ElasticSearch Java API-Retrieving index libraries

The previous blog recorded how to write data to an index using the Java Call API, and how to search this time.

First, prepare the data

    StringData1 = Jsonutil.model2json (NewBlog (1,"Introduction to Git","2016-06-19","The main difference between SVN and git ..."));StringData2 = Jsonutil.model2json (NewBlog (2,"Introduction and simple use of generics in Java","2016-06-19","Learning objectives to master the meaning of generics ..."));StringData3 = Jsonutil.model2json (NewBlog (3,"SQL basic Operations","2016-06-19","Basic operation: CRUD ..."));StringDATA4 = Jsonutil.model2json (NewBlog (4,"Hibernate Framework Basics","2016-06-19","Hibernate framework Basics ..."));StringData5 = Jsonutil.model2json (NewBlog (5,"Git Basics git","2016-06-19","What the shell is ..."));StringDATA6 = Jsonutil.model2json (NewBlog (6,"Basic knowledge of C + +","2016-06-19","What the shell is ..."));StringData7 = Jsonutil.model2json (NewBlog (7,"MySQL Basics","2016-06-19","What Git is ..."));

Second, query

A single query can be divided into the following four steps:

• 1. Create a client that connects to the Elasticsearch service.
  Index on the Elasticsearch server, the first step is to create a connection to the server.

  Client client = TransportClient.builder().build()            .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));

• 2. Create a querybuilder.
  QueryBuilder you can set a query for a single field, or you can set up multiple fields.
  e.g.1: Query hibernate The document containing the keyword in the title field:

  QueryBuilder qb1 = termQuery("title", "hibernate");

  e.g.2: Queries the document that contains the keyword in the title field or the Content field git :

  QueryBuilder qb2= QueryBuilders.multiMatchQuery("git", "title","content");

• 3. Execute the query
  Set the index, type, and query of the queries through the client. Returns a SearchResponse object:

  SearchResponse response = client.prepareSearch("blog").setTypes("article").setQuery(qb2).execute()            .actionGet();

• 4. Working with query Results
  The Gethits () method of the SearchResponse object gets the query results, returns a collection of Searchhits, and iterates through the collection to get the document information for the query:

  SearchHits hits = response.getHits();

Third, Java code implementation

Package CN. com. Bropen. Es;Import Java. NET. InetAddress;Import Java. NET. Unknownhostexception;import org. Elasticsearch. Action. Search. SearchResponse;import org. Elasticsearch. Client. Client;import org. Elasticsearch. Client. Transport. Transportclient;import org. Elasticsearch. Common. Transport. Inetsockettransportaddress;import org. Elasticsearch. Index. Query. Multimatchquerybuilder;import org. Elasticsearch. Index. Query. QueryBuilder;import org. Elasticsearch. Index. Query. Querybuilders;import org. Elasticsearch. Search. Searchhit;import org. Elasticsearch. Search. Searchhits;Import static Org. Elasticsearch. Index. Query. Querybuilders.*;public class Elasticsearchget {public static void main (string[] args) {//client startup try { Client client = Transportclient. Builder(). Build(). Addtransportaddress(New Inetsockettransportaddress (inetaddress. Getbyname("127.0.0.1"),9300));QueryBuilder QB1 = Termquery ("title","Hibernate");QueryBuilder qb2= Querybuilders. Multimatchquery("Git","title","Content");SearchResponse response = Client. Preparesearch("Blog"). Settypes("article"). Setquery(QB2). Execute(). Actionget();Searchhits hits = response. Gethits();if (hits. Totalhits() >0) {for (Searchhit hit:hits) {System. out. println("Score:"+hit. Getscore()+": \ T"+hit. GetSource());//. Get ("title")}} else {System. out. println([0 results found ]);}} catch (Unknownhostexception e) {E. Printstacktrace();}    }}

Query Result:

Log4j:warn No appenders could be found forLogger (org.elasticsearch.plugins). Log4j:warn Initialize the log4j system Properly.log4j:WARN See/HTTP logging.apache.org/log4j/1.2/faq.html#noconfig for more info.Score:0.5: {posttime= .- .- +, id=1, Title=git Introduction, the main difference between CONTENT=SVN and git...}score:0.17673586: {posttime= .- .- +, id=7, Title=mysql basic knowledge, content=git is what...}score:0.049935166: {posttime= .- .- +, id=5, Title=git basic knowledge of git, Content=shell is what...}

Resources:

1. Distributed Search Elasticsearch Java API (v)--Search
2. GET API
3. Elasticsearch Chinese Guide –java-api

ElasticSearch Java API-Retrieving index libraries