# Lowercase Tokenizer (小写分词器)

**`lowercase`**** tokenizer**(小写分词器)，类似于  **[`letter` tokenizer](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-letter-tokenizer.html "Letter Tokenizer") **，遇到非字母时分割文本，并将所有分割后的词元转为小写。功能上等同于 ** [`letter` tokenizer](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-letter-tokenizer.html "Letter Tokenizer")** +  **[`lowercase` token filter](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-lowercase-tokenfilter.html "Lowercase Token Filter")** ，但是由于单次执行了所有步骤，所以效率更高。

原文链接 : [https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-lowercase-tokenizer.html](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-lowercase-tokenizer.html)

译文链接 : [http://www.apache.wiki/pages/viewpage.action?pageId=10028862](http://www.apache.wiki/pages/viewpage.action?pageId=10028862)

贡献者 : [陈益雷](/display/~chenyilei)，[ApacheCN](/display/~apachecn)，[Apache中文网](/display/~apachechina)

## **输出示例**

```
POST _analyze
{
  "tokenizer": "lowercase",
  "text": "The 2 QUICK Brown-Foxes jumped over the lazy dog's bone."
}
```

上面的句子会生成如下的词元:

```
[ the, quick, brown, foxes, jumped, over, the, lazy, dog, s, bone ]
```

## **配置**

**`lowercase`**** tokenizer**(小写分词器) 不支持配置。