Elasticsearch LangField Plugin

Overview

LangField Plugin provides a useful feature for multi-language enrivonment.

Version

Versions in Maven Repository

Issues/Questions

Please file an issue. (Japanese forum is here.)

Installation

For 5.x

$ $ES_HOME/bin/elasticsearch-plugin install org.codelibs:elasticsearch-langfield:5.3.0

For 2.x

$ $ES_HOME/bin/plugin install org.codelibs/elasticsearch-langfield/2.4.1

Getting Started

Create Index for Multi-Languages

First, you need to create index which has fields for multi-languages:

$ curl -XPUT 'localhost:9200/my_index' -d '
{
  "mappings" : {
    "my_type" : {
      "properties" : {
        "message" : {
          "type" : "langstring"
        },
        "message_en" : {
          "type" : "string"
        },
        "message_ja" : {
          "type" : "string"
        }
      }
    }
  },
  "settings" : {
    "index" : {
      "number_of_shards" : "5",
      "number_of_replicas" : "0"
    }
  }
}'

where message_* field is for multi-language. Using message field with "langstring" type, message_* fields are stored automaticaly. The above index-setting JSON is just an example. It's better to specify a proper analyzer for message_* field.

Insert Documents

Insert 2 documents for English and Japanese:

$ curl -XPOST "localhost:9200/my_index/my_type/1" -d '{
  "message":"This is a pen."
}'
$ curl -XPOST "localhost:9200/my_index/my_type/2" -d '{
  "message":"これはペンです。"
}'

message field detects language and then copy the content of message field to a proper message_* field. Check the result with exists filter query:

$ curl -XPOST "http://localhost:9200/my_index/my_type/_search" -d'
{
  "query": {
    "filtered": {
      "query": {
        "match_all": {}
      },
      "filter": {
        "exists": {
          "field": "message_en"
        }
      }
    }
  }
}'
{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 1,
    "hits": [
      {
        "_index": "my_index",
        "_type": "my_type",
        "_id": "1",
        "_score": 1,
        "_source": {
          "message": "This is a pen."
        }
      }
    ]
  }
}

Next, check if message_ja field exists:

$ curl -XPOST "http://localhost:9200/my_index/my_type/_search" -d'
{
  "query": {
    "filtered": {
      "query": {
        "match_all": {}
      },
      "filter": {
        "exists": {
          "field": "message_ja"
        }
      }
    }
  }
}'
{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 1,
    "hits": [
      {
        "_index": "my_index",
        "_type": "my_type",
        "_id": "2",
        "_score": 1,
        "_source": {
          "message": "これはペンです。"
        }
      }
    ]
  }
}