[TOC]
本连接器只提供了基本的数据上传、查询和删除操作，但ElasticSearch是一个庞大而复杂的搜索引擎，要完全理解、掌握和使用也不是一蹴而就的事情。它提供了丰富的REST API，我们的连接器不可能完全满足您的需求，所以再此前提下，我们提供了该接入点用于执行elastic的API。
ElasticSearch的REST APIs，请参考：
[https://www.elastic.co/guide/en/elasticsearch/reference/current/rest-apis.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/rest-apis.html "https://www.elastic.co/guide/en/elasticsearch/reference/current/rest-apis.html")
在本接入点下，我们演示一个常用的分页查询+高亮显示的例子来给大家说明，如果使用我们的“执行ES语句”接入点。
# 1.插入数据:
利用2.2中说明的保存操作，我们插入以下内容(java代码)：
```java
String res1=new ShowApiRequest("http://route.showapi.com/2161-2","my_appId","my_appSecret")
.addTextPara("data","{\"id_card\":\"1\",\"name\":\"张三\",\"age\":23,\"hobbies\":\"足球 看书\"}")
.addTextPara("id_field","id_card")
.post();
//=============================================
String res2=new ShowApiRequest("http://route.showapi.com/2161-2","my_appId","my_appSecret")
.addTextPara("data","{\"id_card\":\"2\",\"name\":\"李四\",\"age\":21,\"hobbies\":\"画画、音乐、足球\"}")
.addTextPara("id_field","id_card")
.post();
//=============================================
String res3=new ShowApiRequest("http://route.showapi.com/2161-2","my_appId","my_appSecret")
.addTextPara("data","{\"id_card\":\"3\",\"name\":\"王五\",\"age\":28,\"hobbies\":\"足球、钢琴、武术\"}")
.addTextPara("id_field","id_card")
.post();
//=============================================
String res4=new ShowApiRequest("http://route.showapi.com/2161-2","my_appId","my_appSecret")
.addTextPara("data","{\"id_card\":\"4\",\"name\":\"隔壁老王\",\"age\":36,\"hobbies\":\"足球、看书、书法、象棋、炒股\"}")
.addTextPara("id_field","id_card")
.post();
//=============================================
String res5=new ShowApiRequest("http://route.showapi.com/2161-2","my_appId","my_appSecret")
.addTextPara("data","{\"id_card\":\"5\",\"name\":\"小明\",\"age\":17,\"hobbies\":\"足球、篮球、唱歌、书法\"}")
.addTextPara("id_field","id_card")
.post();
```
# 2.编写语句
首先查询一个简单的语句,比如我们来查询一下年纪小于等于22岁,大于等于10岁的人有哪些,那这个语句怎么写呢?参考以下语句:
```css
GET /common_index/_search
{
"query": {
"range": {
"age": {
"gte": 10,
"lte": 22
}
}
}
}
```
那么我们的连接器接口怎么操作呢?请看如下(JAVA)代码:
```java
String script = "{\n" +
" \"query\": {\n" +
" \"range\": {\n" +
" \"age\": {\n" +
" \"gte\": 10,\n" +
" \"lte\": 22\n" +
" }\n" +
" }\n" +
" }\n" +
" }";
String res=new ShowApiRequest("http://route.showapi.com/2161-4","my_appId","my_appSecret")
.addTextPara("exec_json",script)
.addTextPara("op_type","1")//数据提交的HTTP方式,比如删除操作用3,具体取值如下：1:get 2:post 3:delete 4:put 5:head
.addTextPara("url","/common_index/_search")
.post();
System.out.println(res);
```
返回的数据:
```css
{
"showapi_res_error": "",
"showapi_res_code": 0,
"showapi_res_id": "5894eabdd8a043d1bda4ddb813d84441",
"showapi_res_body": {
"_shards": {
"total": 1,
