简单分词器

简单分词器 #

简单(simple)分词器是一种非常基础的分词器,它会将文本中的非字母字符串拆分成词项,并将这些词项转换为小写形式。与标准分词器不同的是,简单分词器将除字母字符之外的所有内容都视为分隔符,这意味着它不会把数字、标点符号或特殊字符识别为词元的一部分。

参考样例 #

以下命令创建一个名为 my_simple_index 并使用简单分词器的索引:

PUT /my_simple_index
{
  "mappings": {
    "properties": {
      "my_field": {
        "type": "text",
        "analyzer": "simple"
      }
    }
  }
}

配置自定义分词器 #

以下命令配置了一个索引,该索引带有一个自定义分词器,这个自定义分词器等同于添加了 html_strip 字符过滤器的简单分词器:

PUT /my_custom_simple_index
{
  "settings": {
    "analysis": {
      "char_filter": {
        "html_strip": {
          "type": "html_strip"
        }
      },
      "tokenizer": {
        "my_lowercase_tokenizer": {
          "type": "lowercase"
        }
      },
      "analyzer": {
        "my_custom_simple_analyzer": {
          "type": "custom",
          "char_filter": ["html_strip"],
          "tokenizer": "my_lowercase_tokenizer",
          "filter": ["lowercase"]
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "my_field": {
        "type": "text",
        "analyzer": "my_custom_simple_analyzer"
      }
    }
  }
}

产生的词元 #

以下请求用来检查分词器生成的词元:

POST /my_custom_simple_index/_analyze
{
  "analyzer": "my_custom_simple_analyzer",
  "text": "<p>The slow turtle swims over to dogs &copy; 2024!</p>"
}

返回内容中包含了产生的词元

{
  "tokens": [
    {"token": "the","start_offset": 3,"end_offset": 6,"type": "word","position": 0},
    {"token": "slow","start_offset": 7,"end_offset": 11,"type": "word","position": 1},
    {"token": "turtle","start_offset": 12,"end_offset": 18,"type": "word","position": 2},
    {"token": "swims","start_offset": 19,"end_offset": 24,"type": "word","position": 3},
    {"token": "over","start_offset": 25,"end_offset": 29,"type": "word","position": 4},
    {"token": "to","start_offset": 30,"end_offset": 32,"type": "word","position": 5},
    {"token": "dogs","start_offset": 33,"end_offset": 37,"type": "word","position": 6}
  ]
}