java 对ElasticSearch数据库操作封装工具类（对你是否适用嘞）

在 Java 中封装 ElasticSearch（ES）数据库操作（ES版本之间变动挺大的，别轻易换版本），可以使得与 ES 的交互更加简洁和易于维护。通过封装常见的操作，如插入文档、查询、更新和删除等，我们可以创建一个高效的工具类来简化开发流程。以下是一个简单的 ES 操作工具类的封装示例。

1. 添加 Elasticsearch 依赖

首先，确保在项目中添加了 Elasticsearch 的 Java 客户端依赖。以下是 Maven 依赖配置：

<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.10.0</version> <!-- 请根据版本需求修改 -->
</dependency>

2. Elasticsearch 操作封装工具类

import org.apache.http.HttpHost;
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.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.query.QuerySearchResult;
import org.elasticsearch.search.query.QuerySearchResponse;
import org.elasticsearch.search.query.SearchRequest;
import org.elasticsearch.search.query.SearchResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.search.SearchHit;import java.io.IOException;
import java.util.ArrayList;
import java.util.List;public class ElasticSearchUtil {private static final String ES_HOST = "localhost";  // ES 集群地址private static final int ES_PORT = 9200;           // 默认端口号private static RestHighLevelClient client;// 静态初始化：创建 Elasticsearch 客户端static {client = new RestHighLevelClient(RestClient.builder(new HttpHost(ES_HOST, ES_PORT, "http")));}// 获取 Elasticsearch 客户端public static RestHighLevelClient getClient() {return client;}// 关闭 Elasticsearch 客户端连接public static void close() throws IOException {if (client != null) {client.close();}}// 插入文档public static void indexDocument(String index, String id, String jsonData) {IndexRequest request = new IndexRequest(index).id(id).source(jsonData);try {client.index(request, RequestOptions.DEFAULT);System.out.println("Document indexed successfully.");} catch (IOException e) {System.err.println("Failed to index document: " + e.getMessage());}}// 更新文档public static void updateDocument(String index, String id, String jsonData) {UpdateRequest request = new UpdateRequest(index, id).doc(jsonData);try {client.update(request, RequestOptions.DEFAULT);System.out.println("Document updated successfully.");} catch (IOException e) {System.err.println("Failed to update document: " + e.getMessage());}}// 查询文档public static List<String> searchDocuments(String index, String field, String value) {SearchRequest searchRequest = new SearchRequest(index);SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();sourceBuilder.query(QueryBuilders.matchQuery(field, value));searchRequest.source(sourceBuilder);List<String> results = new ArrayList<>();try {SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);SearchHit[] hits = searchResponse.getHits().getHits();for (SearchHit hit : hits) {results.add(hit.getSourceAsString());}} catch (IOException e) {System.err.println("Failed to search documents: " + e.getMessage());}return results;}// 删除文档public static void deleteDocument(String index, String id) {try {client.delete(new DeleteRequest(index, id), RequestOptions.DEFAULT);System.out.println("Document deleted successfully.");} catch (IOException e) {System.err.println("Failed to delete document: " + e.getMessage());}}public static void main(String[] args) throws IOException {// 插入文档示例String jsonData = "{\"name\":\"John\",\"age\":30}";indexDocument("users", "1", jsonData);// 查询文档示例List<String> documents = searchDocuments("users", "name", "John");for (String doc : documents) {System.out.println(doc);}// 更新文档示例String updatedData = "{\"name\":\"John\",\"age\":31}";updateDocument("users", "1", updatedData);// 删除文档示例deleteDocument("users", "1");// 关闭 Elasticsearch 客户端close();}
}

3. 功能说明

1. 客户端初始化与关闭

RestHighLevelClient 用于与 Elasticsearch 进行交互。
client = new RestHighLevelClient(...)：初始化客户端连接。
client.close()：关闭客户端连接，释放资源。

2. 插入文档：

public static void indexDocument(String index, String id, String jsonData) {IndexRequest request = new IndexRequest(index).id(id).source(jsonData);try {client.index(request, RequestOptions.DEFAULT);System.out.println("Document indexed successfully.");} catch (IOException e) {System.err.println("Failed to index document: " + e.getMessage());}
}

IndexRequest 用于向指定索引中插入文档。
source(jsonData)：文档内容以 JSON 格式传入。

3. 更新文档：

public static void updateDocument(String index, String id, String jsonData) {UpdateRequest request = new UpdateRequest(index, id).doc(jsonData);try {client.update(request, RequestOptions.DEFAULT);System.out.println("Document updated successfully.");} catch (IOException e) {System.err.println("Failed to update document: " + e.getMessage());}
}

UpdateRequest 用于更新指定 ID 的文档。

4. 查询文档：

public static List<String> searchDocuments(String index, String field, String value) {SearchRequest searchRequest = new SearchRequest(index);SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();sourceBuilder.query(QueryBuilders.matchQuery(field, value));searchRequest.source(sourceBuilder);List<String> results = new ArrayList<>();try {SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);SearchHit[] hits = searchResponse.getHits().getHits();for (SearchHit hit : hits) {results.add(hit.getSourceAsString());}} catch (IOException e) {System.err.println("Failed to search documents: " + e.getMessage());}return results;
}

SearchRequest 和 SearchSourceBuilder 用于构建查询请求。
QueryBuilders.matchQuery() 用于构建匹配查询。

5. 删除文档：

public static void deleteDocument(String index, String id) {try {client.delete(new DeleteRequest(index, id), RequestOptions.DEFAULT);System.out.println("Document deleted successfully.");} catch (IOException e) {System.err.println("Failed to delete document: " + e.getMessage());}
}