WonRay/dsl-query-builder

A DSL query builder that can be used with Jest and has no depandancies other that google gson

DSL Query Builder

Deprecation

Note : This project is no more in development.

A Java REST client had been officially released since, and should be prefered. See https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/index.html

Why this project ?

I was using Jest for one of my project, as I had to query Elastic Search in Java. But as an other part of the programm I was working on was using an outdated Lucene version, I couldn't use Lucene's query builder.

To solve this problem, I decided to write my own query builder, with only a depandancy to Google Json library.

How does it work ?

Using it is very simple... First have a look to queries and filters to know what kind of query you can perform with Elastic Search. Names used in this project are very similar, so finding the stuff you need should not be too complicated.

You have two basic objects :

• a DSLQuery that represents a query you can perform with elastic search. Each query that can be built with this project implements this interface. The basic operation you can perform with DSLQueries is to get them as JSON.
• You have the same thing with DSLFilter.
• You can combine a query and filter using the DSLQueryBuilder. This object is here to make the creation of a query easier : if you have only a filter, the JSON generated will be a filtered match all query, if it is a query with no filter it will return the JSON of your query, and if you decide to combine a query with a filter, it will create a filtered query.

Install

1. Clone this project
2. Run 'maven clean package install'
3. Add this as a maven dependency :

    <dependency>
      <groupId>tellier.es.dsl.query.builder</groupId>
      <artifactId>dsl-query-builder</artifactId>
      <version>1.0-SNAPSHOT</version>
    </dependency>

Examples

Using Jest

Using the DSL query builder with Jest is very simple. If you have initialized a Jest Client, you just have to do :

JestClient jestClient;
String searchQueryString = new DSLBuilder()
                .setQuery(new DSLMatchAllQuery())
                .setFilter(new DSLTermFilter("user").stringFilter("kimchi"))
                .build()
                .toString();
Search search = new Search.Builder(searchQueryString)
                .addIndex("twitter")
                .addType("tweet")
                .build();
SearchResult searchResult = jestClient.execute();

This will perform the following operation :

curl -XPOST 'http://your.elastic.search.cluster/twitter/tweet/_search' -d '
{
	"query" : {
    	"filtered" : {
        	"query" : {
            	"match_all" : {}
            },
            "filter" : {
            	"term" : {"user" : "kimchi"}
            }
        }
    }
}'

Other items

Here comes a non exhaustive list of what you can do with the DSL Query Builder.

• DSLMatchAllQuery

System.out.println(new DSLMatchAllQuery().getQueryAsJson());

Would give :

{
	"match_all" : {}
}

• DSLMatchQuery

System.out.println(new DSLMatchQuery("user", "kimchi").getQueryAsJson());

Would give :

{
	"match" : {"user":"kimchi"}
}

• DSLBoolQuery

System.out.println(new DSLBoolQuery()
						.must(new DSLMatchQuery("user", "kimchi"))
                        .must(new DSLMatchQuery("article", "travel"))
                        .should(new DSLMatchQuery("location", "Paris"))
                        .should(new DSLMatchQuery("location", "London"))
                        .must_not(new DSLMatchQuery("media", "Television"))
						.getQueryAsJson()
);

Would give :

{
	"bool" : {
    	"must" : [
        	{
            	"match" : {"user":"kimchi"}
            },
            {
            	"match" : {"article":"travel"}
            }
        ],
        "should" : [
        	{
            	"match" : {"location":"Paris"}
            },
            {
            	"match" : {"location":"London"}
            }
        ],
        "must_not" : [
        	{
            	"match" : {"media":"Television"}
            }
        ]
    }
}

• DSLRangeFilter

System.out.println(new DSLRangeFilter("date").gte("2014/05/12"));

would give :

{
	"range" : {
    	"date" : {
        	"gte" : "2014/05/12"
        }
    }
}

and :

System.out.println(new DSLRangeFilter("date").gte(2048));

would give :

{
	"range" : {
    	"date" : {
        	"gte" : 2048
        }
    }
}

More generically, it provides almost every queries and filters listed here.

What to come ?

I still need to extend the number of filters I am supporting. I think I will have a first release in the coming days.

I think I will also add a Mapping Builder ( I was compelled to do it by hand ) and Index Builder ( idem ).

License

It is developed under the Licensed under the Apache License, Version 2.0 (the "License") :

you may not use this work except in compliance with the License. You may obtain a copy of the License in the LICENSE file, or at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Contribute

You feel I missed something ? You want to support new DSL features ?

Well, just fork me, and submit pull requests.

You need to :

• provide tests for what you implemented
• links to official ElasticSearch documentations for feature you implemented