Java操作ElasticSearch（完整）

旧城等待， 2022-11-07 11:42 4阅读 0赞

1、maven项目 ，添加pom依赖

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>org.example</groupId>
        <artifactId>esJava</artifactId>
        <version>1.0-SNAPSHOT</version>
        <dependencies>
            
            <dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>elasticsearch-rest-high-level-client</artifactId>
                <version>7.11.1</version>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.75</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.16.20</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.12.0</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
        </dependencies>
    
    </project>

## 2、连接es工具类，获取client ##

package com.hdit.es;
    
    import org.apache.http.HttpHost;
    import org.elasticsearch.client.RestClient;
    import org.elasticsearch.client.RestClientBuilder;
    import org.elasticsearch.client.RestHighLevelClient;
    import java.io.IOException;
    
    /** * @基本功能: 获取client对象 * @ClassName: EsDemo * @Description: TODO * @Author: lijiaming * @Date: 2021/3/11 9:02 * @Version 1.0 */
    public class EsDemo {  
    // 第一种连接es方式（简洁些）
        public static void main(String[] args) throws IOException { 
    // RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
    // new HttpHost("192.168.184.128",9200,"http"),
    // new HttpHost("192.168.184.128",9201,"http"),
    // new HttpHost("192.168.184.128",9202,"http")
    // ));
    // RestHighLevelClient client = EsDemo.getClient();
    // return client;
        }
        
        
    // 第二种连接es方式（分开写）
        public static RestHighLevelClient getClient(){ 
            HttpHost httpHost1 = new HttpHost("192.168.184.128",9200);
            HttpHost httpHost2 = new HttpHost("192.168.184.128",9201);
            HttpHost httpHost3 = new HttpHost("192.168.184.128",9202);
            RestClientBuilder clientBuilder = RestClient.builder(httpHost1,httpHost2,httpHost3);
            RestHighLevelClient client = new RestHighLevelClient(clientBuilder);
            return  client;
        }
    }

## 3、测试工具类，测试Java是否可以连接到es集群 ##

package com.hdit.es;
    
    import org.elasticsearch.client.RestHighLevelClient;
    import org.junit.Test;
    
    /** * @基本功能: 测试Java连接es * @ClassName: TestDemo * @Description: TODO * @Author: lijiaming * @Date: 2021/3/11 20:34 * @Version 1.0 */
    public class TestDemo { 
        @Test
        public void testConnect(){ 
            try { 
                RestHighLevelClient client = EsDemo.getClient();
                System.out.println("ok!");
            } catch (Exception e) { 
                System.out.println(e);
            }
        }
    }

## 4、创建索引、删除索引、查询索引 ##

package com.hdit.es;
    
    import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
    import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
    import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
    import org.elasticsearch.action.admin.indices.get.GetIndexRequest;
    import org.elasticsearch.action.support.master.AcknowledgedResponse;
    import org.elasticsearch.client.RequestOptions;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.xcontent.XContentBuilder;
    import org.elasticsearch.common.xcontent.json.JsonXContent;
    import org.junit.Test;
    import java.io.IOException;
    
    /** * @基本功能: java操作es----索引 * @ClassName: createIndex * @Description: TODO * @Author: lijiaming * @Date: 2021/3/11 20:36 * @Version 1.0 */
    public class TestIndex { 
        String index="person";
        String type="man";
        
        //4.1 创建索引
        @Test
        public void createIndex() throws IOException { 
            //1.索引的settings
            Settings.Builder settings = Settings.builder()
                    .put("number_of_shards", 3)
                    .put("number_of_replicas", 1);
            //2.索引的mappings
            XContentBuilder mappings = JsonXContent.contentBuilder();
            mappings.startObject()
                    .startObject("properties")
                    .startObject("name")
                    .field("type", "text")
                    .endObject()
                    .startObject("age")
                    .field("type", "integer")
                    .endObject()
                    .startObject("birthday")
                    .field("type", "date")
                    .field("format", "yyyy-MM-dd")
                    .endObject()
                    .endObject()
                    .endObject();
    
            //将settings和Mappings 封装到一个Request对象
            CreateIndexRequest request = new CreateIndexRequest(index).settings(settings).mapping(type, mappings);
            //通过Client对象连接ES并执行创建索引
            RestHighLevelClient client = EsDemo.getClient();
            CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);
            System.out.println("resp:" + createIndexResponse.toString());
    }
        //4.2 Java删除索引
        @Test
        public  void delete() throws IOException { 
            //1.准备request对象
            DeleteIndexRequest request=new DeleteIndexRequest();
            request.indices(index);
            //2.通过Cilent操作
            RestHighLevelClient client = EsDemo.getClient();
            AcknowledgedResponse delete=client.indices().delete(request,RequestOptions.DEFAULT);
            /* 3.输出 */
            System.out.println(delete);
        }
        
