Java教程

HM-SpringCloud微服务系列7.2【自动补全】

本文主要是介绍HM-SpringCloud微服务系列7.2【自动补全】,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

自动补全需求说明

当用户在搜索框输入字符时,我们应该提示出与该字符有关的搜索项,如图:
image
这种根据用户输入的字母,提示完整词条的功能,就是自动补全了。
因为需要根据拼音字母来推断,因此要用到拼音分词功能

1 拼音分词器

1.1 拼音分词器介绍

要实现根据字母做补全,就必须对文档按照拼音分词。在GitHub上恰好有elasticsearch的拼音分词插件。地址:https://github.com/medcl/elasticsearch-analysis-pinyin
安装方式与IK分词器一样,分三步:
​ ①解压
​ ②上传到虚拟机中,elasticsearch的plugin目录
​ ③重启elasticsearch
​ ④测试
详细安装步骤可以参考IK分词器的安装过程https://www.cnblogs.com/yppah/p/15936823.html。

1.2 拼音分词器安装

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1.3 测试

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点击查看代码
{
  "tokens" : [
    {
      "token" : "ru",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 0
    },
    {
      "token" : "rjjdhbcm",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 0
    },
    {
      "token" : "jia",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 1
    },
    {
      "token" : "jiu",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 2
    },
    {
      "token" : "dian",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 3
    },
    {
      "token" : "hai",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 4
    },
    {
      "token" : "bu",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 5
    },
    {
      "token" : "cuo",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 6
    },
    {
      "token" : "ma",
      "start_offset" : 0,
      "end_offset" : 0,
      "type" : "word",
      "position" : 7
    }
  ]
}

2 自定义分词器

2.1 默认的拼音分词器

  • 默认的拼音分词器会将每个汉字单独分为拼音,而我们希望的是每个词条形成一组拼音,需要对拼音分词器做个性化定制,形成自定义分词器。
  • elasticsearch中分词器(analyzer)的组成包含三部分:
    • character filters:在tokenizer之前对文本进行处理。例如删除字符、替换字符
    • tokenizer:将文本按照一定的规则切割成词条(term)。例如keyword,就是不分词;还有ik_smart
    • tokenizer filter:将tokenizer输出的词条做进一步处理。例如大小写转换、同义词处理、拼音处理等
  • 文档分词时会依次由这三部分来处理文档:
    • image

2.2 自定义分词器

2.2.1

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点击查看代码
# 自定义拼音分词器
PUT /test
{
  "settings": {
    "analysis": {
      "analyzer": { 
        "my_analyzer": { 
          "tokenizer": "ik_max_word",
          "filter": "py"
        }
      },
      "filter": {
        "py": { 
          "type": "pinyin",
          "keep_full_pinyin": false,
          "keep_joined_full_pinyin": true,
          "keep_original": true,
          "limit_first_letter_length": 16,
          "remove_duplicated_term": true,
          "none_chinese_pinyin_tokenize": false
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "name": {
        "type": "text",
        "analyzer": "my_analyzer"
      }
    }
  }
}


POST /test/_analyze
{
  "text": ["如家酒店还不错"],
  "analyzer": "my_analyzer"
}
点击查看代码
{
  "tokens" : [
    {
      "token" : "如家",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "rujia",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "rj",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "酒店",
      "start_offset" : 2,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "jiudian",
      "start_offset" : 2,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "jd",
      "start_offset" : 2,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "还不",
      "start_offset" : 4,
      "end_offset" : 6,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "haibu",
      "start_offset" : 4,
      "end_offset" : 6,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "hb",
      "start_offset" : 4,
      "end_offset" : 6,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "不错",
      "start_offset" : 5,
      "end_offset" : 7,
      "type" : "CN_WORD",
      "position" : 3
    },
    {
      "token" : "bucuo",
      "start_offset" : 5,
      "end_offset" : 7,
      "type" : "CN_WORD",
      "position" : 3
    },
    {
      "token" : "bc",
      "start_offset" : 5,
      "end_offset" : 7,
      "type" : "CN_WORD",
      "position" : 3
    }
  ]
}

2.2.2

POST /test/_doc/1
{
  "id": 1,
  "name": "狮子"
}
POST /test/_doc/2
{
  "id": 2,
  "name": "虱子"
}

GET /test/_search
{
  "query": {
    "match": {
      "name": "掉入狮子笼咋办"
    }
  }
}

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ok

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?

