elasticsearch-java

elastissearch的JAVA客户端

官网 java api文档 https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/client.html

    <dependency>

        <groupId>org.elasticsearch</groupId>

        <artifactId>elasticsearch</artifactId>

    </dependency>

目前有4种：

TransportClient、JestClient、RestClient（一种网络请求，非集群中的一员）

NodeClient（集群中一员，但不存储数据，可以查看集群的状况）

这几个都需要引入对应的Client,同时要引入Netty，因为是基于netty进行网络通信。以TransportClient为例:

    <dependency>

            <groupId>org.elasticsearch.client</groupId>

            <artifactId>transport</artifactId>

        <version>6.2.</version>

    </dependency>
<dependency>
　　<groupId>io.netty</groupId>
　　<artifactId>netty-buffer</artifactId>
　　<version>4.1.28.Final</version>
</dependency>

TransportClient 连接方式有3种，具体参见以下官网连接的例子

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/transport-client.html

代码测试连接：

    @RequestMapping("/connTest")

    public String connectEs() {

        String result = "failure";

        Settings settings = Settings.builder()

                                    .put("cluster.name", "es_test")
                                    .put("client.transport.ping_timeout", "3s")                     //default 5s

                                    .put("client.transport.sniff", true)    //嗅探会自动发现集成的其它ip，只需要设置一个master就可以通过嗅味带出其它的

                                    .build();

        TransportClient client = new PreBuiltTransportClient(settings);

        try {

            client.addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.201.105"), ));

            List<DiscoveryNode> nodeList = client.connectedNodes();

            if(nodeList != null && nodeList.size() > ) {

                result = "success";

            }

            client.close();

        } catch (UnknownHostException e) {

            System.out.println(e);

            result = "failure";

        }

        return result;

    }

一般client被设置为单例模式。

查询：

prepareGet

GET

        GetRequestBuilder reqBuilder = transportClient.prepareGet("ik_test", "type1", "kI1COGUB9PG2P1x3QBda");

        Map<String, Object> mapResult = reqBuilder.get().getSource()

UPDATE

        XContentBuilder source = XContentFactory.jsonBuilder()

                .startObject()

                .field("name", "8月金融数据政策寒冬")

                .field("title", "中国人民银行报道")

                .field("content", "社会融资坏账率明显增多")

                .endObject();

        UpdateResponse updateResp = transportClient.prepareUpdate("ik_test", "type1", "kI1COGUB9PG2P1x3QBda").setDoc(source).get();

        Result result = updateResp.getResult();

IndexRequest ：source

注意 setSource(object...) 是传入的 key,value,key,value,key,value.....

        // key value ...

        transportClient.prepareIndex("ik_test", "type1").setSource("title","BBC报道","name", "the blue planet", "content", "蓝色星球讲述海洋天空大地，以及人类环境对整个地球的影响").get();

        // json

        IkTestVO vo2 = new IkTestVO("VOA报道", "it's a channel to learn english", "一家做voa报道学习英文用");

        transportClient.prepareIndex("ik_test", "type1").setSource(mapper.writeValueAsString(vo2), XContentType.JSON).get();

        //map

        Map<String, Object> vo3 = new HashMap<String, Object>();

        vo3.put("title", "美国之音");

        vo3.put("name", "美国之音广播电台");

        vo3.put("content", "讲述美国文化生活");

        transportClient.prepareIndex("ik_test", "type1").setSource(vo3).get();

        //XcontentBuilder

        XContentBuilder vo4 = XContentFactory.jsonBuilder()

                .startObject()

                .field("name", "9月金融数据政策寒冬")

                .field("title", "中国证监会")

                .field("content", "对于明星涉嫌非法股票套取交易的处罚规定")

                .endObject();

        transportClient.prepareIndex("ik_test", "type1").setSource(vo4).get();

DELETE

transportClient.prepareDelete().setIndex("ik_test").setId("DTbzVWUBIcwRDuO5OPIA").setType("type1").get();

BULK

        BulkRequestBuilder reqBuilder = transportClient.prepareBulk();

        // IndexRequest

        IndexRequest indexReq = new IndexRequest("ik_test","type1");

        IkTestVO vo = new IkTestVO("ABC报道", "the blue planet", "蓝色星球讲述海洋天空大地，以及人类环境对整个地球的影响");

        indexReq.source(mapper.writeValueAsString(vo), XContentType.JSON);

        // DeleteRequest

        DeleteRequest delReq = new DeleteRequest("ik_test","type1","DTbzVWUBIcwRDuO5OPIA");

        // UpdateRequest

        UpdateRequest updReq = new UpdateRequest("ik_test","type1", "DzYJVmUBIcwRDuO5U_If");

        Map<String, Object> vo3 = new HashMap<String, Object>();

        vo3.put("title", "美国之音2");

        vo3.put("name", "美国之音广播电台2");

        vo3.put("content", "讲述美国文化生活2");

        updReq.doc(vo3);

        reqBuilder.add(indexReq);

        reqBuilder.add(delReq);

        reqBuilder.add(updReq);

        BulkResponse bulkResp = reqBuilder.get();

prepareSearch

    @Test

    public void testSearch() {

        SearchResponse search = transportClient.prepareSearch("ik_test")

                                    .setQuery(QueryBuilders.matchQuery("title", "美国"))

                                    .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)

                                    .setFrom()

                                    .setSize()

                                    .get();

        SearchHits  hits = search.getHits();

        long count = hits.getTotalHits();

        System.out.println("count: " + count);

        if(count > ) {

            for(SearchHit hit : hits) {

                System.out.println(hit.getSourceAsString());

            }

        }

    }

结果：

count:

{"name":"美国之音广播电台2","title":"美国之音2","content":"讲述美国文化生活2"}

SearchType:

es的四种查询类型SearchType：

QUERY_AND_FETCH （由主节点分发查询，然后再汇总查询。仅查一次，数据量和排序问题）@deprecated
QUERY_THEN_FETCH（主节点分发查询，汇总分查询的id，然后再查询数据，查两次。同样牵扯数据量和排序）默认形式DEFAULT
DFS_QUERY_THEN_FETCH （解决排序和数据量，但是运行效率差）

QueryBuilders:

　　参看类文件说明