ElasticSearch 例子

ElasticSearch是一个接近实时的搜索平台，它利用Lucese进行文档索引。

本文会写个可以运行的简单例子，方便大家上手，日后深入了解。

需要引入maven依赖

<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>5.1.1</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>transport</artifactId>
    <version>5.1.1</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.9.0</version>
</dependency>

然后是测试主程序

import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * Created by joe on 2017/9/25.
 */
public class ElasticSearch {
    public static void main(String[] args) {
        TransportClient client;
        Settings esSettings = Settings.builder()
                .put("cluster.name", "elasticsearch") //设置ES实例的名称
                .put("client.transport.sniff", true) //自动嗅探整个集群的状态，把集群中其他ES节点的ip添加到本地的客户端列表中
                .build();
        client = new PreBuiltTransportClient(esSettings);//初始化client较老版本发生了变化，此方法有几个重载方法，初始化插件等。
        //此步骤添加IP，至少一个，其实一个就够了，因为添加了自动嗅探配置
        try {
            client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        Map<String,Object> infoMap = new HashMap<String, Object>();
        infoMap.put("name", "广告信息11");
        infoMap.put("title", "我的广告22");
        infoMap.put("createTime", new Date());
        infoMap.put("count", 1022);
        IndexResponse indexResponse = client.prepareIndex("test", "info","100").setSource(infoMap).
                execute().actionGet();

        QueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("count").gt(50);
        SearchResponse searchResponse = client.prepareSearch("test")
                .setTypes("info")
                .setQuery(rangeQueryBuilder)
                .addSort("count", SortOrder.DESC)
                .setSize(20)
                .execute()
                .actionGet();
        SearchHits hits = searchResponse.getHits();
        System.out.println("查到记录数：" + hits.getTotalHits());
        SearchHit[] searchHists = hits.getHits();
        if(searchHists.length>0){
            for(SearchHit hit:searchHists){
                String name =  (String) hit.getSource().get("name");
                Integer age = (Integer)hit.getSource().get("count");
                String date = (String) hit.getSource().get("createTime");
                System.out.format("name:%s ,count :%d, createTime:%s\n", name, age, date);
            }
        }

    }
}

　　

不要忘了配置 log4j2.properties

appender.console.type = Console
appender.console.name = console
appender.console.layout.type = PatternLayout

rootLogger.level = info
rootLogger.appenderRef.console.ref = console

以上就可以了。

tips: jdk8以下可能会遇到问题。