ElasticSearch Java API-Create an index

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

First, generate JSON

The first step in creating an index is to convert the object to a JSON string. There are four ways to create JSON documents:

1.1 Handwriting Style generation

String json = "{" +        "\"user\":\"kimchy\"," +        "\"postDate\":\"2013-01-30\"," +        "\"message\":\"trying out Elasticsearch\"" +    "}";

Handwriting is simple, but note the date format: Date formate

1.2 Using Collections

A collection is a Key:value data type that can represent a JSON structure.

Map<StringObjectnew HashMap<StringObject>();json.put("user","kimchy");json.put("postDate",newDate());json.put("message","trying out Elasticsearch");

1.3 Use of Jackson serialization

Elasticsearch has used Jackson and can use it directly to convert JavaBean to JSON.

// instance a json mappernew// create once, reuse// generate jsonbyte[] json = mapper.writeValueAsBytes(yourbeaninstance);

1.4 Using the Elasticsearch Help class

import static Org .common  .xcontent  . * Xcontentbuilder builder = Jsonbuilder () .startobject  () .field  (, " Kimchy ") .field         ( "postdate" , New Date ()) .field  ( "message" ,  "trying out Elasticsearch" ) .endobject  () String json = Builder.string  ( )   

Second, create an index

The following example writes a JSON document so the index library is named Twitter, and the type Tweet,id is 1:

Import static Org. Elasticsearch. Common. Xcontent. Xcontentfactory.*;Indexresponse response = Client. Prepareindex("Twitter","tweet","1"). SetSource(Jsonbuilder (). StartObject(). Field("User","Kimchy"). Field("Postdate", new Date ()). Field("Message","trying out Elasticsearch"). EndObject()                  ). Get();

You can also directly descendant a JSON string:

String"{" +        "\"user\":\"kimchy\"," +        "\"postDate\":\"2013-01-30\"," +        "\"message\":\"trying out Elasticsearch\"" +    "}"response = client.prepareIndex("twitter""tweet")        .setSource(json)        .get();

You can call the methods of the response object to get the return information:

// 索引名称String _index = response.getIndex();// 类型名称String _type = response.getType();// 文档idString _id = response.getId();// 版本(if it‘stime1)long _version = response.getVersion();// 是否被创建isifisnewif it has been updatedboolean created = response.isCreated();

It's easier to System.out.println(response) see the return information directly.

Third, Java implementation

Create a new Java project and import the jar file under the Elasticsearch-2.3.3/lib directory. Create a new blog class:

publicclass Blog {    private Integer id;    private String title;    private String posttime;    private String content;    publicBlog() {    }    publicBlog(Integer id, String title, String posttime, String content) {        this.id = id;        this.title = title;        this.posttime = posttime;        this.content = content;    }  //setter and getter  ｝

To create a Java entity class to JSON tool class:

Import Java. IO. IOException;import org. Elasticsearch. Common. Xcontent. Xcontentbuilder;import org. Elasticsearch. Common. Xcontent. Xcontentfactory;public class Jsonutil {//Java Entity object to JSON object public static string Model2json (blog blog) {string jsondata = nul L;try {xcontentbuilder Jsonbuild = xcontentfactory. Jsonbuilder();Jsonbuild. StartObject(). Field("id", blog. GetId()). Field("title", blog. GetTitle()). Field("Posttime", blog. Getposttime()). Field("Content", blog. GetContent()). EndObject();Jsondata = Jsonbuild. String();System. out. println(Jsondata);} catch (IOException e) {E. Printstacktrace();} return Jsondata;}}

Add data to return a list:

ImportJava.Util.ArrayList;ImportJava.Util.Date;ImportJava.Util.List; PublicClass DataFactory { PublicStatic DataFactory DataFactory= NewDataFactory ();PrivateDataFactory () {} PublicDataFactory getinstance () {returnDataFactory; } PublicStaticList<String>Getinitjsondata () {List<String> List = NewArrayList<String>();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,"Shell Basics","2016-06-19","What the shell is ..."));List.Add (data1);List.Add (DATA2);List.Add (DATA3);List.Add (DATA4);List.Add (DATA5);return List; }}

To create an index, add data:

Import Java. IO. IOException;Import Java. NET. InetAddress;Import Java. NET. Unknownhostexception;Import Java. Util. Date;Import Java. Util. List;import org. Elasticsearch. Action. Index. Indexresponse;import org. Elasticsearch. Client. Client;import org. Elasticsearch. Client. Transport. Transportclient;import org. Elasticsearch. Common. Transport. Inetsockettransportaddress;import org. Elasticsearch. Common. Xcontent. Xcontentbuilder;Import CN. com. Bropen. Entity. DataFactory;Import static Org. Elasticsearch. Common. Xcontent. Xcontentfactory.*;public class Elasticsearchhandler {public static void main (string[] args) {try {/ * Create client * /Client Startup Client client = Transportclient. Builder(). Build(). Addtransportaddress(New Inetsockettransportaddress (inetaddress. Getbyname("127.0.0.1"),9300));Xcontentbuilder builder = Jsonbuilder (). StartObject(). Field("User","Kimchy"). Field("Postdate", new Date ()). Field("Message","trying out Elasticsearch"). EndObject();list<string> Jsondata = DataFactory. Getinitjsondata();for (int i =0; i < jsondata.size (); i++) {Indexresponse response = Client. Prepareindex("Blog","article"). SetSource(Jsondata. Get(i)). Get();if (response. iscreated()) {System. out. println("created successfully!");}} Client. Close();} catch (Unknownhostexception e) {E. Printstacktrace();} catch (IOException e) {E. Printstacktrace();}    }}

To view the inserted data:

ElasticSearch Java API-Create an index