ES:修改分词器以及定制自己的分词器

1、默认的分词器

standard

standard tokenizer：以单词边界进行切分
standard token filter：什么都不做
lowercase token filter：将所有字母转换为小写
stop token filer（默认被禁用）：移除停用词，比如a the it等等

2、修改分词器的设置

PUT /my_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "es_std": {
          "type": "standard",
          "stopwords": "_english_"
        }
      }
    }
  }
}

3、定制化自己的分词器

PUT /my_index
{
  "settings": {
    "analysis": {
      "char_filter": {
        "&_to_and": {
          "type": "mapping",
          "mappings": [
            "&=> and"
          ]
        }
      },
      "filter": {
        "my_stopwords": {
          "type": "stop",
          "stopwords": [
            "the",
            "a"
          ]
        }
      },
      "analyzer": {
        "my_analyzer": {
          "type": "custom",
          "char_filter": [
            "html_strip",
            "&_to_and"
          ],
          "tokenizer": "standard",
          "filter": [
            "lowercase",
            "my_stopwords"
          ]
        }
      }
    }
  }
}

PUT /my_index/_mapping/my_type
{
  "properties": {
    "content": {
      "type": "text",
      "analyzer": "my_analyzer"
    }
  }
}