原因分析
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解决办法
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解决
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image
ok

2.3 小结

  1. 如何使用拼音分词器?
    • ①下载pinyin分词器
    • ②解压并放到elasticsearch的plugin目录
    • ③重启即可
  2. 如何自定义分词器?
    • ①创建索引库时,在settings中配置,可以包含三部分
    • ②character filter
    • ③tokenizer
    • ④filter
  3. 拼音分词器注意事项?
    • 为了避免搜索到同音字,搜索时不要使用拼音分词器

3 自动补全查询

  • elasticsearch提供了Completion Suggester查询来实现自动补全功能。这个查询会匹配以用户输入内容开头的词条并返回。为了提高补全查询的效率,对于文档中字段的类型有一些约束:
    • 参与补全查询的字段必须是completion类型。
    • 字段的内容一般是用来补全的多个词条形成的数组
  • 比如,一个这样的索引库:
# 创建索引库
PUT test2
{
  "mappings": {
    "properties": {
      "title":{
        "type": "completion"
      }
    }
  }
}
  • 然后插入下面的数据:
# 示例数据
POST test2/_doc
{
  "title": ["Sony", "WH-1000XM3"]
}
POST test2/_doc
{
  "title": ["SK-II", "PITERA"]
}
POST test2/_doc
{
  "title": ["Nintendo", "switch"]
}
  • 查询的DSL语句如下:
# 自动补全查询
GET /test2/_search
{
  "suggest": {
    "title_suggest": {
      "text": "s", # 关键字
      "completion": {
        "field": "title", # 补全查询的字段
        "skip_duplicates": true, # 跳过重复的
        "size": 10 # 获取前10条结果
      }
    }
  }
}
  • 测试
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点击查看代码
{
  "took" : 565,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "suggest" : {
    "title_suggest" : [
      {
        "text" : "s",
        "offset" : 0,
        "length" : 1,
        "options" : [
          {
            "text" : "SK-II",
            "_index" : "test2",
            "_type" : "_doc",
            "_id" : "xuqv2n8BUtPonQDctNZG",
            "_score" : 1.0,
            "_source" : {
              "title" : [
                "SK-II",
                "PITERA"
              ]
            }
          },
          {
            "text" : "Sony",
            "_index" : "test2",
            "_type" : "_doc",
            "_id" : "xeqv2n8BUtPonQDcS9aX",
            "_score" : 1.0,
            "_source" : {
              "title" : [
                "Sony",
                "WH-1000XM3"
              ]
            }
          },
          {
            "text" : "switch",
            "_index" : "test2",
            "_type" : "_doc",
            "_id" : "x-qv2n8BUtPonQDcyNYX",
            "_score" : 1.0,
            "_source" : {
              "title" : [
                "Nintendo",
                "switch"
              ]
            }
          }
        ]
      }
    ]
  }
}

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4 实现酒店搜索框自动补全

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  • 现在,我们的hotel索引库还没有设置拼音分词器,需要修改索引库中的配置。但是我们知道索引库是无法修改的,只能删除然后重新创建。
  • 另外,我们需要添加一个字段,用来做自动补全,将brand、suggestion、city等都放进去,作为自动补全的提示。