       //4.3 Java查询索引
        @Test
        public   void exists() throws IOException { 
            //1.准备request对象
            GetIndexRequest request=new GetIndexRequest();
            // 查询es中有没有person索引
            request.indices(index);
            //2.通过Cilent操作
            RestHighLevelClient client = EsDemo.getClient();
            boolean exists= client.indices().exists(request,RequestOptions.DEFAULT);
            //3.输出
            System.out.println(exists);
        }
    }

## 5、创建文档（类似数据库表中添加一行数据）、查询文档、修改文档、删除文档、批量添加文档、批量删除文档 ##

package com.hdit.es;
    
    import com.fasterxml.jackson.databind.ObjectMapper;
    import org.elasticsearch.action.bulk.BulkRequest;
    import org.elasticsearch.action.bulk.BulkResponse;
    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.update.UpdateRequest;
    import org.elasticsearch.action.update.UpdateResponse;
    import org.elasticsearch.client.RequestOptions;
    import org.elasticsearch.client.RestHighLevelClient;
    import org.elasticsearch.common.xcontent.XContentType;
    import org.junit.Test;
    import java.io.IOException;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    
    /** * @基本功能: es文档操作 * @ClassName: TestOperation * @Description: TODO * @Author: lijiaming * @Date: 2021/3/11 20:57 * @Version 1.0 */
    public class TestOperation { 
        String index = "person";
        String type = "man";
        RestHighLevelClient client = EsDemo.getClient();
        ObjectMapper mapper = new ObjectMapper();
        
        //5.1 创建文档
        @Test
        public void createDoc() throws IOException { 
            //1.准备一个json数据
            Person p =new Person(1,"张三",18,new Date());
            String json = mapper.writeValueAsString(p);
            //2.准备一个request对象（手动指定id)
            IndexRequest request = new IndexRequest(index,type,p.getId().toString());
            request.source(json, XContentType.JSON);
            //3.通过client对象执行添加
            IndexResponse resp = client.index(request, RequestOptions.DEFAULT);
            //4.输出返回结果
            System.out.println(resp.getResult().toString());
        }
    
        //5.2 获取文档内容
        @Test
        public void testGetDocument() throws IOException { 
            GetRequest request = new GetRequest(index, "1");
            GetResponse getResponse = client.get(request, RequestOptions.DEFAULT);
            // 打印文档内容
            System.out.println(getResponse.getSourceAsString());
            // 打印结果集合
            System.out.println(getResponse.getSource().entrySet());
            // 打印结果对象
            System.out.println(getResponse);
        }
    
        //5.3 根据id修改文档指定内容
        @Test
        public void update() throws IOException { 
            //创建Map修改指定内容
            Map<String,Object> doc= new HashMap<String, Object>();
            doc.put("name","张大三");
            String docID="1";
            // 修改id为1的文档信息
            UpdateRequest request=new UpdateRequest(index,type,docID);
            request.doc(doc);
            UpdateResponse update=client.update(request,RequestOptions.DEFAULT);
            System.out.println(update.getResult().toString());
        }
        
        //5.4 删除文档
        @Test
        public void delete() throws IOException { 
            DeleteRequest request=new DeleteRequest(index,type,"1");
            DeleteResponse resp=client.delete(request,RequestOptions.DEFAULT);
            System.out.println(resp.getResult().toString());
        }
        
        //5.5 批量添加文档
        @Test
        public void BulkDoc() throws IOException { 
            // 创建3个需要添加的对象
            Person p1= new Person(1,"张三",30,new Date());
            Person p2= new Person(2,"李四",40,new Date());
            Person p3= new Person(3,"马五",50,new Date());
    
            String json1= mapper.writeValueAsString(p1);
            String json2= mapper.writeValueAsString(p2);
            String json3= mapper.writeValueAsString(p3);
    
            // 创建Request,将准备好的数据封装进去
            BulkRequest request=new BulkRequest();
            request.add(new IndexRequest(index,type,p1.getId().toString()).source(json1,XContentType.JSON));
            request.add(new IndexRequest(index,type,p2.getId().toString()).source(json2,XContentType.JSON));
            request.add(new IndexRequest(index,type,p3.getId().toString()).source(json3,XContentType.JSON));
            BulkResponse resp=client.bulk(request,RequestOptions.DEFAULT);
            System.out.println(resp.toString());
        }
        
        //5.6 批量删除文档
        @Test
        public void bulkDeleteDoc() throws IOException { 
            BulkRequest  request=new BulkRequest();
            request.add(new DeleteRequest(index,type,"1"));
            request.add(new DeleteRequest(index,type,"2"));
            request.add(new DeleteRequest(index,type,"3"));
            BulkResponse resp=client.bulk(request,RequestOptions.DEFAULT);
            System.out.println(resp);
        }
    }