"skipped": 0,
"failed": 0,
"successful": 1
},
"hits": {
"total": {
"value": 2,
"relation": "eq"
},
"hits": [
{
"_type": "_doc",
"_id": "2",
"_source": {
"age": 21,
"name": "李四",
"hobbies": "画画、音乐、足球"
},
"_index": "common_index",
"_score": 1
},
{
"_type": "_doc",
"_id": "5",
"_source": {
"age": 17,
"name": "小明",
"hobbies": "足球、篮球、唱歌、书法"
},
"_index": "common_index",
"_score": 1
}
],
"max_score": 1
},
"ret_code": 0,
"timed_out": false,
"remark": "操作已执行，结果请参考相应返回信息。",
"took": 2
}
}
```
------------
上述例子较为简单，我们现在说一个稍微复杂点的例子。
我们经常有查询+分页显示的需求,比如我们想了解下爱好足球但是不喜欢武术和炒股的人有哪些。根据这个需求，我们来编写elastic的查询语句，语句如下：
```css
GET /common_index/_search
{
"query": {
"simple_query_string" : {
"fields" : ["hobbies"],
"query" : "+足球 -武术 -炒股",
"default_operator": "AND"
}
},
"from": 0,
"size": 10
}
```
代码参考第一个例子,如下:
```java
String script = "{\n" +
" \"query\": {\n" +
" \"simple_query_string\" : {\n" +
" \"fields\" : [\"hobbies\"],\n" +
" \"query\" : \"+足球 -武术 -炒股\",\n" +
" \"default_operator\": \"AND\"\n" +
" }\n" +
" },\n" +
" \"from\": 0,\n" +
" \"size\": 10\n" +
"}";
String res=new ShowApiRequest("http://route.showapi.com/2161-4","my_appId","my_appSecret")
.addTextPara("exec_json",script)
.addTextPara("op_type","1")//数据提交的HTTP方式,比如删除操作用3,具体取值如下：1:get 2:post 3:delete 4:put 5:head
.addTextPara("url","/common_index/_search")
.post();
System.out.println(res);
```
返回结果:
```css
{
"showapi_res_error": "",
"showapi_res_code": 0,
"showapi_res_id": "18837d4ff9d744bda43d6f926f0c4177",
"showapi_res_body": {
"_shards": {
"total": 1,
"skipped": 0,
"failed": 0,
"successful": 1
},
"hits": {
"total": {
"value": 3,
"relation": "eq"
},
"hits": [
{
"_type": "_doc",
"_id": "1",
"_source": {
"age": 23,
"name": "张三",
"hobbies": "足球 看书"
},
"_index": "common_index",
"_score": 2.209275
},
{
"_type": "_doc",
"_id": "5",
"_source": {
"age": 17,
"name": "小明",
"hobbies": "足球、篮球、唱歌、书法"
},
"_index": "common_index",
"_score": 2.195136
},
{
"_type": "_doc",
"_id": "2",
"_source": {
"age": 21,
"name": "李四",
"hobbies": "画画、音乐、足球"
},
"_index": "common_index",
"_score": 2.1828218
}
],
"max_score": 2.209275
},
"ret_code": 0,
"timed_out": false,
"remark": "操作已执行，结果请参考相应返回信息。",
"took": 2
}
}
```
------------
再说一个常用的需求"高亮显示"。根据以上的说明，我们实现一个查询+分页+代码高亮显示的代码，需求如下：查询喜欢书籍或者足球的用户有哪些，请分页显示，每页最多5条数据？ 由于高亮显示中需要对字符进行分词、长度计算，而我们提供的测试用的ElasticSearch7.4.2是没有安装中文分词器的，所以在查询中文信息的时候进行高亮会执行错误。为避免错误的发生，所以在演示代码操作之前，我们把数据调整一下，主要是把爱好的中文文字调整成英文的，其他信息不变，具体调整如下：
```css
[
{
"_id": "1",
"name": "张三",
"age": 23,
"hobbies": "football book"
},
{
"_id": "2",
"name": "李四",
"age": 21,
"hobbies": "art music football"
},
{
"_id": "3",
"name": "王五",
"age": 28,
"hobbies": "football piano kongfu"
},
{
"_id": "4",
"name": "隔壁老王",
"age": 36,
