大数据-178 Elasticsearch 7.3 Java 实战：索引与文档 CRUD 全流程示例

摘要

本文详细介绍了使用 Elasticsearch 7.3.0 和 RestHighLevelClient 进行索引与文档 CRUD 操作的完整流程。

一、版本矩阵

组件	版本	说明
Elasticsearch Server	7.3.0	代码示例基于此版本
Rest High Level Client	7.3.0	与服务端版本匹配
Java	17	maven.compiler.source/target=17

二、Maven 依赖配置

<dependencies>
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.3.0</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

三、创建 RestHighLevelClient

RestClientBuilder builder = RestClient.builder(
    new HttpHost("h121.wzk.icu", 9200, "http"),
    new HttpHost("h122.wzk.icu", 9200, "http"),
    new HttpHost("h123.wzk.icu", 9200, "http")
);
RestHighLevelClient client = new RestHighLevelClient(builder);

四、索引操作

4.1 创建索引（JSON 方式）

CreateIndexRequest indexRequest = new CreateIndexRequest("wzk-icu-es-test");
String mapping = "{\"settings\":{},\"mappings\":{\"properties\":{\"description\":{\"type\":\"text\",\"analyzer\":\"ik_max_word\"},\"name\":{\"type\":\"text\"}}}}";
indexRequest.source(mapping, XContentType.JSON);
CreateIndexResponse indexResponse = client.indices().create(indexRequest, RequestOptions.DEFAULT);

4.2 创建索引（对象方式）

CreateIndexRequest createIndexRequest = new CreateIndexRequest("wzk-icu-es-2");
createIndexRequest.settings(Settings.builder()
    .put("index.number_of_shards", 5)
    .put("index.number_of_replicas", 1)
    .build());
XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
xContentBuilder.startObject();
xContentBuilder.startObject("properties");
xContentBuilder.startObject("description").field("type", "text").field("analyzer", "ik_max_word").endObject();
xContentBuilder.endObject();
xContentBuilder.endObject();
createIndexRequest.mapping(xContentBuilder);

4.3 删除索引

DeleteIndexRequest deleteRequest = new DeleteIndexRequest("wzk-icu-es-test");
AcknowledgedResponse deleteResponse = client.indices().delete(deleteRequest, RequestOptions.DEFAULT);

五、文档操作

5.1 添加文档

IndexRequest indexRequest = new IndexRequest("wzk-icu-es-2").id("1");
String str = "{\"name\":\"spark添加文档\",\"description\":\"spark技术栈\",\"studymodel\":\"online\"}";
indexRequest.source(str, XContentType.JSON);
IndexResponse index = client.index(indexRequest, RequestOptions.DEFAULT);

5.2 查询文档

GetRequest getRequest = new GetRequest("wzk-icu-es-2");
getRequest.id("1");
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
Map<String, Object> sourceMap = getResponse.getSourceAsMap();

5.3 查询所有文档

SearchRequest searchRequest = new SearchRequest();
searchRequest.indices("wzk-icu-es-2");
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchAllQuery());
searchRequest.source(sourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
SearchHits hits = searchResponse.getHits();
for (SearchHit sh : hits.getHits()) {
    Map<String, Object> map = sh.getSourceAsMap();
}

六、错误速查表

症状	根因	修复
Connection refused	ES 节点地址配置错误	检查 HttpHost 地址和端口
索引已存在	重复创建同名索引	先执行 indices().exists 检查
Mapping 解析异常	JSON 结构语法错误	使用在线 JSON 校验工具
搜索结果为空	分词器配置不当	检查 analyzer 配置

七、总结

本文提供了 Elasticsearch 7.3 Java API 的完整 CRUD 教程，包括：

• Maven 依赖配置
• RestHighLevelClient 初始化
• 索引的创建与删除
• 文档的增删改查
• 常见错误排查指南

适合需要维护 ES7 系统的开发者参考学习。