ElasticSearch的JAVA API

末蓝、 2022-02-13 08:47 176阅读 0赞

ES对Java提供一套操作索引库的工具包，即Java API。所有的ES操作都使用Client对象执行。

# (一)导入依赖 #

<dependencies>
            
            <dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>transport</artifactId>
                <version>5.2.2</version>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-api</artifactId>
                <version>2.7</version>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-core</artifactId>
                <version>2.7</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>RELEASE</version>
            </dependency>
        </dependencies>

# (二)测试代码 #

package cn.itsource.es;
    
    
    import org.apache.lucene.queryparser.xml.builders.BooleanQueryBuilder;
    import org.elasticsearch.action.bulk.BulkRequestBuilder;
    import org.elasticsearch.action.bulk.BulkResponse;
    import org.elasticsearch.action.delete.DeleteResponse;
    import org.elasticsearch.action.get.GetResponse;
    import org.elasticsearch.action.index.IndexRequestBuilder;
    import org.elasticsearch.action.index.IndexResponse;
    import org.elasticsearch.action.search.SearchResponse;
    import org.elasticsearch.action.update.UpdateResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.transport.InetSocketTransportAddress;
    import org.elasticsearch.index.query.BoolQueryBuilder;
    import org.elasticsearch.index.query.QueryBuilder;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.search.SearchHit;
    import org.elasticsearch.search.sort.SortOrder;
    import org.elasticsearch.transport.client.PreBuiltTransportClient;
    import org.junit.Test;
    
    import java.net.InetAddress;
    import java.net.UnknownHostException;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    public class TestEs {
    
        //拿到操作es的对象
    
        /**
         * TransportClient  利用transport模块远程连接一个ES集群。
         * 它并不加入到集群中，只是简单的获得一个或者多个初始化的transport地址，并以轮询的方式与这些地址进行通信。
         */
        public static TransportClient getClient() throws Exception {
            TransportClient client = new PreBuiltTransportClient(Settings.EMPTY).
                    addTransportAddress(new InetSocketTransportAddress(
                            InetAddress.getByName("localhost"),9300));
            return client;
        }
    
        //创建一条记录
        @Test
        public void createEsIndex() throws Exception {
            TransportClient client = getClient();
            //创建索引库，
            IndexRequestBuilder indexRequestBuilder = client.prepareIndex("crm", "user", "1");
            Map mp = new HashMap();
            mp.put("id",111);
            mp.put("name","木村拓哉");
            mp.put("age",22);
    
            mp.put("id",222);
            mp.put("name","工藤静香");
            mp.put("age",20);
            IndexResponse indexResponse = indexRequestBuilder.setSource(mp).get();
    
            //返回的indexResponse对象可以获取到_index,_type,_version,_id等元数据
            System.out.println(indexResponse);
        }
    
        //获取文档内的数据
        @Test
        public void testGetSource() throws Exception{
            TransportClient client = getClient();
    
            //从索引库内取值，
            GetResponse response = client.prepareGet("crm", "user", "1").get();
            //获取source部分数据
            System.out.println(response.getSource());
        }
    
        //修改文档内的数据
        @Test
        public void testUpdateSource() throws Exception{
            TransportClient client = getClient();
            Map mp = new HashMap();
            mp.put("id",333);
            mp.put("name","木村希美");
            mp.put("age",18);
            //取到值
            UpdateResponse updateResponse = client.prepareUpdate("crm", "user", "1").setDoc(mp).get();
            GetResponse response = client.prepareGet("crm", "user", "1").get();
            //获取source部分数据
            System.out.println(response.getSource());
        }
    
        //删除es的文档对象
        @Test
        public void testDeleteSource() throws Exception{
            TransportClient client = getClient();
    
            //取到值
            DeleteResponse deleteResponse = client.prepareDelete("crm", "user", "1").get();
            //获取source部分数据
            System.out.println(deleteResponse);
        }
    
        //批量插入
        @Test
        public void testBulk() throws Exception{
    
            TransportClient client = getClient();
            BulkRequestBuilder bulkRequestBuilder = client.prepareBulk();
            for(int i=0;i<=10;i++){
                Map mp = new HashMap();
                mp.put("id",i);
                mp.put("name","木村"+i);
                mp.put("age",18+i);
                mp.put("class",1);
                //批量插入
                bulkRequestBuilder.add(client.prepareIndex("crm","classes",i+"").setSource(mp));
            }
    
            BulkResponse bulkItemResponses = bulkRequestBuilder.get();
            if(bulkItemResponses.hasFailures()){
                System.out.println("error");
            }
            client.close();
    
        }
    
        //搜索 1班的人  过滤 age 20-25  分页 0, 3   sort id desc
        @Test
        public void testDSLQuery() throws Exception{
            TransportClient client = getClient();
            //BooleanQueryBuilder
            BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
            //条件：1班
            List<QueryBuilder> must = boolQueryBuilder.must();
            must.add(QueryBuilders.termQuery("class",1));
    
            //过滤条件 20<= age <=25
            List<QueryBuilder> filter = boolQueryBuilder.filter();
            filter.add(QueryBuilders.rangeQuery("age").gte(20).lte(25));
    
            //分页显示 从第0个开始, 每页显示3个，以id的降序排列
            SearchResponse searchResponse = client.prepareSearch("crm")
                    .setFrom(0).setSize(3).setQuery(boolQueryBuilder)
                    .addSort("id", SortOrder.DESC).get();
    
            System.out.println("总的命中数:"+searchResponse.getHits().getTotalHits());
    
            SearchHit[] hits = searchResponse.getHits().getHits();
            for (SearchHit hit : hits) {
                System.out.println(hit.getSource());
            }
            client.close();
        }
    }