchAllQuery())
.setSize(10000).setScroll(new TimeValue(600000))
.setSearchType(SearchType.DEFAULT).execute().actionGet();
// setScroll(new TimeValue(600000)) 设置滚动的时间
String scrollid = response.getScrollId();
//把导出的结果以JSON的格式写到文件里
//每次返回数据10000条。一直循环查询知道所有的数据都被查询出来
while (true) {
SearchResponse response2 = client.prepareSearchScroll(scrollid).setScroll(new TimeValue(1000000))
.execute().actionGet();
SearchHits searchHit = response2.getHits();
//再次查询不到数据时跳出循环
if (searchHit.getHits().length == 0) {
break;
}
System.out.println("查询数量 ：" + searchHit.getHits().length);
for (int i = 0; i < searchHit.getHits().length; i++) {
String json = searchHit.getHits()[i].getSourceAsString();
putData(json);
}
System.out.println("查询结束");
}
}public static void putData(String json) throws IOException {
String str = json + "\n";
//写入本地文件
String fileTxt = "D:\\data.txt";
File file = new File(fileTxt);
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
if (!file.exists()) {
file.createNewFile();
FileWriter fw = new FileWriter(file, true);
BufferedWriter bw = new BufferedWriter(fw);
System.out.println("写入完成啦啊");
bw.write(String.valueOf(str));
bw.flush();
bw.close();
fw.close();
} else {
FileWriter fw = new FileWriter(file, true);
BufferedWriter bw = new BufferedWriter(fw);
System.out.println("追加写入完成啦啦");
bw.write(String.valueOf(str));
bw.flush();
bw.close();
fw.close();
}
}
/**
* 创建索引，并给某些字段指定ik分词器，以后向该索引中查询时，就会用ik分词
*/
public static void CreateIndexIkTest() throws Exception {
//创建映射
XContentBuilder mapping = XContentFactory.jsonBuilder()
.startObject()
.startObject("properties")
//title:字段名， type:文本类型 analyzer ：分词器类型
.startObject("title").field("type", "text").field("analyzer", "ik_smart").endObject() //该字段添加的内容，查询时将会使用ik_smart分词
.startObject("content").field("type", "text").field("analyzer", "ik_max_word").endObject()
.endObject()
.endObject();
//index：索引名 type：类型名（可以自己定义）
PutMappingRequest putmap = Requests.putMappingRequest("index").type("type").source(mapping);
//创建索引
client.admin().indices().prepareCreate("index").execute().actionGet();
//为索引添加映射
client.admin().indices().putMapping(putmap).actionGet();
//调用下面的方法为创建的索引添加内容
CreateIndex1();
}
//这个方法是为上一步创建的索引中添加内容，包括id，id不能重复
public static void CreateIndex1() throws IOException {
IndexResponse response = client.prepareIndex("index", "type", "1") //索引，类型，id
.setSource(jsonBuilder()
.startObject()
.field("title", "title") //字段，值
.field("content", "content")
.endObject()
).get();
}
/**
* 更新索引
*/
//更新索引，更新刚才创建的索引，如果id相同将会覆盖掉刚才的内容
public static void UpdateIndex() throws Exception {
//每次添加id应该不同，相当于数据表中的主键，相同的话将会进行覆盖
UpdateResponse response=client.update(new UpdateRequest("index","type","1")
.doc(XContentFactory.jsonBuilder()
.startObject()
.field("title","中华人民共和国国歌,国歌是最好听的歌")
.field("content","中华人民共和国国歌,国歌是最好听的歌")
.endObject()
)).get();
}
//再插入一条数据
public static void createIndex2() throws IOException {
IndexResponse response = client.prepareIndex("index", "type", "2")
.setSource(jsonBuilder()
.startObject()
.field("title", "中华民族是伟大的民族")
.field("content", "中华民族是伟大的民族")
.endObject()
).get();
}
/**
* 下面使用index索引下的2个document进行查询
*/
public static void Search(){
SearchResponse response1 = client.prepareSearch( "index") //指定多个索引
.setTypes("type") //指定类型
.setSearchType(SearchType.QUERY_THEN_FETCH)
.setQuery(QueryBuilders.matchQuery("title", "中华人民共和国国歌")) // Query
// .setPostFilter(QueryBuilders.rangeQuery("age").from(12).to(18)) // Filter
.setFrom(0).setSize(60).setExplain(true)
.get();
long totalHits1= response1.getHits().totalHits; //命中个数
System.out.println("response1======="+totalHits1);
SearchResponse response2 = client.prepareSearch( "index") //指定多个索引
.setTypes("type") //指定类型
.setSearchType(SearchType.QUERY_THEN_FETCH)
.setQuery(QueryBuilders.matchQuery("content", "中华人民共和国国歌")) // Query
// .setPostFilter(QueryBuilders.rangeQuery("age").from(12).to(18)) // Filter
.setFrom(0).setSize(60).setExplain(true)
.get();
long totalHits2 = response2.getHits().totalHits; //命中个数
System.out.println("response2========="+totalHits2);
}
/**
* GET操作
*/
public static void get() {
GetResponse response = client.prepareGet("index", "type", "2").get();
Map<String, Object> source = response.getSource();
Set<String> strings = source.keySet();
Iterator<String> iterator = strings.iterator();
while (iterator.hasNext()) {
System.out.println(source.get(iterator.next()));
}
}
}
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