第1章 Elasticsearch概述

01-开篇

教学视频

结构化数据

非结构化数据

半结构化数据

02-技术选型

Elasticsearch 是什么

The Elastic Stack, 包括 Elasticsearch、 Kibana、 Beats 和 Logstash（也称为 ELK Stack）。能够安全可靠地获取任何来源、任何格式的数据，然后实时地对数据进行搜索、分析和可视化。

Elaticsearch，简称为 ES， ES 是一个开源的高扩展的分布式全文搜索引擎， 是整个 ElasticStack 技术栈的核心。

它可以近乎实时的存储、检索数据；本身扩展性很好，可以扩展到上百台服务器，处理 PB 级别的数据。

elastic
英 [ɪˈlæstɪk] 美 [ɪˈlæstɪk]
n. 橡皮圈(或带);松紧带
adj. 橡皮圈(或带)的;有弹性的;有弹力的;灵活的;可改变的;可伸缩的

全文搜索引擎

Google，百度类的网站搜索，它们都是根据网页中的关键字生成索引，我们在搜索的时候输入关键字，它们会将该关键字即索引匹配到的所有网页返回；还有常见的项目中应用日志的搜索等等。对于这些非结构化的数据文本，关系型数据库搜索不是能很好的支持。

一般传统数据库，全文检索都实现的很鸡肋，因为一般也没人用数据库存文本字段。进行全文检索需要扫描整个表，如果数据量大的话即使对 SQL 的语法优化，也收效甚微。建立了索引，但是维护起来也很麻烦，对于 insert 和 update 操作都会重新构建索引。

基于以上原因可以分析得出，在一些生产环境中，使用常规的搜索方式，性能是非常差的：

• 搜索的数据对象是大量的非结构化的文本数据。
• 文件记录量达到数十万或数百万个甚至更多。
• 支持大量基于交互式文本的查询。
• 需求非常灵活的全文搜索查询。
• 对高度相关的搜索结果的有特殊需求，但是没有可用的关系数据库可以满足。
• 对不同记录类型、非文本数据操作或安全事务处理的需求相对较少的情况。为了解决结构化数据搜索和非结构化数据搜索性能问题，我们就需要专业，健壮，强大的全文搜索引擎 。

这里说到的全文搜索引擎指的是目前广泛应用的主流搜索引擎。它的工作原理是计算机索引程序通过扫描文章中的每一个词，对每一个词建立一个索引，指明该词在文章中出现的次数和位置，当用户查询时，检索程序就根据事先建立的索引进行查找，并将查找的结果反馈给用户的检索方式。这个过程类似于通过字典中的检索字表查字的过程。

Elasticsearch 应用案例

• GitHub: 2013 年初，抛弃了 Solr，采取 Elasticsearch 来做 PB 级的搜索。 “GitHub 使用Elasticsearch 搜索 20TB 的数据，包括 13 亿文件和 1300 亿行代码”。
• 维基百科：启动以 Elasticsearch 为基础的核心搜索架构
• 百度：目前广泛使用 Elasticsearch 作为文本数据分析，采集百度所有服务器上的各类指标数据及用户自定义数据，通过对各种数据进行多维分析展示，辅助定位分析实例异常或业务层面异常。目前覆盖百度内部 20 多个业务线（包括云分析、网盟、预测、文库、直达号、钱包、 风控等），单集群最大 100 台机器， 200 个 ES 节点，每天导入 30TB+数据。
• 新浪：使用 Elasticsearch 分析处理 32 亿条实时日志。
• 阿里：使用 Elasticsearch 构建日志采集和分析体系。
• Stack Overflow：解决 Bug 问题的网站，全英文，编程人员交流的网站。

03-教学大纲

• 第1章 Elasticsearch概述
• 第2章 Elasticsearch入门
• 第3章 Elasticsearch环境
• 第4章 Elasticsearch进阶
• 第5章 Elasticsearch集成
• 第6章 Elasticsearch优化
• 第7章 Elasticsearch面试题

