Elasticsearch之Java Api操作

红太狼 2024-03-23 12:12 48阅读 0赞

1、Elasticsearch概述  
2、Elasticsearch入门  
3、Elasticsearch之Java Api操作  
4、Elasticsearch集群搭建  
5、Elasticsearch进阶  
6、Elasticsearch集成SpringBoot  
7、Elasticsearch优化  
8、Elasticsearch系列总结

## 一、创建[Maven][]项目 ##

> [Elasticsearch][]软件是由 Java 语言开发的，所以也可以通过 Java API 的方式对 Elasticsearch服务进行访问。
> 
> 修改pom 文件，增加 Maven 依赖关系。

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pif5aSc5a2k5biG_size_14_color_FFFFFF_t_70_g_se_x_16][]

<dependencies>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.16.12</version>
            </dependency>
     
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
     
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
     
            <dependency>
                <groupId>org.elasticsearch</groupId>
                <artifactId>elasticsearch</artifactId>
                <version>7.8.0</version>
            </dependency>
            
            <dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>elasticsearch-rest-high-level-client</artifactId>
                <version>7.8.0</version>
            </dependency>
            
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-api</artifactId>
                <version>2.8.2</version>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-core</artifactId>
                <version>2.8.2</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.9.9</version>
            </dependency>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
        </dependencies>

### 1.1 客户端对象 ###

> 创建类，代码中创建 Elasticsearch 客户端对象
> 
> 因为早期版本的客户端对象已经不再推荐使用，且在未来版本中会被删除，所以这里我们采用高级 REST 客户端对象

public static void main(String[] args) throws IOException {
            // 创建客户端对象
            RestHighLevelClient client = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
     
            // 关闭客户端连接
            client.close();
        }

**注意：**

**9200** 端口为 Elasticsearch 的 Web 通信端口 **localhost** 为启动 ES 服务的主机名

执行代码，查看控制台信息：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5pif5aSc5a2k5biG_size_20_color_FFFFFF_t_70_g_se_x_16][]

## 二、索引操作 ##

> > ES服务器正常启动后，可以通过 Java API 客户端对象对 ES 索引进行操作

public class EsIndex {
     
        public static void main(String[] args) throws IOException {
     
            // 创建客户端对象
            RestHighLevelClient client = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
     
            // 关闭客户端连接
            client.close();
        }
     
        // 创建索引
        public static void createIndex(RestHighLevelClient client) throws IOException {
            // 创建索引 - 请求对象
            CreateIndexRequest request = new CreateIndexRequest("user");
            // 发送请求，获取响应
            CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
            boolean acknowledged = response.isAcknowledged();
            // 响应状态
            System.out.println("操作状态 = " + acknowledged);
        }
     
        // 查看索引
        public static void getIndex(RestHighLevelClient client) throws IOException {
            // 查询索引 - 请求对象
            GetIndexRequest request = new GetIndexRequest("user");
            // 发送请求，获取响应
            GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
            System.out.println("aliases: " + response.getAliases());
            System.out.println("mappings: " + response.getMappings());
            System.out.println("settings: " + response.getSettings());
        }
     
        // 删除索引
        public static void deleteIndex(RestHighLevelClient client) throws IOException {
            // 删除索引 - 请求对象
            DeleteIndexRequest request = new DeleteIndexRequest("user");
            // 发送请求，获取响应
            AcknowledgedResponse response = client.indices().delete(request, RequestOptions.DEFAULT);
            // 操作结果
            System.out.println("操作结果: " + response.isAcknowledged());
        }
    }

## 三、文档操作 ##

public class EsDoc {
     
        public static void main(String[] args) throws IOException {
            // 创建客户端对象
            RestHighLevelClient client = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
     
            // 关闭客户端连接
            client.close();
        }
     
        // 创建文档
        public static void createDoc(RestHighLevelClient client) throws IOException {
            // 新增文档 - 请求对象
            IndexRequest request = new IndexRequest();
            // 设置索引及唯一性标识
            request.index("user").id("1001");
            // 创建数据对象
            User user = new User();
            user.setAge(26);
            user.setSex("男");
            user.setName("jak");
            ObjectMapper objectMapper = new ObjectMapper();
            String productJson = objectMapper.writeValueAsString(user);
            // 添加文档数据, 数据格式为Json格式
            request.source(productJson, XContentType.JSON);
            // 客户端发送请求，获取响应对象
            IndexResponse response = client.index(request, RequestOptions.DEFAULT);
            // 打印结果信息
            System.out.println("_index: " + response.getIndex());
            System.out.println("id: " + response.getId());
            System.out.println("_result: " + response.getResult());
        }
     
        // 修改文档
        public static void updateDoc(RestHighLevelClient client) throws IOException {
            // 修改文档 - 请求对象
            UpdateRequest request = new UpdateRequest();
            // 配置修改参数
            request.index("user").id("1001");
            // 设置请求体，对数据进行修改
            request.doc(XContentType.JSON, "sex", "女");
            // 客户端发送请求，获取响应对象
            UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
            System.out.println("_index: " + response.getIndex());
            System.out.println("_id: " + response.getId());
            System.out.println("_result: " + response.getResult());
        }
     
        // 查询文档
        public static void getDoc(RestHighLevelClient client) throws IOException {
            // 创建请求对象
            GetRequest request = new GetRequest().index("user").id("1001");
            // 客户端发送请求，获取响应对象
            GetResponse response = client.get(request, RequestOptions.DEFAULT);
            // 打印结果信息
            System.out.println("_index: " + response.getIndex());
            System.out.println("_type: " + response.getType());
            System.out.println("_id: " + response.getId());
            System.out.println("source: " + response.getSourceAsString());
        }
     
