How to create an index in java

How to create an index in java: first convert the object into a JSON string; then write the json document into the index; finally use Java code to create a new Java project and write the index creation code call in it. .

An index is an on-disk structure associated with a table or view that speeds up the retrieval of rows from the table or view. An index contains keys generated from one or more columns in a table or view. In fact, the key purpose of the index is to speed up retrieval. Therefore, how to use the index is a matter of the database system itself. As a database designer or user, you can design and create the index and then experience how the query becomes faster after adding the index. . So, how to create an index in Java?

1. Generate JSON

The first step in creating an index is to convert the object into a JSON string

2 , Create an index

Write the json document into the index

3. Java implements a new Java project

The specific code is as follows:

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 {
            /* 创建客户端 */
            // client startup
            Client 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("创建成功!");
                }
            }
            client.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

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