第2章 Elasticsearch入门

04-入门-环境准备

官方网址

官方文档

Elasticsearch 7.8.0下载页面

Windows 版的 Elasticsearch 压缩包，解压即安装完毕，解压后的 Elasticsearch 的目录结构如下 ：

解压后，进入 bin 文件目录，点击 elasticsearch.bat 文件启动 ES 服务 。

注意： 9300 端口为 Elasticsearch 集群间组件的通信端口， 9200 端口为浏览器访问的 http协议 RESTful 端口。

打开浏览器，输入地址： http://localhost:9200，测试返回结果，返回结果如下：

{
  "name" : "DESKTOP-LNJQ0VF",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "nCZqBhfdT1-pw8Yas4QU9w",
  "version" : {
    "number" : "7.8.0",
    "build_flavor" : "default",
    "build_type" : "zip",
    "build_hash" : "757314695644ea9a1dc2fecd26d1a43856725e65",
    "build_date" : "2020-06-14T19:35:50.234439Z",
    "build_snapshot" : false,
    "lucene_version" : "8.5.1",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

05-入门-RESTful & JSON

REST 指的是一组架构约束条件和原则。满足这些约束条件和原则的应用程序或设计就是 RESTful。 Web 应用程序最重要的 REST 原则是，客户端和服务器之间的交互在请求之间是无状态的。从客户端到服务器的每个请求都必须包含理解请求所必需的信息。如果服务器在请求之间的任何时间点重启，客户端不会得到通知。此外，无状态请求可以由任何可用服务器回答，这十分适合云计算之类的环境。客户端可以缓存数据以改进性能。

在服务器端，应用程序状态和功能可以分为各种资源。资源是一个有趣的概念实体，它向客户端公开。资源的例子有：应用程序对象、数据库记录、算法等等。每个资源都使用 URI(Universal Resource Identifier) 得到一个唯一的地址。所有资源都共享统一的接口，以便在客户端和服务器之间传输状态。使用的是标准的 HTTP 方法，比如 GET、 PUT、 POST 和DELETE。

在 REST 样式的 Web 服务中，每个资源都有一个地址。资源本身都是方法调用的目
标，方法列表对所有资源都是一样的。这些方法都是标准方法，包括 HTTP GET、 POST、PUT、 DELETE，还可能包括 HEAD 和 OPTIONS。简单的理解就是，如果想要访问互联网上的资源，就必须向资源所在的服务器发出请求，请求体中必须包含资源的网络路径， 以及对资源进行的操作(增删改查)。

REST 样式的 Web 服务若有返回结果，大多数以JSON字符串形式返回。

06-入门-Postman客户端工具

如果直接通过浏览器向 Elasticsearch 服务器发请求，那么需要在发送的请求中包含
HTTP 标准的方法，而 HTTP 的大部分特性且仅支持 GET 和 POST 方法。所以为了能方便地进行客户端的访问，可以使用 Postman 软件Postman 是一款强大的网页调试工具，提供功能强大的 Web API 和 HTTP 请求调试。

软件功能强大，界面简洁明晰、操作方便快捷，设计得很人性化。 Postman 中文版能够发送任何类型的 HTTP 请求 (GET, HEAD, POST, PUT…)，不仅能够表单提交，且可以附带任意类型请求体。

Postman下载页面

07-入门-倒排索引

正排索引（传统）

倒排索引

Elasticsearch 是面向文档型数据库，一条数据在这里就是一个文档。 为了方便大家理解，我们将 Elasticsearch 里存储文档数据和关系型数据库 MySQL 存储数据的概念进行一个类比

ES 里的 Index 可以看做一个库，而 Types 相当于表， Documents 则相当于表的行。这里 Types 的概念已经被逐渐弱化， Elasticsearch 6.X 中，一个 index 下已经只能包含一个type， Elasticsearch 7.X 中, Type 的概念已经被删除了。

08-入门-HTTP-索引-创建

对比关系型数据库，创建索引就等同于创建数据库。

在 Postman 中，向 ES 服务器发 PUT 请求 ： http://127.0.0.1:9200/shopping

请求后，服务器返回响应：

{
    "acknowledged": true,//响应结果
    "shards_acknowledged": true,//分片结果
    "index": "shopping"//索引名称
}

后台日志：

[2021-04-08T13:57:06,954][INFO ][o.e.c.m.MetadataCreateIndexService] [DESKTOP-LNJQ0VF] [shopping] creating index, cause [api], templates [], shards [1]/[1], mappings []