"hobbies": "football book calligraphy chess stocks"
},
{
"_id": "5",
"name": "小明",
"age": 17,
"hobbies": "football basketball sing calligraphy"
}
]
```
根据这个需求，我们来编写elastic的查询语句，语句如下：
```css
GET /common_index/_search
{
"query": {
"match": {
"hobbies": "book football"
}
},
"highlight": {
"pre_tags": ["<h3>"],
"post_tags": ["</h3>"],
"fields": {
"hobbies": {}
}
},
"from": 0,
"size": 5
}
```
Java操作的代码如下:
```java
String script = "{\n" +
" \"query\": {\n" +
" \"match\": {\n" +
" \"hobbies\": \"book football\"\n" +
" }\n" +
" },\n" +
" \"highlight\": {\n" +
" \"pre_tags\": [\"<h3>\"],\n" +
" \"post_tags\": [\"</h3>\"],\n" +
" \"fields\": {\n" +
" \"hobbies\": {}\n" +
" }\n" +
" },\n" +
" \"from\": 0,\n" +
" \"size\": 5\n" +
"}";
String res=new ShowApiRequest("http://route.showapi.com/2161-4","my_appId","my_appSecret")
.addTextPara("exec_json",script)
.addTextPara("op_type","1") //1:get 2:post 3:delete 4:put 5:head
.addTextPara("url","/common_index/_search")
.post();
System.out.println(res);
```
返回的数据：
```css
{
"showapi_res_error": "",
"showapi_res_code": 0,
"showapi_res_id": "a1f9de9ed6df44ec9c5d1f12496f6d0c",
"showapi_res_body": {
"_shards": {
"total": 1,
"skipped": 0,
"failed": 0,
"successful": 1
},
"hits": {
"total": {
"value": 5,
"relation": "eq"
},
"hits": [
{
"_type": "_doc",
"_id": "1",
"_source": {
"age": 23,
"name": "张三",
"hobbies": "football book"
},
"_index": "common_index",
"_score": 1.7232791,
"highlight": {
"hobbies": [
"<h3>football</h3> <h3>book</h3>"
]
}
},
{
"_type": "_doc",
"_id": "4",
"_source": {
"age": 36,
"name": "隔壁老王",
"hobbies": "football book calligraphy chess stocks"
},
"_index": "common_index",
"_score": 1.2436035,
"highlight": {
"hobbies": [
"<h3>football</h3> <h3>book</h3> calligraphy chess stocks"
]
}
},
{
"_type": "_doc",
"_id": "3",
"_source": {
"age": 28,
"name": "王五",
"hobbies": "football piano Kongfu"
},
"_index": "common_index",
"_score": 0.2312945,
"highlight": {
"hobbies": [
"<h3>football</h3> piano Kongfu"
]
}
},
{
"_type": "_doc",
"_id": "2",
"_source": {
"age": 21,
"name": "李四",
"hobbies": "art music football"
},
"_index": "common_index",
"_score": 0.2312945,
"highlight": {
"hobbies": [
"art music <h3>football</h3>"
]
}
},
{
"_type": "_doc",
"_id": "5",
"_source": {
"age": 17,
"name": "小明",
"hobbies": "football basketball sing calligraphy"
},
"_index": "common_index",
"_score": 0.20763937,
"highlight": {
"hobbies": [
"<h3>football</h3> basketball sing calligraphy"
]
}
}
],
"max_score": 1.7232791
},
"ret_code": 0,
"timed_out": false,
"remark": "操作已执行，结果请参考相应返回信息。",
"took": 6
}
}
```
根据以上的返回我们可以看到“爱好”字段中，只要包含book和football两项之一的，都会进行返回并高亮显示，并有打分_score，完全满足了我们的需求。
以上的操作是针对查询的，因为search是我们最常用、最关注的操作。您也可以进行其他操作，如删除数据、更改映射、滚动查询、统计等等。