Elasticsearch之ik中文分词篇

ik分词器插件

es在7.3版本已经支持中文分词，由于中文分词只能支持到单个字进行分词，不够灵活与适配我们平常使用习惯，所以有很多对应中文分词出现，最近使用的是ik分词器，就说说它吧。

ik分词器安装

安装可以百度下有很多教程，需要注意的是ik分词器的版本要跟es版本对应上，避免出现不必要的兼容问题。

ik分词模式

ik_max_word: 将文本拆分成最细粒度的词语或者字

GET /test_analysis/_analyze
{
  "text": "是否分词",
  "analyzer": "ik_max_word"
}

结果

{
  "tokens" : [
    {
      "token" : "是否",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "是",
      "start_offset" : 0,
      "end_offset" : 1,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "否",
      "start_offset" : 1,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "分词",
      "start_offset" : 2,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 3
    },
    {
      "token" : "分",
      "start_offset" : 2,
      "end_offset" : 3,
      "type" : "CN_WORD",
      "position" : 4
    },
    {
      "token" : "词",
      "start_offset" : 3,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 5
    }
  ]
}

ik_smart: 将文本拆分成最粗粒的词语

GET /test_analysis/_analyze
{
  "text": "是否分词",
  "analyzer": "ik_smart"
}

结果

{
  "tokens" : [
    {
      "token" : "是否",
      "start_offset" : 0,
      "end_offset" : 2,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "分词",
      "start_offset" : 2,
      "end_offset" : 4,
      "type" : "CN_WORD",
      "position" : 1
    }
  ]
}

一般都用ik_max_word

es ik分词测试

创建索引

PUT /test_analysis
{
  "mappings": {
    "properties": {
      "message": {
        "type": "text",
        "analyzer": "ik_max_word"
      },
      "id": {
        "type": "keyword"
      }
    }
  }
}

添加数据

POST /test_analysis/_bulk
{"index":{}}
{"id":"111", "message":"我是一个小可爱"}
{"index":{}}
{"id":"222", "message":"只是为了测试一下结果是否分词"}
{"index":{}}
{"id":"333", "message":"测试一下是否进行了ik分词"}
{"index":{}}
{"id":"444", "message":"搞一些假的数据吧"}
{"index":{}}
{"id":"555", "message":"实在不知道再写一些什么了"}
{"index":{}}
{"id":"666", "message":"就这样吧"}

查询

GET /test_analysis/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "match": {
            "message": "是否分词"
          }
        }
      ]
    }
  }
}

查询分词结果

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 3,
      "relation" : "eq"
    },
    "max_score" : 5.104265,
    "hits" : [
      {
        "_index" : "test_analysis",
        "_type" : "_doc",
        "_id" : "MDXEe4wBS_Neyb68FBdy",
        "_score" : 5.104265,
        "_source" : {
          "id" : "333",
          "message" : "测试一下是否进行了ik分词"
        }
      },
      {
        "_index" : "test_analysis",
        "_type" : "_doc",
        "_id" : "LzXEe4wBS_Neyb68FBdy",
        "_score" : 5.0611815,
        "_source" : {
          "id" : "222",
          "message" : "只是为了测试一下结果是否分词"
        }
      },
      {
        "_index" : "test_analysis",
        "_type" : "_doc",
        "_id" : "LjXEe4wBS_Neyb68FBdy",
        "_score" : 0.728194,
        "_source" : {
          "id" : "111",
          "message" : "我是一个小可爱"
        }
      }
    ]
  }
}