如果重复发 PUT 请求 ： http://127.0.0.1:9200/shopping 添加索引，会返回错误信息 :

{
    "error": {
        "root_cause": [
            {
                "type": "resource_already_exists_exception",
                "reason": "index [shopping/J0WlEhh4R7aDrfIc3AkwWQ] already exists",
                "index_uuid": "J0WlEhh4R7aDrfIc3AkwWQ",
                "index": "shopping"
            }
        ],
        "type": "resource_already_exists_exception",
        "reason": "index [shopping/J0WlEhh4R7aDrfIc3AkwWQ] already exists",
        "index_uuid": "J0WlEhh4R7aDrfIc3AkwWQ",
        "index": "shopping"
    },
    "status": 400
}

09-入门-HTTP-索引-查询 & 删除

查看所有索引

在 Postman 中，向 ES 服务器发 GET 请求 ： http://127.0.0.1:9200/_cat/indices?v

这里请求路径中的_cat 表示查看的意思， indices 表示索引，所以整体含义就是查看当前 ES服务器中的所有索引，就好像 MySQL 中的 show tables 的感觉，服务器响应结果如下 :

health status index    uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   shopping J0WlEhh4R7aDrfIc3AkwWQ   1   1          0            0       208b           208b

查看单个索引

在 Postman 中，向 ES 服务器发 GET 请求 ： http://127.0.0.1:9200/shopping

返回结果如下：

{
    "shopping": {//索引名
        "aliases": {},//别名
        "mappings": {},//映射
        "settings": {//设置
            "index": {//设置 - 索引
                "creation_date": "1617861426847",//设置 - 索引 - 创建时间
                "number_of_shards": "1",//设置 - 索引 - 主分片数量
                "number_of_replicas": "1",//设置 - 索引 - 主分片数量
                "uuid": "J0WlEhh4R7aDrfIc3AkwWQ",//设置 - 索引 - 主分片数量
                "version": {//设置 - 索引 - 主分片数量
                    "created": "7080099"
                },
                "provided_name": "shopping"//设置 - 索引 - 主分片数量
            }
        }
    }
}

删除索引

在 Postman 中，向 ES 服务器发 DELETE 请求 ： http://127.0.0.1:9200/shopping

返回结果如下：

{
    "acknowledged": true
}

再次查看所有索引，GET http://127.0.0.1:9200/_cat/indices?v，返回结果如下：

health status index uuid pri rep docs.count docs.deleted store.size pri.store.size

成功删除。

10-入门-HTTP-文档-创建（Put & Post）

假设索引已经创建好了，接下来我们来创建文档，并添加数据。这里的文档可以类比为关系型数据库中的表数据，添加的数据格式为 JSON 格式

在 Postman 中，向 ES 服务器发 POST 请求 ： http://127.0.0.1:9200/shopping/_doc，请求体JSON内容为：

{
    "title":"小米手机",
    "category":"小米",
    "images":"http://www.gulixueyuan.com/xm.jpg",
    "price":3999.00
}

注意，此处发送请求的方式必须为 POST，不能是 PUT，否则会发生错误 。

返回结果：

{
    "_index": "shopping",//索引
    "_type": "_doc",//类型-文档
    "_id": "ANQqsHgBaKNfVnMbhZYU",//唯一标识，可以类比为 MySQL 中的主键，随机生成
    "_version": 1,//版本
    "result": "created",//结果，这里的 create 表示创建成功
    "_shards": {//
        "total": 2,//分片 - 总数
        "successful": 1,//分片 - 总数
        "failed": 0//分片 - 总数
    },
    "_seq_no": 0,
    "_primary_term": 1
}

上面的数据创建后，由于没有指定数据唯一性标识（ID），默认情况下， ES 服务器会随机生成一个。

如果想要自定义唯一性标识，需要在创建时指定： http://127.0.0.1:9200/shopping/_doc/1，请求体JSON内容为：

{
    "title":"小米手机",
    "category":"小米",
    "images":"http://www.gulixueyuan.com/xm.jpg",
    "price":3999.00
}

返回结果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",//<------------------自定义唯一性标识
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 1,
    "_primary_term": 1
}