        // 删除文档
        public static void deleteDoc(RestHighLevelClient client) throws IOException {
            // 创建请求对象
            DeleteRequest request = new DeleteRequest().index("user").id("1");
            // 客户端发送请求，获取响应对象
            DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
            // 打印信息
            System.out.println(response.toString());
        }
     
        // 批量新增
        public static void bulkCreateDoc(RestHighLevelClient client) throws IOException {
            // 创建批量新增请求对象
            BulkRequest request = new BulkRequest();
            request.add(new IndexRequest().index("user").id("1001").source(XContentType.JSON, "name", "zhangsan"));
            request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "lisi"));
            request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "wangwu"));
            // 客户端发送请求，获取响应对象
            BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
            // 打印结果信息
            System.out.println("took: " + responses.getTook());
            System.out.println("items: " + Arrays.toString(responses.getItems()));
        }
     
        // 批量删除
        public static void bulkDeleteDoc(RestHighLevelClient client) throws IOException {
            // 创建批量删除请求对象
            BulkRequest request = new BulkRequest();
            request.add(new DeleteRequest().index("user").id("1001"));
            request.add(new DeleteRequest().index("user").id("1002"));
            request.add(new DeleteRequest().index("user").id("1003"));
            // 客户端发送请求，获取响应对象
            BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
            // 打印结果信息
            System.out.println("took: " + responses.getTook());
            System.out.println("items: " + Arrays.toString(responses.getItems()));
     
        }
    }

## 四、高级查询 ##

public class EsSearch {
     
        public static void main(String[] args) throws IOException {
     
            // 创建客户端对象
            RestHighLevelClient client = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
     
            // 关闭客户端连接
            client.close();
        }
     
        // 查询所有索引数据
        public static void matchAllQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.matchAllQuery());
            request.source(sourceBuilder);
     
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
     
        }
     
        // term查询，查询条件为关键字
        public static void termQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.termQuery("age", "30"));
            request.source(sourceBuilder);
     
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 分页查询
        public static void pageQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.matchAllQuery());
     
            // 分页查询
            // 当前页起始索引(第一条数据的顺序号)，from
            sourceBuilder.from(0);
            // 每页显示多少条size
            sourceBuilder.size(2);
     
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 数据排序
        public static void sortOrderQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.matchAllQuery());
     
            // 排序
            sourceBuilder.sort("age", SortOrder.ASC);
     
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 过滤字段
        public static void filterFieldsQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.matchAllQuery());
     
            // 查询字段过滤
            String[] excludes = {};
            String[] includes = {"name", "age"};
            sourceBuilder.fetchSource(includes, excludes);
     
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // Bool查询
        public static void boolQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
     
            BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
            // 必须包含
            boolQueryBuilder.must(QueryBuilders.matchQuery("age", "30"));
            // 一定不含
            boolQueryBuilder.mustNot(QueryBuilders.matchQuery("name", "zhangsan"));
            // 可能包含
            boolQueryBuilder.should(QueryBuilders.matchQuery("sex", "男"));
     
            // 查询所有数据
            sourceBuilder.query(boolQueryBuilder);
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 范围查询
        public static void rangeQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
     
            RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("age");
            // 大于等于
            rangeQuery.gte("30");
            // 小于等于
            rangeQuery.lte("40");
     
     
            // 查询所有数据
            sourceBuilder.query(rangeQuery);
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 范围查询
        public static void fuzzyQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
     
            // 查询所有数据
            sourceBuilder.query(QueryBuilders.fuzzyQuery("name", "zhangsan").fuzziness(Fuzziness.ONE));
            request.source(sourceBuilder);
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 高亮查询
        public static void highLightQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
     
            // 构建查询方式: 高亮查询
            TermsQueryBuilder termsQueryBuilder = QueryBuilders.termsQuery("name", "zhangsan");
            // 设置查询方式
            sourceBuilder.query(termsQueryBuilder);
     
            // 构建高亮字段
            HighlightBuilder highlightBuilder = new HighlightBuilder();
            // 设置标签前缀
            highlightBuilder.preTags("<font color='red'>");
            // 设置标签后缀
            highlightBuilder.postTags("</font>");
            // 设置高亮字段
            highlightBuilder.field("name");
            // 设置高亮构建对象
            sourceBuilder.highlighter(highlightBuilder);
            // 设置请求体
            request.source(sourceBuilder);
     
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 聚合查询
        public static void AggrQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
            // 设置请求体
            request.source(sourceBuilder);
            // 客户端发送请求，获取响应对象
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
     
        // 分组统计
        public static void groupQuery(RestHighLevelClient client) throws IOException {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("student");
     
            // 构建查询的请求体
            SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
            sourceBuilder.aggregation(AggregationBuilders.terms("age_group_by").field("age"));
            // 设置请求体
            request.source(sourceBuilder);
            // 客户端发送请求，获取响应对象
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
     
            // 查询匹配
            SearchHits hits = response.getHits();
            System.out.println("took: " + response.getTook());
            System.out.println("timeout: " + response.isTimedOut());
            System.out.println("total: " + hits.getTotalHits());
            System.out.println("MaxScore: " + hits.getMaxScore());
            System.out.println("hits------------->");
            for (SearchHit hit : hits) {
                // 输出每条查询的结果信息
                System.out.println(hit.getSourceAsString());
            }
            System.out.println("<-----------------");
        }
    }

[Maven]: https://so.csdn.net/so/search?q=Maven&spm=1001.2101.3001.7020
[Elasticsearch]: https://so.csdn.net/so/search?q=Elasticsearch&spm=1001.2101.3001.7020
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