Use of the Elasticsearch 6.0java API

Use of Java APIs in Elasticsearch 6.0

1: Create Elasticsearch client using Java API

 PackageCom.search.elasticsearch;Importorg.elasticsearch.client.transport.TransportClient;Importorg.elasticsearch.common.settings.Settings;Importorg.elasticsearch.common.transport.TransportAddress;Importorg.elasticsearch.transport.client.PreBuiltTransportClient;Importjava.io.IOException;ImportJava.io.InputStream;Importjava.net.InetAddress;Importjava.util.Properties; Public classElasticsearchconfig {Private Statictransportclient Client;  Publictransportclient getelasticsearchclient () {Try{Settings Settings=Settings.builder (). Put ("Cluster.name", "My-eslearn")//the connected cluster name. put ("Client.transport.ignore_cluster_name",true)//if the cluster name is not correct, you can also connect. Build (); //Create clientClient =Newprebuilttransportclient (Settings). addtransportaddress (NewTransportaddress (Inetaddress.getbyname ("127.0.0.1"), 9300));//host and port number            returnclient; } Catch(Exception e) {e.printstacktrace (); }        return NULL; }}

2: Use client to create INDEX, some fields in index specify IK word breaker, etc.

Package Com.search.elasticsearch;

ImportOrg.elasticsearch.action.DocWriteResponse;ImportOrg.elasticsearch.action.admin.indices.analyze.AnalyzeRequestBuilder;Importorg.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;ImportOrg.elasticsearch.action.bulk.BulkItemResponse;ImportOrg.elasticsearch.action.bulk.BulkRequestBuilder;ImportOrg.elasticsearch.action.bulk.BulkResponse;ImportOrg.elasticsearch.action.get.GetResponse;Importorg.elasticsearch.action.index.IndexRequest;ImportOrg.elasticsearch.action.index.IndexResponse;ImportOrg.elasticsearch.action.search.SearchResponse;ImportOrg.elasticsearch.action.search.SearchType;Importorg.elasticsearch.action.update.UpdateRequest;ImportOrg.elasticsearch.action.update.UpdateResponse;Importorg.elasticsearch.client.IndicesAdminClient;Importorg.elasticsearch.client.Requests;Importorg.elasticsearch.client.transport.TransportClient;Importorg.elasticsearch.common.settings.Settings;Importorg.elasticsearch.common.transport.TransportAddress;ImportOrg.elasticsearch.common.xcontent.XContentBuilder;Importorg.elasticsearch.common.xcontent.XContentFactory;Importorg.elasticsearch.index.query.QueryBuilders;Importorg.elasticsearch.transport.client.PreBuiltTransportClient;Importorg.springframework.beans.factory.annotation.Autowired;ImportOrg.springframework.beans.factory.annotation.Value;Importjava.io.IOException;ImportJava.io.InputStream;Importjava.net.InetAddress;Importjava.util.Date;Importjava.util.List;Importjava.util.Properties;ImportJava.util.ResourceBundle;Importjava.util.concurrent.ExecutionException;Import StaticOrg.elasticsearch.common.xcontent.XContentFactory.jsonBuilder; Public classElasticsearchutil {Private Statictransportclient Client;  PublicElasticsearchutil () { This. client=NewElasticsearchconfig (). Getelasticsearchclient ();//Use the above created goodthe client is added to the class.     }    //creates an index and assigns IK participles to certain fields in the index, and then uses IK participles to query the index later.      Public voidCreateIndex ()throwsIOException {//Creating MappingsXcontentbuilder mapping =Xcontentfactory.jsonbuilder (). StartObject (). StartObject ("Properties")                //. StartObject ("m_id"). Field ("type", "keyword"). EndObject ()
Title: Field name, type: Text Type Analyzer: type of Word breaker
. StartObject ("title"). Field ("Type", "Text"). Field ("Analyzer", "Ik_smart"). EndObject ()//The field is added, and the Ik_smart word breaker will be used when querying. StartObject ("Content"). Field ("Type", "Text"). Field ("Analyzer", "Ik_max_word"). EndObject (). EndObject (). EndObject (); //index: Index name Type: type name (you can define it yourself)Putmappingrequest Putmap = requests.putmappingrequest ("index"). Type ("type")). Source (mapping); //Create an indexClient.admin (). Indices (). Preparecreate ("index"). Execute (). Actionget (); //to add a map to an indexclient.admin (). Indices (). putmapping (Putmap). Actionget (); }}

This time the index is created, mapping cannot be dropped.