此处需要注意：如果增加数据时明确数据主键，那么请求方式也可以为 PUT。

11-入门-HTTP-查询-主键查询 & 全查询

查看文档时，需要指明文档的唯一性标识，类似于 MySQL 中数据的主键查询

在 Postman 中，向 ES 服务器发 GET 请求 ： http://127.0.0.1:9200/shopping/_doc/1 。

返回结果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 1,
    "_seq_no": 1,
    "_primary_term": 1,
    "found": true,
    "_source": {
        "title": "小米手机",
        "category": "小米",
        "images": "http://www.gulixueyuan.com/xm.jpg",
        "price": 3999
    }
}

查找不存在的内容，向 ES 服务器发 GET 请求 ： http://127.0.0.1:9200/shopping/_doc/1001。

返回结果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1001",
    "found": false
}

查看索引下所有数据，向 ES 服务器发 GET 请求 ： http://127.0.0.1:9200/shopping/_search。

返回结果如下：

{
    "took": 133,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 2,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "1",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

12-入门-HTTP-全量修改 & 局部修改 & 删除

全量修改

和新增文档一样，输入相同的 URL 地址请求，如果请求体变化，会将原有的数据内容覆盖

在 Postman 中，向 ES 服务器发 POST 请求 ： http://127.0.0.1:9200/shopping/_doc/1

请求体JSON内容为:

{
    "title":"华为手机",
    "category":"华为",
    "images":"http://www.gulixueyuan.com/hw.jpg",
    "price":1999.00
}

修改成功后，服务器响应结果：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 2,
    "result": "updated",//<-----------updated 表示数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 2,
    "_primary_term": 1
}

局部修改

修改数据时，也可以只修改某一给条数据的局部信息

在 Postman 中，向 ES 服务器发 POST 请求 ： http://127.0.0.1:9200/shopping/_update/1。

请求体JSON内容为:

{
	"doc": {
		"title":"小米手机",
		"category":"小米"
	}
}

返回结果如下：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 3,
    "result": "updated",//<-----------updated 表示数据被更新
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 3,
    "_primary_term": 1
}

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_doc/1，查看修改内容：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 3,
    "_seq_no": 3,
    "_primary_term": 1,
    "found": true,
    "_source": {
        "title": "小米手机",
        "category": "小米",
        "images": "http://www.gulixueyuan.com/hw.jpg",
        "price": 1999
    }
}

删除

删除一个文档不会立即从磁盘上移除，它只是被标记成已删除（逻辑删除）。

在 Postman 中，向 ES 服务器发 DELETE 请求 ： http://127.0.0.1:9200/shopping/_doc/1

返回结果：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "_version": 4,
    "result": "deleted",//<---删除成功
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 4,
    "_primary_term": 1
}

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_doc/1，查看是否删除成功：

{
    "_index": "shopping",
    "_type": "_doc",
    "_id": "1",
    "found": false
}

13-入门-HTTP-条件查询 & 分页查询 & 查询排序

条件查询

假设有以下文档内容，（在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search）：

{
    "took": 5,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

URL带参查询

查找category为小米的文档，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search?q=category:小米，返回结果如下：

{
    "took": 94,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

上述为URL带参数形式查询，这很容易让不善者心怀恶意，或者参数值出现中文会出现乱码情况。为了避免这些情况，我们可用使用带JSON请求体请求进行查询。

请求体带参查询

接下带JSON请求体，还是查找category为小米的文档，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match":{
			"category":"小米"
		}
	}
}

返回结果如下：

{
    "took": 3,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

带请求体方式的查找所有内容

查找所有文档内容，也可以这样，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_all":{}
	}
}

则返回所有文档内容：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

查询指定字段

如果你想查询指定字段，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_all":{}
	},
	"_source":["title"]
}

返回结果如下：

{
    "took": 5,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机"
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机"
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1,
                "_source": {
                    "title": "小米手机"
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1,
                "_source": {
                    "title": "华为手机"
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1,
                "_source": {
                    "title": "华为手机"
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1,
                "_source": {
                    "title": "华为手机"
                }
            }
        ]
    }
}

分页查询

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_all":{}
	},
	"from":0,
	"size":2
}

