526互联

Elasticsearch之JavaAPI操作ES

发布时间 2023-04-29 11:58:22作者: 上善若泪

目录

1 JavaAPI

1.1 pom.xml

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>7.9.0</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>7.9.0</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.9.0</version>
</dependency>

1.2 示例Demo

import org.apache.http.HttpHost;
import org.elasticsearch.ElasticsearchStatusException;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;

import java.io.IOException;

public class TestES4j {
    private static RestHighLevelClient client = new RestHighLevelClient(
            RestClient.builder(
                    new HttpHost("localhost", 9200, "http")
            ));

    public static void main(String[] args) throws IOException {
        String indexName = "test001";
        if(!checkExistIndex(indexName)){
            createIndex(indexName);
        }
        if(checkExistIndex(indexName)){
            deleteIndex(indexName);
        }
        checkExistIndex(indexName);
        client.close();
    }

    private static boolean checkExistIndex(String indexName) throws IOException {
        boolean result =true;
        try {
            OpenIndexRequest openIndexRequest = new OpenIndexRequest(indexName);
            client.indices().open(openIndexRequest,RequestOptions.DEFAULT).isAcknowledged();

        } catch (ElasticsearchStatusException ex) {
            String m = "type=index_not_found_exception, reason=no such index";
            if (ex.getMessage().contains(m)) {
                result = false;
            }
        }
        if(result)
            System.out.println("索引:" +indexName + " 是存在的");
        else
            System.out.println("索引:" +indexName + " 不存在");

        return result;

    }

    private static void deleteIndex(String indexName) throws IOException {
        DeleteIndexRequest request = new DeleteIndexRequest(indexName);
        client.indices().delete(request,RequestOptions.DEFAULT);
        System.out.println("删除了索引："+indexName);

    }

    private static void createIndex(String indexName) throws IOException {
        // TODO Auto-generated method stub
        CreateIndexRequest request = new CreateIndexRequest(indexName);
        client.indices().create(request,RequestOptions.DEFAULT);
        System.out.println("创建了索引："+indexName);
    }
}

1.3 操作文档

用的的实体：

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Product {
    private int id;
    private String name;
}

主要操作逻辑

import org.apache.http.HttpHost;
import org.elasticsearch.ElasticsearchStatusException;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class TestESCrud {

    private static RestHighLevelClient client
            = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
    private static String indexName = "test001";

    public static void main(String[] args) throws Exception{
		//校验索引和创建索引 同示例Demo，所以不在重复展出
        if(!checkExistIndex(indexName)){//确保索引存在
            createIndex(indexName);
        }

        Product product = new Product(); //准备数据
        product.setId(1);
        product.setName("product 1");

        addDocument(product);//增加文档

        getDocument(1); //获取文档

        product.setName("product 2"); //修改数据

        updateDocument(product);//修改文档

        getDocument(1); //获取文档

        deleteDocument(1); //删除文档

        getDocument(1); //获取文档

        client.close();
    }

    private static void deleteDocument(int id) throws IOException {
        DeleteRequest  deleteRequest = new DeleteRequest(indexName, String.valueOf(id));

        client.delete(deleteRequest,RequestOptions.DEFAULT);
        System.out.println("已经从ElasticSearch服务器上删除id="+id+"的文档");
    }

    private static void updateDocument(Product product) throws IOException {

        UpdateRequest updateRequest = new UpdateRequest (indexName, "product", String.valueOf(product.getId()))
                .doc("name",product.getName());

        client.update(updateRequest,RequestOptions.DEFAULT);
        System.out.println("已经在ElasticSearch服务器修改产品为："+product);

    }

    private static void getDocument(int id) throws IOException {
        // TODO Auto-generated method stub
        GetRequest request = new GetRequest(
                indexName,
                "product",
                String.valueOf(id));

        GetResponse response = client.get(request,RequestOptions.DEFAULT);

        if(!response.isExists()){
            System.out.println("检查到服务器上 "+"id="+id+ "的文档不存在");
        }
        else{
            String source = response.getSourceAsString();
            System.out.print("获取到服务器上 "+"id="+id+ "的文档内容是：");
            System.out.println(source);
        }
    }

    private static void addDocument(Product product) throws IOException {
        Map<String, Object> jsonMap = new HashMap<>();
        jsonMap.put("name", product.getName());
        IndexRequest indexRequest = new IndexRequest(indexName, "product", String.valueOf(product.getId()))
                .source(jsonMap);
        client.index(indexRequest,RequestOptions.DEFAULT);
        System.out.println("已经向ElasticSearch服务器增加产品："+product);
    }

