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步骤 描述 1. 创建索引在 Elasticsearch 创建索引并插入一些测试数据作为示例2. 创建查询使用 Java API 创建 Composite 查询3. 执行查询执行 Composite 查询并获得结果4. 分析处理结果 Composite 查询结果并处理
java es 中的 Composite 实例
2023-12-26 09:31:59
实现 Java ES 中的 Composite 实例简介
在 Java ES (Elasticsearch) 中,Composite 例子是一种将多个查询结果结合在一起的机制。它可以通过指定多个字段和排序规则对查询结果进行排序,并可以在页面上返回结果。本文将介绍如何使用它 Java 实现 Composite 实例。
流程下面是实现 Composite 例子的过程,并用表格展示每一步都需要做什么:
接下来,我们将逐步完成这些步骤,并提供相关的代码和注释。
1. 创建索引首先,我们需要在那里 Elasticsearch 创建索引并插入一些测试数据。以一个简单的学生信息为例,在这里创建一个名字 "students" 插入一些学生文档的索引。每个文档都包含 "name"、"age" 和 "grade" 字段。
import org.elasticsearch.action.bulk.BulkRequest;import org.elasticsearch.action.bulk.BulkResponse;import org.elasticsearch.action.index.IndexRequest;import org.elasticsearch.client.RequestOptions;import org.elasticsearch.client.RestHighLevelClient;import org.elasticsearch.common.xcontent.XContentType;import org.elasticsearch.index.Index;import org.elasticsearch.index.query.BoolQueryBuilder;import org.elasticsearch.index.query.QueryBuilders;import org.elasticsearch.index.query.TermQueryBuilder;import org.elasticsearch.index.query.TermsQueryBuilder;import org.elasticsearch.rest.RestStatus;import org.elasticsearch.search.builder.SearchSourceBuilder;import org.elasticsearch.search.sort.SortOrder;import java.io.IOException;import java.util.Arrays;import java.util.List;public class IndexCreationExample { private static final String INDEX_NAME = "students"; private static final String FIELD_NAME = "name"; private static final String FIELD_AGE = "age"; private static final String FIELD_GRADE = "grade"; public static void createIndexAndInsertData(RestHighLevelClient client) throws IOException { // 创建索引请求 CreateIndexRequest request = new CreateIndexRequest(INDEX_NAME); // 设置索引配置和映射 request.settings(Settings.builder() .put("index.number_of_shards", 1) .put("index.number_of_replicas", 1) ); request.mapping(getIndexMapping(), XContentType.JSON); // 发送创建索引请求 CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT); // 判断索引是否成功创建 if (createIndexResponse.isAcknowledged()) { // 插入测试数据 BulkResponse bulkResponse = insertTestData(client); if (bulkResponse.status() == RestStatus.CREATED) { System.out.println("成功创建索引并插入测试数据!"); } else { System.out.println("索引创建成功,但插入测试数据失败!"); } } else { System.out.println("索引创造失败!"); } } private static XContentBuilder getIndexMapping() throws IOException { XContentBuilder builder = XContentFactory.jsonBuilder(); builder.startObject(); builder.startObject("properties"); builder.startObject(FIELD_NAME) .field("type", "text") .endObject(); builder.startObject(FIELD_AGE) .field("type", "integer") .endObject(); builder.startObject(FIELD_GRADE) .field("type", "integer") .endObject(); builder.endObject(); builder.endObject(); return builder; } private static BulkResponse insertTestData(RestHighLevelClient client) throws IOException { BulkRequest bulkRequest = new BulkRequest(); List<Student> students = Arrays.asList( new Student("Alice", 20, 80), new Student("Bob", 19, 85), new Student("Charlie", 21, 90) ); for (Student student : students) { IndexRequest request = new IndexRequest(INDEX_NAME) .source(student.toMap(), XContentType.JSON); bulkRequest.add(request); } return client.bulk(bulkRequest, RequestOptions.DEFAULT); } private static class Student { private String name; private int age; private int grade; public Student(String name, int age, int grade) { this.name = name; this.age = age; this.grade = grade; } public Map<String, Object> toMap() { Map<String, Object> map = new HashMap<>(); map.put(FIELD_NAME, name); map.put(FIELD_AGE, age); map.put(FIELD_GRADE