4.1 修改酒店映射结构

4.1.1 查看酒店数据原索引表

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4.1.2 修改酒店索引表

点击查看代码
# 酒店数据索引库
PUT /hotel
{
  "settings": {
    "analysis": {
      "analyzer": {
        "text_anlyzer": {
          "tokenizer": "ik_max_word",
          "filter": "py"
        },
        "completion_analyzer": {
          "tokenizer": "keyword",
          "filter": "py"
        }
      },
      "filter": {
        "py": {
          "type": "pinyin",
          "keep_full_pinyin": false,
          "keep_joined_full_pinyin": true,
          "keep_original": true,
          "limit_first_letter_length": 16,
          "remove_duplicated_term": true,
          "none_chinese_pinyin_tokenize": false
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "id":{
        "type": "keyword"
      },
      "name":{
        "type": "text",
        "analyzer": "text_anlyzer",
        "search_analyzer": "ik_smart",
        "copy_to": "all"
      },
      "address":{
        "type": "keyword",
        "index": false
      },
      "price":{
        "type": "integer"
      },
      "score":{
        "type": "integer"
      },
      "brand":{
        "type": "keyword",
        "copy_to": "all"
      },
      "city":{
        "type": "keyword"
      },
      "starName":{
        "type": "keyword"
      },
      "business":{
        "type": "keyword",
        "copy_to": "all"
      },
      "location":{
        "type": "geo_point"
      },
      "pic":{
        "type": "keyword",
        "index": false
      },
      "all":{
        "type": "text",
        "analyzer": "text_anlyzer",
        "search_analyzer": "ik_smart"
      },
      "suggestion":{
          "type": "completion",
          "analyzer": "completion_analyzer"
      }
    }
  }
}

text_anlyzer用于全文检索
completion_analyzer用于自动补全,它采用keyword分词器(即不分词)然后转为拼音

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4.2 修改HotelDoc实体

  • HotelDoc中要添加一个字段,用来做自动补全,内容可以是酒店品牌、城市、商圈等信息。按照自动补全字段的要求,最好是这些字段的数组。
  • 因此我们在HotelDoc中添加一个suggestion字段,类型为List<String>,然后将brand、city、business等信息放到里面。
    image
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点击查看代码
package com.yppah.hoteldemo.pojo;

import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

@Data
@NoArgsConstructor
public class HotelDoc {
    private Long id;
    private String name;
    private String address;
    private Integer price;
    private Integer score;
    private String brand;
    private String city;
    private String starName;
    private String business;
    private String location;
    private String pic;

    private Object distance;
    private Boolean isAD;
//    private String isAD;
    private List<String> suggestion; //存储给用户自动补全的内容

    public HotelDoc(Hotel hotel) {
        this.id = hotel.getId();
        this.name = hotel.getName();
        this.address = hotel.getAddress();
        this.price = hotel.getPrice();
        this.score = hotel.getScore();
        this.brand = hotel.getBrand();
        this.city = hotel.getCity();
        this.starName = hotel.getStarName();
        this.business = hotel.getBusiness();
        this.location = hotel.getLatitude() + ", " + hotel.getLongitude();
        this.pic = hotel.getPic();

        // 组装suggestion
//        this.suggestion = Arrays.asList(this.brand, this.business);
        if(this.business.contains("、")){
            // business有多个值,需要切割
            String[] arr = this.business.split("、");
            // 添加元素
            this.suggestion = new ArrayList<>();
            this.suggestion.add(this.brand);
            Collections.addAll(this.suggestion, arr); //Collections.addAll批量添加
        }else {
            this.suggestion = Arrays.asList(this.brand, this.business);
        }
    }
}

