原文地址: https://www.elastic.co/guide/en/elasticsearch/reference/7.7/analysis-uppercase-tokenfilter.html, 原文档版权归 www.elastic.co 所有
IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Uppercase token filteredit
Changes token text to uppercase. For example, you can use the uppercase filter
to change the Lazy DoG to THE LAZY DOG.
This filter uses Lucene’s UpperCaseFilter.
Depending on the language, an uppercase character can map to multiple
lowercase characters. Using the uppercase filter could result in the loss of
lowercase character information.
To avoid this loss but still have a consistent letter case, use the
lowercase filter instead.
Exampleedit
The following analyze API request uses the default
uppercase filter to change the the Quick FoX JUMPs to uppercase:
GET _analyze
{
"tokenizer" : "standard",
"filter" : ["uppercase"],
"text" : "the Quick FoX JUMPs"
}
The filter produces the following tokens:
[ THE, QUICK, FOX, JUMPS ]
Add to an analyzeredit
The following create index API request uses the
uppercase filter to configure a new
custom analyzer.
PUT uppercase_example
{
"settings" : {
"analysis" : {
"analyzer" : {
"whitespace_uppercase" : {
"tokenizer" : "whitespace",
"filter" : ["uppercase"]
}
}
}
}
}