3: Add content to the index created in step up, including id,id cannot be duplicated

     Public void throws IOException {        = Client.prepareindex ("index", "type", "1")//index, type, id                . SetSource (Jsonbuilder ()                        . StartObject ()                        . Field ("title", "title")   //field, Value                        . field ("content", "content" ).                        endobject ()                ). get ();    }

Use postman to query the index:

4: Update index, update the index just created, if the same ID will overwrite the content just now

     Public void throws IOException, Executionexception, interruptedexception {        // each time the add ID should be different, equivalent to the primary key in the data table, the same The words will be overwritten        updateresponse response = client.update ( "index", "type", "1")                . doc (Xcontentfactory.jsonbuilder ()                        . StartObject ()                        field ("title", "National anthem of the People's Republic of China, the national anthem is the most beautiful song" )                        . Field ("content", "the national anthem of the People's Republic of China, the national anthem is the most pleasant song"). EndObject ())                ). get ();    

Use postman to view the contents of the index

5: Query the index, because the word breaker is different, the word breaker will be queried for the content of the first word, and then in the sub-paragraph query.

Query sub-section content

Query Result:

To query the title sub-segment:

Query Result:

6: Add another piece of data to the index

     Public void throws IOException {        = Client.prepareindex ("index", "type", "2")                . SetSource (Jsonbuilder ()                        . StartObject ()                        . Field("title", "The Chinese nation is a great nation").                        field ("content", "The Chinese nation is a great nation")                        . EndObject ()                ). get ();    }

To query the content of a field:

Results: Two data can be found, because the query content, "the national anthem of the People's Republic of China" for fine-grained division, containing the word "Chinese", two of the data contain "China".

To query the field title:

Query result: Only one piece of data, because coarse-grained participle is used for title

7:search API Operation:

public void Search () {
SearchResponse response1 = Client.preparesearch ("index1", "index")//Specify Multiple indexes
. Settypes ("Type1", "type")//Specify Type
. Setsearchtype (Searchtype.query_then_fetch)
. Setquery (Querybuilders.matchquery ("title", "National anthem of the People's Republic of China")//Query
. Setpostfilter (Querybuilders.rangequery ("age"). from (a) to ()//Filter
. Setfrom (0). SetSize. Setexplain (True)
. get ();
Long totalhits1= response1.gethits (). totalhits; Number of Hits
System.out.println (TOTALHITS1);
        
SearchResponse Response2 = Client.preparesearch ("index1", "index")//Specify Multiple indexes
. Settypes ("Type1", "type")//Specify Type
. Setsearchtype (Searchtype.query_then_fetch)
. Setquery (Querybuilders.matchquery ("Content", "national anthem of the People's Republic of China"))//Query
. Setpostfilter (Querybuilders.rangequery ("age"). from (a) to ()//Filter
. Setfrom (0). SetSize. Setexplain (True)
. get ();
Long totalHits2 = Response2.gethits (). totalhits; Number of Hits
System.out.println (TOTALHITS2);
}

8:get API Operation:

     Public void get () {        = client.prepareget ("index", "type", "1"). get ();        Map<string, object> Source = Response.getsource ();        Set<String> strings = source.keyset ();        Iterator<String> Iterator = strings.iterator ();          while (Iterator.hasnext ()) {            System.out.println (Source.get (Iterator.next ()));        }    }

Java API Official document: Https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.0/java-docs-index.html

Use of the Elasticsearch 6.0java API