Java下Elasticsearh应用指南

简介

　　本文针对在Java下操作elasticsearch给出应用示例，主要涉及创建连接，构建索引以及检索数据3个部分。

环境

　　1）elasticsearch2.4.4，

　　2）jdk1.8。

客户端连接

import java.net.InetAddress;
import java.net.UnknownHostException;

import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class Client {
    private static Logger logger = LoggerFactory.getLogger(Client.class);
    private static Settings settings = Settings.settingsBuilder()
　　　　　　　　　　　　.put("cluster.name", "app").build();

    /**
     * only one address
     * @param ipAddress
     * @return
     */
    public static TransportClient initClient(String ipAddress) {
        TransportClient client = null;
        try {
            client = TransportClient.builder().settings(settings).build()
                    .addTransportAddress(new InetSocketTransportAddress(
　　　　　　　　　　　　InetAddress.getByName(ipAddress), 9300));
            logger.info("client start up", ipAddress);
        } catch (UnknownHostException e) {
            e.printStackTrace();
            logger.error(ipAddress, e.getMessage());
        }
        
        return client;
    }
    
    
    /**
     * has more addresses
     * @param ipAddress
     * @return
     */
    public static TransportClient initClient(String[] ipAddress) {
        TransportClient client = null;
        try {
            client = TransportClient.builder().settings(settings).build();
            for (String ip : ipAddress) {
                client.addTransportAddress(new InetSocketTransportAddress(
　　　　　　　　　　InetAddress.getByName(ip), 9300));
            }
        } catch (UnknownHostException e) {
            logger.error(ipAddress.toString(), e.getMessage());
        }
        
        return client;
    }
    
    
    public static void close(TransportClient client) {
        if (client != null) {
            client.close();
        }
    }

}

创建索引

import java.util.Map;

import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.admin.indices.exists.indices.IndicesExistsRequest;
import org.elasticsearch.action.admin.indices.exists.indices.IndicesExistsResponse;
import org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Index {
    private static Logger logger = LoggerFactory.getLogger(Index.class);
    
    /**
     * create index before mapping
     * @param client
     * @param indexName
     */
    public static void indexCreate(TransportClient client, String indexName) {
        deleteIndex(client, indexName);
        client.admin().indices()
        .create(new CreateIndexRequest(indexName))
        .actionGet();
    }
    

    /**
     * set the mapping for index
     * @param client
     * @param indexName
     * @param docName
     * @return
     */
    public static PutMappingResponse indexMapping(TransportClient client, String indexName, 
　　　　　　　　String docName) {
        indexCreate(client, indexName);
        PutMappingResponse response = client.admin().indices()
                .preparePutMapping(indexName)
                .setType(docName)
                .setSource(getMapping(docName))
                .execute()
                .actionGet();
        
        return response;
    }
    
    
    /**
     * index for target data
     * @param client
     * @param indexName
     * @param docName
     * @param data
     * @return
     */
    public static IndexResponse createIndexResponse(TransportClient client, 
            String indexName, String docName, Map<String, String> data) {
        IndexResponse response = client.prepareIndex(indexName, docName)
                .setSource(data)
                .execute()
                .actionGet();
        
        return response;
    }
    
    
    public static void deleteIndex(TransportClient client, String indexName) {
        IndicesExistsResponse isExistsResponse = client.admin().indices()
                .exists(new IndicesExistsRequest(indexName))
                .actionGet();
        if (isExistsResponse.isExists()) {
            client.admin().indices()
            .delete(new DeleteIndexRequest(indexName))
            .actionGet();
        }
    }

}

检索索引

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.lucene.index.Fields;
import org.apache.lucene.index.PostingsEnum;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchType;
import org.elasticsearch.action.termvectors.TermVectorsResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Search {
    private static Logger logger = LoggerFactory.getLogger(Search.class);
    
    /**
     * get the search response with the index and document for keyword
     * @param client
     * @param indexName
     * @param docName
     * @param field
     * @param keyword
     * @return
     */
    public static SearchResponse getSearchResponse(TransportClient client, 
　　　　　　　　String indexName, String docName, String field, String keyword) {
        SearchResponse response = client.prepareSearch(indexName)
                .setTypes(docName)
                .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
                .setQuery(QueryBuilders.matchQuery(field, keyword))
                .setFrom(0).setSize(60).setExplain(true)
                .execute()
                .actionGet();
            
        return response;
    }
    
    
    /**
     * get the terms vector for the target field
     * @param client
     * @param indexName
     * @param docName
     * @param docID
     * @return
     */
    public static TermVectorsResponse getTermVectorResponse(TransportClient client, 
　　　　　　　　String indexName, String docName, String docID, String field) {
        TermVectorsResponse response = client
                .prepareTermVectors(indexName, docName, docID)
                .setSelectedFields(field)
                .setPositions(true)
                .setOffsets(true)
                .execute().actionGet();
        return response;
    }
    
    
    /**
     * get the match String for target field
     * @param response
     * @param field
     * @return
     */
    public static Map<String, String> getMatchField(SearchResponse response, 
　　　　　　　　　　String field) {
        long total = 0;
        Map<String, String> map = null;
        if (response != null) {
            SearchHits hits = response.getHits();
            if (hits != null) {
                total = hits.getTotalHits();
                if (total > 0) {
                    map = new HashMap<String, String>();
                    SearchHit[] searchHits = hits.getHits();
                    for (SearchHit hit : searchHits) {
                        String value = (String)hit.getSource().get(field);
                        String id = hit.getId();
                        map.put(id, value);
                    }
                }
            }
        }
        
        return map;
    }
}

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　　作者：志青云集
　　出处：http://www.cnblogs.com/lyssym
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