es 安装拼音分词器 以及使用

1.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：GitHub - medcl/elasticsearch-analysis-pinyin: This Pinyin Analysis plugin is used to do conversion between Chinese characters and Pinyin.https://github.com/medcl/elasticsearch-analysis-pinyin

2.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

3.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

PUT /test
{
  "settings": {
    "analysis": {
      "analyzer": { // 自定义分词器
        "my_analyzer": {  // 分词器名称
          "tokenizer": "ik_max_word",
          "filter": "py"
        }
      },
      "filter": { // 自定义tokenizer filter
        "py": { // 过滤器名称
          "type": "pinyin", // 过滤器类型，这里是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
        }
      }
    }
  }
}

示例：

#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"
      }
    }
  }
}

但是此时出现中文拼音相同的情况，出现其它搜索结果，因此

拼音分词器适合在创建倒排索引的时候使用，但不能在搜索的时候使用。

创建倒排索引时：

 改正：

在mappings的name中添加  "search_analyzer": "ik_smart"

DELETE /test


#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",
        "search_analyzer": "ik_smart"
      }
    }
  }
}

# 分词器使用验证
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"
    }
  }
}

结果：

{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.9530773,
    "hits" : [
      {
        "_index" : "test",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.9530773,
        "_source" : {
          "id" : 1,
          "name" : "狮子"
        }
      }
    ]
  }
}