世界上并没有完美的程序，但是我们并不因此而沮丧，因为写程序就是一个不断追求完美的过程。
自定义分析器 :
- Character filters :
1. 作用 : 字符的增、删、改转换
2. 数量限制 : 可以有0个或多个
3. 内建字符过滤器 :
1. HTML Strip Character filter : 去除html标签
2. Mapping Character filter : 映射替换
3. Pattern Replace Character filter : 正则替换 - Tokenizer :
1. 作用 :
1. 分词
2. 记录词的顺序和位置（短语查询）
3. 记录词的开头和结尾位置（高亮）
4. 记录词的类型（分类）
2. 数量限制 : 有且只能有一个
3. 分类 :
1. 完整分词 :
1. Standard
2. Letter
3. Lowercase
4. whitespace
5. UAX URL Email
6. Classic
7. Thai
2. 切词 :
1. N-Gram
2. Edge N-Gram
3. 文本 :
1. Keyword
2. Pattern
3. Simple Pattern
4. Char Group
5. Simple Pattern split
6. Path - Token filters :
1. 作用 : 分词的增、删、改转换
2. 数量限制 : 可以有0个或多个
3. 分类 :
1. apostrophe
2. asciifolding
3. cjk bigram
4. cjk width
5. classic
6. common grams
7. conditional
8. decimal digit
今天演示内容中 ：
- common grams token filter
- conditional token filter
- 重点关注。
# classic token filter
# 作用 :
# 1. 删除'及后面字符
# 2. 删除缩写间的点
# 适用 : classic分词器
GET /_analyze
{
"tokenizer": "classic",
"filter": ["classic"],
"text": ["hello this is hi's good H.J.K.M. Q.U.I.C.K. "]
}
# 结果
{
"tokens" : [
{
"token" : "hello",
"start_offset" : 0,
"end_offset" : 5,
"type" : "<ALPHANUM>",
"position" : 0
},
{
"token" : "this",
"start_offset" : 6,
"end_offset" : 10,
"type" : "<ALPHANUM>",
"position" : 1
},
{
"token" : "is",
"start_offset" : 11,
"end_offset" : 13,
"type" : "<ALPHANUM>",
"position" : 2
},
{
"token" : "hi",
"start_offset" : 14,
"end_offset" : 18,
"type" : "<APOSTROPHE>",
"position" : 3
},
{
"token" : "good",
"start_offset" : 19,
"end_offset" : 23,
"type" : "<ALPHANUM>",
"position" : 4
},
{
"token" : "HJKM",
"start_offset" : 24,
"end_offset" : 32,
"type" : "<ACRONYM>",
"position" : 5
},
{
"token" : "QUICK",
"start_offset" : 33,
"end_offset" : 43,
"type" : "<ACRONYM>",
"position" : 6
}
]
}
# common grams token filter
# 作用 :
# 1. 指定的词与前后词结合
# 2. 可以避免停用词造成的损失
# 配置项 :
# 1. common_words : 要结合的词
# 2. common_words_path : 要结合词的路径
# 3. ignore_case : 忽略大小写，默认false
# 4. query_mode : 是否单独显示指定的结合的词，默认false - 显示
GET /_analyze
{
"tokenizer": "standard",
"filter": [{
"type" : "common_grams",
"common_words" : ["是", "的", "Is"],
"ignore_case" : true,
"query_mode" : true
}],
"text": ["我是中国人", "这是我的饭", "this is my food"]
}
# 结果
{
"tokens" : [
{
"token" : "我_是",
"start_offset" : 0,
"end_offset" : 2,
"type" : "gram",
"position" : 0
},
{
"token" : "是_中",
"start_offset" : 1,
"end_offset" : 3,
"type" : "gram",
"position" : 1
},
{
"token" : "中",
"start_offset" : 2,
"end_offset" : 3,
"type" : "<IDEOGRAPHIC>",
"position" : 2
},
{
"token" : "国",
"start_offset" : 3,
"end_offset" : 4,
"type" : "<IDEOGRAPHIC>",
"position" : 3
},
{
"token" : "人",
"start_offset" : 4,
"end_offset" : 5,
"type" : "<IDEOGRAPHIC>",
"position" : 4
},
{
"token" : "这_是",
"start_offset" : 6,
"end_offset" : 8,
"type" : "gram",
"position" : 105
},
{
"token" : "是_我",
"start_offset" : 7,
"end_offset" : 9,
"type" : "gram",
"position" : 106
},
{
"token" : "我_的",
"start_offset" : 8,
"end_offset" : 10,
"type" : "gram",
"position" : 107
},
{
"token" : "的_饭",
"start_offset" : 9,
"end_offset" : 11,
"type" : "gram",
"position" : 108
},
{
"token" : "this_is",
"start_offset" : 12,
"end_offset" : 19,
"type" : "gram",
"position" : 209
},
{
"token" : "is_my",
"start_offset" : 17,
"end_offset" : 22,
"type" : "gram",
"position" : 210
},
{
"token" : "my",
"start_offset" : 20,
"end_offset" : 22,
"type" : "<ALPHANUM>",
"position" : 211
},
{
"token" : "food",
"start_offset" : 23,
"end_offset" : 27,
"type" : "<ALPHANUM>",
"position" : 212
}
]
}
# conditional token filter
# 作用 : 条件过滤，以条件判断是否执行过滤器中的内容
# 配置项 :
# 1. filter : 过滤器
# 2. script : 过滤脚本
GET /_analyze
{
"tokenizer": "standard",
"filter": [{
"type" : "condition",
"filter" : ["lowercase"],
"script" : {
"source": "token.getTerm().length() < 5"
}
}],
"text": ["THE QUICK BROWN FOX"]
}
# 结果
{
"tokens" : [
{
"token" : "the",
"start_offset" : 0,
"end_offset" : 3,
"type" : "<ALPHANUM>",
"position" : 0
},
{
"token" : "QUICK",
"start_offset" : 4,
"end_offset" : 9,
"type" : "<ALPHANUM>",
"position" : 1
},
{
"token" : "BROWN",
"start_offset" : 10,
"end_offset" : 15,
"type" : "<ALPHANUM>",
"position" : 2
},
{
"token" : "fox",
"start_offset" : 16,
"end_offset" : 19,
"type" : "<ALPHANUM>",
"position" : 3
}
]
}
# decimal digit token filter
# 作用 : 特殊数字字符转为阿拉伯数字
GET /_analyze
{
"tokenizer": "keyword",
"filter": ["decimal_digit"],
"text": ["6.7 १ १-one two-२ ३ "]
}
# 结果
{
"tokens" : [
{
"token" : "6.7 1 1-one two-2 3 ",
"start_offset" : 0,
"end_offset" : 20,
"type" : "word",
"position" : 0
}
]
}