4.3 重新批量导入酒店数据

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测试
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GET /hotel/_search
{
  "suggest": {
    "suggestions": {
      "text": "h",
      "completion": {
        "field": "suggestion",
        "skip_duplicates": true,
        "size": 5
      }
    }
  }
}
点击查看代码
{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "suggest" : {
    "suggestions" : [
      {
        "text" : "h",
        "offset" : 0,
        "length" : 1,
        "options" : [
          {
            "text" : "和颐",
            "_index" : "hotel",
            "_type" : "_doc",
            "_id" : "416268",
            "_score" : 1.0,
            "_source" : {
              "address" : "朝阳路高井176号",
              "brand" : "和颐",
              "business" : "国贸地区",
              "city" : "北京",
              "id" : 416268,
              "location" : "39.918277, 116.53015",
              "name" : "和颐酒店(北京传媒大学财满街店)",
              "pic" : "https://m.tuniucdn.com/fb2/t1/G6/M00/52/13/Cii-TF3eP5GIJIOLAAUwsIVCxdAAAGKXgK5a0IABTDI239_w200_h200_c1_t0.jpg",
              "price" : 524,
              "score" : 46,
              "starName" : "三钻",
              "suggestion" : [
                "和颐",
                "国贸地区"
              ]
            }
          },
          {
            "text" : "汉庭",
            "_index" : "hotel",
            "_type" : "_doc",
            "_id" : "607915",
            "_score" : 1.0,
            "_source" : {
              "address" : "滨河大道6033号海滨广场国皇大厦3楼",
              "brand" : "汉庭",
              "business" : "皇岗口岸/福田口岸",
              "city" : "深圳",
              "id" : 607915,
              "location" : "22.528101, 114.064221",
              "name" : "汉庭酒店(深圳皇岗店)",
              "pic" : "https://m.tuniucdn.com/fb3/s1/2n9c/qMyCJVYuW21nsCeEBt8CMfmEhra_w200_h200_c1_t0.jpg",
              "price" : 313,
              "score" : 42,
              "starName" : "二钻",
              "suggestion" : [
                "汉庭",
                "皇岗口岸/福田口岸"
              ]
            }
          },
          {
            "text" : "海岸城/后海",
            "_index" : "hotel",
            "_type" : "_doc",
            "_id" : "1406627919",
            "_score" : 1.0,
            "_source" : {
              "address" : "海德一道88号中洲控股中心A座",
              "brand" : "万豪",
              "business" : "海岸城/后海",
              "city" : "深圳",
              "id" : 1406627919,
              "location" : "22.517293, 113.933785",
              "name" : "深圳中洲万豪酒店",
              "pic" : "https://m.tuniucdn.com/fb3/s1/2n9c/3wsinQAcuWtCdmv1yxauVG2PSYpC_w200_h200_c1_t0.jpg",
              "price" : 204,
              "score" : 47,
              "starName" : "五钻",
              "suggestion" : [
                "万豪",
                "海岸城/后海"
              ]
            }
          },
          {
            "text" : "皇冠假日",
            "_index" : "hotel",
            "_type" : "_doc",
            "_id" : "56392",
            "_score" : 1.0,
            "_source" : {
              "address" : "番禺路400号",
              "brand" : "皇冠假日",
              "business" : "徐家汇地区",
              "city" : "上海",
              "id" : 56392,
              "location" : "31.202768, 121.429524",
              "name" : "上海银星皇冠假日酒店",
              "pic" : "https://m.tuniucdn.com/fb3/s1/2n9c/37ucQ38K3UFdcRqntJ8M5dt884HR_w200_h200_c1_t0.jpg",
              "price" : 809,
              "score" : 47,
              "starName" : "五星级",
              "suggestion" : [
                "皇冠假日",
                "徐家汇地区"
              ]
            }
          },
          {
            "text" : "豪生",
            "_index" : "hotel",
            "_type" : "_doc",
            "_id" : "45870",
            "_score" : 1.0,
            "_source" : {
              "address" : "新元南路555号",
              "brand" : "豪生",
              "business" : "滴水湖临港地区",
              "city" : "上海",
              "id" : 45870,
              "location" : "30.871729, 121.81959",
              "name" : "上海临港豪生大酒店",
              "pic" : "https://m.tuniucdn.com/fb3/s1/2n9c/2F5HoQvBgypoDUE46752ppnQaTqs_w200_h200_c1_t0.jpg",
              "price" : 896,
              "score" : 45,
              "starName" : "四星级",
              "suggestion" : [
                "豪生",
                "滴水湖临港地区"
              ]
            }
          }
        ]
      }
    ]
  }
}

