nested嵌套对象无法使用ik分词器使用的还是默认分词器，怎么解决

索引类似这种结构
{
"look" : {
"aliases" : { },
"mappings" : {
"properties" : {
"id" : {
"type" : "long"
},
"jpPublishState" : {
"type" : "long"
},
"lookItemsEsPOList" : {
"type" : "nested",
"properties" : {
"brandName" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 512
}
},
"analyzer" : "ik-index"
},
"name" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 512
}
},
"analyzer" : "ik-index"
}
}
},
"viewsNum" : {
"type" : "long"
}
}
},
"settings" : {
"index" : {
"number_of_shards" : "1",
"provided_name" : "look",
"creation_date" : "1574522444689",
"analysis" : {
"analyzer" : {
"ik-index" : {
"char_filter" : [
"html_strip"
],
"type" : "custom",
"tokenizer" : "ik_max_word"
},
"ik-search" : {
"char_filter" : [
"html_strip"
],
"type" : "custom",
"tokenizer" : "ik_smart"
}
}
},
"number_of_replicas" : "1",
"uuid" : "GsCp_ipMS_SIAYZSssxm3A",
"version" : {
"created" : "7010099"
}
}
}
}
}