返回结果如下：

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

查询排序

如果你想通过排序查出价格最高的手机，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_all":{}
	},
	"sort":{
		"price":{
			"order":"desc"
		}
	}
}

返回结果如下：

{
    "took": 96,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": null,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                },
                "sort": [
                    3999
                ]
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": null,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "sort": [
                    1999
                ]
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": null,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "sort": [
                    1999
                ]
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": null,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "sort": [
                    1999
                ]
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": null,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "sort": [
                    1999
                ]
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": null,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "sort": [
                    1999
                ]
            }
        ]
    }
}

14-入门-HTTP-多条件查询 & 范围查询

多条件查询

假设想找出小米牌子，价格为3999元的。（must相当于数据库的&&）

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"bool":{
			"must":[{
				"match":{
					"category":"小米"
				}
			},{
				"match":{
					"price":3999.00
				}
			}]
		}
	}
}

返回结果如下：

{
    "took": 134,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 2.3862944,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 2.3862944,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

假设想找出小米和华为的牌子。（should相当于数据库的||）

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"bool":{
			"should":[{
				"match":{
					"category":"小米"
				}
			},{
				"match":{
					"category":"华为"
				}
			}]
		},
        "filter":{
            "range":{
                "price":{
                    "gt":2000
                }
            }
        }
	}
}

返回结果如下：

{
    "took": 8,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1.3862942,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1.3862942,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1.3862942,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

范围查询

假设想找出小米和华为的牌子，价格大于2000元的手机。

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"bool":{
			"should":[{
				"match":{
					"category":"小米"
				}
			},{
				"match":{
					"category":"华为"
				}
			}],
            "filter":{
            	"range":{
                	"price":{
                    	"gt":2000
                	}
	            }
    	    }
		}
	}
}

返回结果如下：

{
    "took": 72,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 1.3862942,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1.3862942,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            }
        ]
    }
}

15-入门-HTTP-全文检索 & 完全匹配 & 高亮查询

全文检索

这功能像搜索引擎那样，如品牌输入“小华”，返回结果带回品牌有“小米”和华为的。

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match":{
			"category" : "小华"
		}
	}
}

返回结果如下：

{
    "took": 7,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 0.6931471,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 0.6931471,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 0.6931471,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

完全匹配

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_phrase":{
			"category" : "为"
		}
	}
}

返回结果如下：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    }
}

高亮查询

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"query":{
		"match_phrase":{
			"category" : "为"
		}
	},
    "highlight":{
        "fields":{
            "category":{}//<----高亮这字段
        }
    }
}

返回结果如下：

{
    "took": 100,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 3,
            "relation": "eq"
        },
        "max_score": 0.6931471,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": [
                        "华<em>为</em>"//<------高亮一个为字。
                    ]
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": [
                        "华<em>为</em>"
                    ]
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 0.6931471,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                },
                "highlight": {
                    "category": [
                        "华<em>为</em>"
                    ]
                }
            }
        ]
    }
}

16-入门-HTTP-聚合查询

聚合允许使用者对 es 文档进行统计分析，类似与关系型数据库中的 group by，当然还有很多其他的聚合，例如取最大值max、平均值avg等等。

接下来按price字段进行分组：

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"aggs":{//聚合操作
		"price_group":{//名称，随意起名
			"terms":{//分组
				"field":"price"//分组字段
			}
		}
	}
}

返回结果如下：

{
    "took": 63,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": 1,
        "hits": [
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "ANQqsHgBaKNfVnMbhZYU",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 3999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "A9R5sHgBaKNfVnMb25Ya",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BNR5sHgBaKNfVnMb7pal",
                "_score": 1,
                "_source": {
                    "title": "小米手机",
                    "category": "小米",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "BtR6sHgBaKNfVnMbX5Y5",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "B9R6sHgBaKNfVnMbZpZ6",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            },
            {
                "_index": "shopping",
                "_type": "_doc",
                "_id": "CdR7sHgBaKNfVnMbsJb9",
                "_score": 1,
                "_source": {
                    "title": "华为手机",
                    "category": "华为",
                    "images": "http://www.gulixueyuan.com/xm.jpg",
                    "price": 1999
                }
            }
        ]
    },
    "aggregations": {
        "price_group": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
                {
                    "key": 1999,
                    "doc_count": 5
                },
                {
                    "key": 3999,
                    "doc_count": 1
                }
            ]
        }
    }
}