至此,基于DSL的酒店数据自动补全功能已实现(以拼音方式)

4.4 自动补全查询的JavaAPI

4.4.1

  • 之前我们学习了自动补全查询的DSL,而没有学习对应的JavaAPI,这里给出一个示例:
    image
  • 测试
    image
    image
    	@Test
    	void testSuggestion() throws IOException {
    		// 1. 准备request
    		SearchRequest request = new SearchRequest("hotel");
    
    		// 2. 准备DSL
    		request.source().suggest(new SuggestBuilder().addSuggestion(
    				"suggestions",
    				SuggestBuilders.completionSuggestion("suggestion")
    					.prefix("h")
    					.skipDuplicates(true)
    					.size(5)
    		));
    
    		// 3. 发起请求
    		SearchResponse response = client.search(request, RequestOptions.DEFAULT);
    
    		// 4. 解析响应
    		System.out.println(response);
    	}
    

4.4.2

  • 而自动补全的结果也比较特殊,解析的代码如下:
    image

  • 测试
    image
    image

    点击查看代码
    	@Test
    	void testSuggestion() throws IOException {
    		// 1. 准备request
    		SearchRequest request = new SearchRequest("hotel");
    
    		// 2. 准备DSL
    		request.source().suggest(new SuggestBuilder().addSuggestion(
    				"suggestions",
    				SuggestBuilders.completionSuggestion("suggestion")
    					.prefix("h")
    					.skipDuplicates(true)
    					.size(5)
    		));
    
    		// 3. 发起请求
    		SearchResponse response = client.search(request, RequestOptions.DEFAULT);
    
    		// 4. 解析响应
    //        System.out.println(response);
    		Suggest suggest = response.getSuggest();
    		// 4.1 根据补全查询名称获取补全结果
    		CompletionSuggestion suggentions = suggest.getSuggestion("suggestions");
    		// 4.2 获取options
    		List<CompletionSuggestion.Entry.Option> options = suggentions.getOptions();
    		// 4.3 遍历options
    		for (CompletionSuggestion.Entry.Option option: options) {
    			String text = option.getText().toString();
    			System.out.println(text);
    		}
    	}
    

4.5 实现搜索框自动补全

  • 查看前端页面,可以发现当我们在输入框键入时,前端会发起ajax请求:
    image
    image
  • 返回值是补全词条的集合,类型为List<String>

4.5.1 HotelController

    @GetMapping("suggestion")
    public List<String> getSuggestion(@RequestParam("key") String prefix) {
        return hotelService.getSuggestion(prefix);
    }

image

4.5.2 IhotelService

    List<String> getSuggestion(String prefix);

image

4.5.3 HotelService

点击查看代码
    // 参考HotelSearchTest的testAggregation()
    @Override
    public List<String> getSuggestion(String prefix) {
        //ctrl+alt+t快捷键,利用trycatch或者其他将目标代码块包含起来
        try {
            // 1. 准备request
            SearchRequest request = new SearchRequest("hotel");

            // 2. 准备DSL
            request.source().suggest(new SuggestBuilder().addSuggestion(
                    "suggestions",
                    SuggestBuilders.completionSuggestion("suggestion")
                            .prefix(prefix)
                            .skipDuplicates(true)
                            .size(5)
            ));

            // 3. 发起请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);

            // 4. 解析响应
//        System.out.println(response);
            Suggest suggest = response.getSuggest();
            // 4.1 根据补全查询名称获取补全结果
            CompletionSuggestion suggentions = suggest.getSuggestion("suggestions");
            // 4.2 获取options
            List<CompletionSuggestion.Entry.Option> options = suggentions.getOptions();
            // 4.3 遍历options
            List<String> resList = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option: options) {
                String text = option.getText().toString();
                resList.add(text);
            }
            return resList;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

image

4.5.4 重启服务测试

image
image

至此,自动补全和拼音搜索功能均已实现

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