ElasticSearch Java API官網文檔：https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/java-docs-index.html

一、生成JSON

---

創建索引的第一步是要把對象轉換為JSON字符串.官網給出了四種創建JSON文檔的方法：

1.1手寫方式生成

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

手寫方式很簡單，但是要注意日期格式：Date Formate

1.2使用集合

集合是key:value數據類型，可以代表json結構.

Map<String, Object> json = new HashMap<String, Object>(); json.put("user","kimchy"); json.put("postDate",new Date()); json.put("message","trying out Elasticsearch");

1.3使用JACKSON序列化

ElasticSearch已經使用了jackson，可以直接使用它把javabean轉為json.

// instance a json mapper ObjectMapper mapper = new ObjectMapper(); // create once, reuse// generate json byte[] json = mapper.writeValueAsBytes(yourbeaninstance);

1.4使用ElasticSearch 幫助類

import static org.elasticsearch.common.xcontent.XContentFactory.*;XContentBuilder builder = jsonBuilder().startObject().field("user", "kimchy").field("postDate", new Date()).field("message", "trying out Elasticsearch").endObject()String json = builder.string();

二、創建索引

---

下面的例子把json文檔寫入所以，索引庫名為twitter、類型為tweet,id為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();

也可以直接傳人JSON字符串：

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

更簡單的可以直接System.out.println(response)查看返回信息.

三、java實現

---

新建一個Java項目，導入elasticsearch-2.3.3/lib目錄下的jar文件.新建一個Blog類：

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

創建java實體類轉json工具類：

import java.io.IOException;import org.elasticsearch.common.xcontent.XContentBuilder; import org.elasticsearch.common.xcontent.XContentFactory;public class JsonUtil {// Java實體對象轉json對象public static String model2Json(Blog blog) {String jsonData = null;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;}}

添加數據，返回一個list：

import java.util.ArrayList; import java.util.Date; import java.util.List;public class DataFactory {public static DataFactory dataFactory = new DataFactory();private DataFactory() {}public DataFactory getInstance() {return dataFactory;}public static List<String> getInitJsonData() {List<String> list = new ArrayList<String>();String data1 = JsonUtil.model2Json(new Blog(1, "git簡介", "2016-06-19", "SVN與Git最主要的區別..."));String data2 = JsonUtil.model2Json(new Blog(2, "Java中泛型的介紹與簡單使用", "2016-06-19", "學習目標 掌握泛型的產生意義..."));String data3 = JsonUtil.model2Json(new Blog(3, "SQL基本操作", "2016-06-19", "基本操作：CRUD ..."));String data4 = JsonUtil.model2Json(new Blog(4, "Hibernate框架基礎", "2016-06-19", "Hibernate框架基礎..."));String data5 = JsonUtil.model2Json(new Blog(5, "Shell基本知識", "2016-06-19", "Shell是什么..."));list.add(data1);list.add(data2);list.add(data3);list.add(data4);list.add(data5);return list;}}

創建索引、添加數據：

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 {/* 創建客戶端 */// client startupClient client = TransportClient.builder().build().addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));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("創建成功!");}}client.close();} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}

• 40

查看插入的數據：

總結

以上是生活随笔為你收集整理的ElasticSearch Java Api(一) －创建索引的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。