roschlau / eskotlin

Elasticsearch Query DSL for Kotlin

ES Kotlin

Elasticsearch Query DSL for Kotlin.

This library aims to minimize the gap between the Elasticsearch JSON query DSL, and the API used when writing kotlin applications. This integrates with the existing java API, only providing a nicer syntax to build the queries.

Getting Started

Gradle

repositories {
    mavenCentral()
    ...
    maven {
        url  "http://dl.bintray.com/mbuhot/maven"
   }
}
dependencies {
    compile 'mbuhot:eskotlin:0.4.0'
    ...
}

See CHANGELOG for older versions supporting previous elasticsearch client versions.

Maven

Full details on bintray

<dependency>
  <groupId>mbuhot</groupId>
  <artifactId>eskotlin</artifactId>
  <version>0.4.0</version>
  <type>pom</type>
</dependency>

Examples

Term Query

JSON:

{
    "term" : { "user" : "Kimchy" }
}

Kotlin:

val query = term {
    "user" to "Kimchy"
}

Bool Query

JSON:

{
    "bool" : {
        "must" : {
            "term" : { "user" : "kimchy" }
        },
        "filter": {
            "term" : { "tag" : "tech" }
        },
        "must_not" : {
            "range" : {
                "age" : { "from" : 10, "to" : 20 }
            }
        },
        "should" : [
            {
                "term" : { "tag" : "wow" }
            },
            {
                "term" : { "tag" : "elasticsearch" }
            }
        ],
        "minimum_should_match" : 1,
        "boost" : 1.0
    }
}

Kotlin:

val query = bool {
    must {
        term { "user" to "kimchy" }
    }
    filter {
        term { "tag" to "tech" }
    }
    must_not {
        range {
            "age" {
                from = 10
                to = 20
            }
        }
    }
    should = listOf(
        term { "tag" to "wow" },
        term { "tag" to "elasticsearch" })
    minimum_should_match = 1
    boost = 1.0f
}

Function Score Query

JSON:

{
    "function_score": {
        "query": {
            "match_all": {}
        },
        "functions": [
            {
                "filter": {
                    "term": {
                        "foo": "bar"
                    }
                },
                "gauss": {
                    "baz": {
                        "scale": 1.0
                    }
                }
            },
            {
                "filter": {
                    "match_all": {}
                },
                "random_score": {
                    "seed": 234
                }
            },
            {
                "exp": {
                    "qux": {
                        "scale": 2.3
                    }
                }
            }
        ],
        "score_mode": "max",
        "boost_mode": "multiply",
        "max_boost": 5.0,
        "boost": 1.2,
        "min_score": 0.001
    }
}

Kotlin:

val query = function_score {
    query = match_all { }
    functions = listOf(
        term { "foo" to "bar" } to gaussDecayFunction("baz", 1.0),
        match_all { } to randomFunction(234L),
        null to exponentialDecayFunction("qux", 2.3))

    boost = 1.2f
    boost_mode = "multiply"
    score_mode = "max"
    max_boost = 5.0f
    min_score = 0.001f
}

See the src/test directory for more examples.

API Coverage

Full Text Queries - Done

• Match
• Multi Match
• Common Terms

Term Queries - Done

• Term
• Terms
• Range
• Exists
• Prefix
• Wildcard
• Regex
• Fuzzy
• Type
• Ids

Compound Queries - Done

• Constant Score
• Bool
• Dis Max
• Function Score
• Boosting
• Indices

Joining Queries - Done

• Nested
• Has Child
• Has Parent

Geo Queries - Not Yet Implemented

• Geo Shape
• Geo Bounding Box
• Geo Distance Range
• Geo Polygon
• Geohash Cell

Specialized Queries - Not Yet Implemented

• More Like This
• Template
• Script

Span Queries - Not Yet Implemented

• Span Term
• Span Multi Term
• Span First
• Span Near
• Span Or
• Span Not
• Span Containing
• Span Within

License

MIT - See LICENSE file for full text.