}

注意：当在操作文档时，如果提示含有type的过时了，可把type参数去掉
点击了解Elasticsearch为什么要去除 表 type

1.4 批量操作文档

此时 需要另外引入的pom

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.8.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.83</version>
</dependency>

1.4.1 实体和工具类

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Product {
    private int id;
    private String name;
    private String category;
    private float price;
    private String place;
    private String code;
}

工具类

import org.apache.commons.io.FileUtils;
import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class ProductUtil {
    public static void main(String[] args) throws Exception{
        String fileName = "D:\\Users\\admin\\Desktop\\140k_products.txt";
        List<Product> productList = file2List(fileName);
        System.out.println(productList.size());
    }

    public static List<Product> file2List(String fileName) throws Exception{
        File file = new File(fileName);
        List<String> list = FileUtils.readLines(file, "utf-8");
        List<Product> productList = new ArrayList<>();
        for(String str:list){
            String[] split = str.split(",");
            Product product = new Product(Integer.parseInt(split[0]),split[1],split[2],Float.parseFloat(split[3]),split[4],split[5]);
            productList.add(product);
        }
        return productList;
    }
}

1.4.2 批量新增

import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpHost;
import org.elasticsearch.ElasticsearchStatusException;
import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;

import java.io.IOException;
import java.util.List;
import java.util.Map;

public class TestESBatch {

    private static RestHighLevelClient client
            = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
    private static String indexName = "test001";

    public static void main(String[] args) throws Exception{
         //检查索引和创建索引在示例Demo中已经存在，因此不在进行重复展示
        if(!checkExistIndex(indexName)){
            createIndex(indexName);
        }
        // 14万数据
        String fileName = "D:\\Users\\admin\\Desktop\\140k_products.txt";
        List<Product> productList = ProductUtil.file2List(fileName);
        System.out.printf("准备数据 %d 条",productList.size());
        batchInsert(productList);

        client.close();
    }

    private static void batchInsert(List<Product> productList) throws Exception{
        BulkRequest request = new BulkRequest();
        for(Product pro:productList){
            Map o = (Map) JSONObject.toJSON(pro);
            //此处的 .id方法 指定了就是自定义id 否则是用 ES生成id
            IndexRequest indexRequest= new IndexRequest(indexName).id(pro.getId()+"").source(o);
            request.add(indexRequest);
        }
        client.bulk(request,RequestOptions.DEFAULT);
        System.out.println("批量插入完成");
    }
}

1.5 查询操作

import org.apache.http.HttpHost;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.index.query.MatchQueryBuilder;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.sort.FieldSortBuilder;
import org.elasticsearch.search.sort.ScoreSortBuilder;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;

import java.io.IOException;

public class TestESQuery {

    private static RestHighLevelClient client
            = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200, "http")));
    private static String indexName = "test002";

    public static void main(String[] args) throws Exception {
        String keyword = "时尚连衣裙";
        int start = 0;
        int count = 10;

        SearchHits hits = search(keyword, start, count);

        SearchHit[] searchHits = hits.getHits();
        for (SearchHit hit : searchHits) {
            System.out.println(hit.getId()+"----"+hit.getScore()+"===="+hit.getSourceAsString());
        }
        client.close();
    }

    private static SearchHits search(String keyword, int start, int count) throws IOException {
        SearchRequest searchRequest = new SearchRequest(indexName);

        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //关键字匹配
        MatchQueryBuilder matchQueryBuilder = new MatchQueryBuilder("name",keyword );
        //模糊匹配
        matchQueryBuilder.fuzziness(Fuzziness.AUTO);
        sourceBuilder.query(matchQueryBuilder);
        sourceBuilder.from(start);//第几页
        sourceBuilder.size(count); //第几条
        //匹配 分值 度从高到低
        sourceBuilder.sort(SortBuilders.scoreSort().order(SortOrder.DESC));

//        sourceBuilder.sort(SortBuilders.fieldSort("price").order(SortOrder.ASC));
		//指定字段排序
        sourceBuilder.sort("price", SortOrder.DESC);

        searchRequest.source(sourceBuilder);
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = searchResponse.getHits();
        return hits;
    }
}