上面返回结果会附带原始数据的。若不想要不附带原始数据的结果，在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"aggs":{
		"price_group":{
			"terms":{
				"field":"price"
			}
		}
	},
    "size":0
}

返回结果如下：

{
    "took": 60,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []
    },
    "aggregations": {
        "price_group": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
                {
                    "key": 1999,
                    "doc_count": 5
                },
                {
                    "key": 3999,
                    "doc_count": 1
                }
            ]
        }
    }
}

若想对所有手机价格求平均值。

在 Postman 中，向 ES 服务器发 GET请求 ： http://127.0.0.1:9200/shopping/_search，附带JSON体如下：

{
	"aggs":{
		"price_avg":{//名称，随意起名
			"avg":{//求平均
				"field":"price"
			}
		}
	},
    "size":0
}

返回结果如下：

{
    "took": 14,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 6,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []
    },
    "aggregations": {
        "price_avg": {
            "value": 2332.3333333333335
        }
    }
}

17-入门-HTTP-映射关系

有了索引库，等于有了数据库中的 database。

接下来就需要建索引库(index)中的映射了，类似于数据库(database)中的表结构(table)。

创建数据库表需要设置字段名称，类型，长度，约束等；索引库也一样，需要知道这个类型下有哪些字段，每个字段有哪些约束信息，这就叫做映射(mapping)。

先创建一个索引：

# PUT http://127.0.0.1:9200/user

返回结果：

{
    "acknowledged": true,
    "shards_acknowledged": true,
    "index": "user"
}

创建映射

# PUT http://127.0.0.1:9200/user/_mapping

{
    "properties": {
        "name":{
        	"type": "text",
        	"index": true
        },
        "sex":{
        	"type": "keyword",
        	"index": true
        },
        "tel":{
        	"type": "keyword",
        	"index": false
        }
    }
}

返回结果如下：

{
    "acknowledged": true
}

查询映射

#GET http://127.0.0.1:9200/user/_mapping

返回结果如下：

{
    "user": {
        "mappings": {
            "properties": {
                "name": {
                    "type": "text"
                },
                "sex": {
                    "type": "keyword"
                },
                "tel": {
                    "type": "keyword",
                    "index": false
                }
            }
        }
    }
}

增加数据

#PUT http://127.0.0.1:9200/user/_create/1001
{
	"name":"小米",
	"sex":"男的",
	"tel":"1111"
}

返回结果如下：

{
    "_index": "user",
    "_type": "_doc",
    "_id": "1001",
    "_version": 1,
    "result": "created",
    "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
    },
    "_seq_no": 0,
    "_primary_term": 1
}

查找name含有”小“数据：

#GET http://127.0.0.1:9200/user/_search
{
	"query":{
		"match":{
			"name":"小"
		}
	}
}

返回结果如下：

{
    "took": 495,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 0.2876821,
        "hits": [
            {
                "_index": "user",
                "_type": "_doc",
                "_id": "1001",
                "_score": 0.2876821,
                "_source": {
                    "name": "小米",
                    "sex": "男的",
                    "tel": "1111"
                }
            }
        ]
    }
}

查找sex含有”男“数据：

#GET http://127.0.0.1:9200/user/_search
{
	"query":{
		"match":{
			"sex":"男"
		}
	}
}

返回结果如下：

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 0,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []
    }
}

找不想要的结果，只因创建映射时"sex"的类型为"keyword"。

"sex"只能完全为”男的“，才能得出原数据。

#GET http://127.0.0.1:9200/user/_search
{
	"query":{
		"match":{
			"sex":"男的"
		}
	}
}

返回结果如下：

{
    "took": 2,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 0.2876821,
        "hits": [
            {
                "_index": "user",
                "_type": "_doc",
                "_id": "1001",
                "_score": 0.2876821,
                "_source": {
                    "name": "小米",
                    "sex": "男的",
                    "tel": "1111"
                }
            }
        ]
    }
}

查询电话

# GET http://127.0.0.1:9200/user/_search
{
	"query":{
		"match":{
			"tel":"11"
		}
	}
}

返回结果如下：

{
    "error": {
        "root_cause": [
            {
                "type": "query_shard_exception",
                "reason": "failed to create query: Cannot search on field [tel] since it is not indexed.",
                "index_uuid": "ivLnMfQKROS7Skb2MTFOew",
                "index": "user"
            }
        ],
        "type": "search_phase_execution_exception",
        "reason": "all shards failed",
        "phase": "query",
        "grouped": true,
        "failed_shards": [
            {
                "shard": 0,
                "index": "user",
                "node": "4P7dIRfXSbezE5JTiuylew",
                "reason": {
                    "type": "query_shard_exception",
                    "reason": "failed to create query: Cannot search on field [tel] since it is not indexed.",
                    "index_uuid": "ivLnMfQKROS7Skb2MTFOew",
                    "index": "user",
                    "caused_by": {
                        "type": "illegal_argument_exception",
                        "reason": "Cannot search on field [tel] since it is not indexed."
                    }
                }
            }
        ]
    },
    "status": 400
}

报错只因创建映射时"tel"的"index"为false。

18-入门-JavaAPI-环境准备

新建Maven工程。

添加依赖：

<dependencies>
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 的客户端 -->
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 依赖 2.x 的 log4j -->
    <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>
    <!-- junit 单元测试 -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

HelloElasticsearch

import java.io.IOException;

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

public class HelloElasticsearch {

	public static void main(String[] args) throws IOException {
		// 创建客户端对象
		RestHighLevelClient client = new RestHighLevelClient(
				RestClient.builder(new HttpHost("localhost", 9200, "http")));
//		...
		System.out.println(client);

		// 关闭客户端连接
		client.close();
	}
}

19-入门-JavaAPI-索引-创建

import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

import java.io.IOException;

public class CreateIndex {

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

        // 创建索引 - 请求对象
        CreateIndexRequest request = new CreateIndexRequest("user2");
        // 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);

        // 关闭客户端连接
        client.close();
    }

}

后台打印：

四月 09, 2021 2:12:08 下午 org.elasticsearch.client.RestClient logResponse
警告: request [PUT http://localhost:9200/user2?master_timeout=30s&include_type_name=true&timeout=30s] returned 1 warnings: [299 Elasticsearch-7.8.0-757314695644ea9a1dc2fecd26d1a43856725e65 "[types removal] Using include_type_name in create index requests is deprecated. The parameter will be removed in the next major version."]
操作状态 = true

Process finished with exit code 0

20-入门-JavaAPI-索引-查询 & 删除

查询

import org.apache.http.HttpHost;

import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.client.indices.GetIndexResponse;

import java.io.IOException;

public class SearchIndex {
    public static void main(String[] args) throws IOException {
        // 创建客户端对象
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));

        // 查询索引 - 请求对象
        GetIndexRequest request = new GetIndexRequest("user2");
        // 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());

        client.close();
    }
}

后台打印：

aliases:{user2=[]}
mappings:{user2=org.elasticsearch.cluster.metadata.MappingMetadata@ad700514}
settings:{user2={"index.creation_date":"1617948726976","index.number_of_replicas":"1","index.number_of_shards":"1","index.provided_name":"user2","index.uuid":"UGZ1ntcySnK6hWyP2qoVpQ","index.version.created":"7080099"}}

Process finished with exit code 0

删除

import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

import java.io.IOException;

public class DeleteIndex {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));
        // 删除索引 - 请求对象
        DeleteIndexRequest request = new DeleteIndexRequest("user2");
        // 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());
        client.close();
    }
}

后台打印：

操作结果 ： true

Process finished with exit code 0

21-入门-JavaAPI-文档-新增 & 修改

重构

上文由于频繁使用以下连接Elasticsearch和关闭它的代码，于是个人对它进行重构。

public class SomeClass {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));
		
        ...
        
        client.close();
    }
}

重构后的代码：

import org.elasticsearch.client.RestHighLevelClient;

public interface ElasticsearchTask {

    void doSomething(RestHighLevelClient client) throws Exception;

}

public class ConnectElasticsearch{

    public static void connect(ElasticsearchTask task){
        // 创建客户端对象
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));
        try {
            task.doSomething(client);
            // 关闭客户端连接
            client.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

接下来，如果想让Elasticsearch完成一些操作，就编写一个lambda式即可。

public class SomeClass {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
			//do something
        });
    }
}

新增

import com.fasterxml.jackson.databind.ObjectMapper;
import com.lun.elasticsearch.hello.ConnectElasticsearch;
import com.lun.elasticsearch.model.User;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.common.xcontent.XContentType;

public class InsertDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            // 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.setName("zhangsan");
            user.setAge(30);
            user.setSex("男");

            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);
            3.打印结果信息
            System.out.println("_index:" + response.getIndex());
            System.out.println("_id:" + response.getId());
            System.out.println("_result:" + response.getResult());
        });
    }
}

后台打印：

_index:user
_id:1001
_result:UPDATED

Process finished with exit code 0

修改

import com.lun.elasticsearch.hello.ConnectElasticsearch;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.common.xcontent.XContentType;

public class UpdateDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            // 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());
        });
    }

}

后台打印：

_index:user
_id:1001
_result:UPDATED

Process finished with exit code 0

22-入门-JavaAPI-文档-查询 & 删除

查询

import com.lun.elasticsearch.hello.ConnectElasticsearch;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.RequestOptions;

public class GetDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            //1.创建请求对象
            GetRequest request = new GetRequest().index("user").id("1001");
            //2.客户端发送请求，获取响应对象
            GetResponse response = client.get(request, RequestOptions.DEFAULT);
            3.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());
        });
    }
}

后台打印：

_index:user
_type:_doc
_id:1001
source:{"name":"zhangsan","age":30,"sex":"男"}

Process finished with exit code 0

删除

import com.lun.elasticsearch.hello.ConnectElasticsearch;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.client.RequestOptions;

public class DeleteDoc {
    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            //创建请求对象
            DeleteRequest request = new DeleteRequest().index("user").id("1001");
            //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());
        });
    }
}

后台打印：

DeleteResponse[index=user,type=_doc,id=1001,version=16,result=deleted,shards=ShardInfo{total=2, successful=1, failures=[]}]

Process finished with exit code 0

23-入门-JavaAPI-文档-批量新增 & 批量删除

批量新增

import com.lun.elasticsearch.hello.ConnectElasticsearch;
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.common.xcontent.XContentType;

public class BatchInsertDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            //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:" + responses.getItems());
        });
    }
}

后台打印

took:294ms
items:[Lorg.elasticsearch.action.bulk.BulkItemResponse;@2beee7ff

Process finished with exit code 0

批量删除

import com.lun.elasticsearch.hello.ConnectElasticsearch;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.client.RequestOptions;

public class BatchDeleteDoc {
    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            //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:" + responses.getItems());
        });
    }
}

后台打印

took:108ms
items:[Lorg.elasticsearch.action.bulk.BulkItemResponse;@7b02881e

Process finished with exit code 0

24-入门-JavaAPI-文档-高级查询-全量查询

先批量增加数据

public class BatchInsertDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            //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", "age", "10", "sex","女"));
            request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "lisi", "age", "30", "sex","女"));
            request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "wangwu1", "age", "40", "sex","男"));
            request.add(new IndexRequest().index("user").id("1004").source(XContentType.JSON, "name", "wangwu2", "age", "20", "sex","女"));
            request.add(new IndexRequest().index("user").id("1005").source(XContentType.JSON, "name", "wangwu3", "age", "50", "sex","男"));
            request.add(new IndexRequest().index("user").id("1006").source(XContentType.JSON, "name", "wangwu4", "age", "20", "sex","男"));
            //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:" + responses.getItems());
        });
    }
}

后台打印

took:168ms
items:[Lorg.elasticsearch.action.bulk.BulkItemResponse;@2beee7ff

Process finished with exit code 0

查询所有索引数据

import com.lun.elasticsearch.hello.ConnectElasticsearch;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;

public class QueryDoc {

    public static void main(String[] args) {
        ConnectElasticsearch.connect(client -> {
            // 创建搜索请求对象
            SearchRequest request = new SearchRequest();
            request.indices("user");
            // 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("<<========");
        });
    }

}