使用JAVA操作ElasticSearch(JAVA API)

我的ElasticSearch集群的版本是6.2.4,导入elasticsearch相关的maven依赖也是6.2.4,不同版本的api可能会有差异

一:maven依赖

   <!--elasticsearch核心依赖-->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>6.2.4</version>
        </dependency>
        <!--elasticsearch客户端-->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>6.2.4</version>
        </dependency>
        <!--日志-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-to-slf4j</artifactId>
            <version>2.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.24</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.21</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <!--单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>compile</scope>
        </dependency>
        <!--实体转json-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.10.2</version>
        </dependency>

        <!--实体类简化工具-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.18</version>
        </dependency>

2.单元测试的共有方法

  TransportClient client;

    @Before
    //创建连接
    public void connection() throws UnknownHostException {
        //创建客户端连接对象
        //参数为configelasticsearch.yml中对应的值 也就是集群名称
        Settings settings = Settings.builder().put("cluster.name", "elasticsearch").build();
        client = new PreBuiltTransportClient(settings);
        client.addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.118.3"), 9300));
        client.addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.118.4"), 9300));
        client.addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.118.5"), 9300));
    }



  @After
    //释放资源
    public void close() {
        client.close();
    }



    //遍历结果集
    public void iteratorSearchHit(SearchHits searchHits) {
        System.out.println("符合查询条件有:" + searchHits.getTotalHits() + "条");
        //获取迭代器
        Iterator<SearchHit> iterator = searchHits.iterator();
        System.out.println("开始进行遍历------------------------------");
        while (iterator.hasNext()) {
            //获取每个查询对象
            SearchHit searchHit = iterator.next();
            //获取字符串类型并进行打印
            System.out.println(searchHit.getSourceAsString());
            Map<String, Object> sourceAsMap = searchHit.getSourceAsMap();
            System.out.println("符合搜索条件的标题是:=======" + sourceAsMap.get("title"));
            /*   for (Map.Entry<String,Object> map:sourceAsMap.entrySet()){
                System.out.println("===================================");
                System.out.println(map.getKey());
                System.out.println(map.getValue());
            }
            */
        }
    }

3.常规操作

   @Test
    //创建索引库
    public void createIndex() {
        //索引名成必须小写
        client.admin().indices().prepareCreate("myindex1").get();
    }

    @Test
    //添加映射
    public void mapping() throws IOException, ExecutionException, InterruptedException {
        XContentBuilder builder = XContentFactory.jsonBuilder().startObject()
                .startObject("type1")
                .startObject("properties")
                .startObject("id")
                .field("type", "integer")
                .field("store", "true")
                .endObject()
                .startObject("title")
                .field("type", "text")
                .field("store", "true")
                .field("analyzer", "ik_smart")
                .endObject()
                .startObject("content")
                .field("type", "text")
                .field("store", "true")
                .field("analyzer", "ik_smart")
                .endObject()
                .endObject()
                .endObject()
                .endObject();
        PutMappingRequest mappingRequest = Requests.putMappingRequest("myindex1")
                .type("type1")
                .source(builder);
        client.admin().indices().putMapping(mappingRequest).get();
    }

    @Test
    //给myindex1的type1创建文档
    public void createDocument() throws IOException {
        XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
        xContentBuilder.startObject()
                .field("id", 1)
                .field("title", "ElasticSearch是一个基于Lucene的搜索服务器")
                .field("content", "它提供了一个分布式多用户能力的全文搜索引擎，基于RESTful web接口。Elasticsearch是用 Java开发的，并作为Apache许可条款下的开放源码发布，是当前流行的企业级搜索引擎。设计用于云计算中，能够达到 实时搜索，稳定，可靠，快速，安装使用方便。")
                .endObject();
        //参数1:索引名 2:类型 3:id
        client.prepareIndex("myindex1", "type1", "1").setSource(xContentBuilder).get();

    }

    @Test
    //通过实体转json创建文档
    public void jsonDocument() throws JsonProcessingException {
        Type1 type1 = new Type1();
        type1.setId(2);
        type1.setTitle("通过实体转json创建文档");
        type1.setContent("通过创建实体的方式,将实体转json");
        ObjectMapper objectMapper = new ObjectMapper();
        client.prepareIndex("myindex1", "type1", type1.getId().toString())
                .setSource(objectMapper.writeValueAsString(type1).getBytes(), XContentType.JSON)
                .get();
    }

    @Test
    //关键词查询
    public void termQuery() {
        //设置搜索条件,目标索引库,目标类型,目标域
        SearchResponse searchResponse = client.prepareSearch("myindex1")
                .setTypes("type1")
                .setQuery(QueryBuilders.termQuery("content", "实体")).get();
        SearchHits hits = searchResponse.getHits();
        iteratorSearchHit(hits);
    }

    @Test
    //字符串查询
    public void stringQuery() {
        //设置搜索条件,目标索引库,目标类型
        SearchResponse searchResponse = client.prepareSearch("myindex1")
                .setTypes("type1")
                .setQuery(QueryBuilders.queryStringQuery("搜索实体")).get();
        SearchHits hits = searchResponse.getHits();
        iteratorSearchHit(hits);
    }

    @Test
    //根据文档ID进行查询
    public void idQuery() {
        SearchResponse searchResponse = client.prepareSearch("myindex1")
                .setQuery(QueryBuilders.idsQuery("type1").addIds("2"))
                .get();
        iteratorSearchHit(searchResponse.getHits());
    }

    //分页之前的操作,批量添加文档
    @Test
    public void batchInsert() throws JsonProcessingException {
        Type1 type1;
        for (int i = 1; i <= 50; i++) {
            type1 = new Type1();
            type1.setId(i);
            type1.setTitle(i + "通过实体转json创建文档");
            type1.setContent(i + "通过创建实体的方式,将实体转json");
            ObjectMapper objectMapper = new ObjectMapper();
            client.prepareIndex("myindex1", "type1", type1.getId().toString())
                    .setSource(objectMapper.writeValueAsString(type1).getBytes(), XContentType.JSON)
                    .get();
        }
    }

    //搜索文档并分页显示
    @Test
    public void pageDocument() {
        SearchResponse searchResponse = client.prepareSearch("myindex1")
                .setTypes("type1")
                .setQuery(QueryBuilders.matchAllQuery())
                //setFrom()：从第几条开始检索，默认是0。
                // setSize():每页最多显示的记录数默认是十
                .setFrom(0)
                .setSize(5)
                .get();
        iteratorSearchHit(searchResponse.getHits());
    }


    //模拟搜索结果高亮显示
    @Test
    public void highlight() {
        //设置查询条件
        SearchRequestBuilder searchRequestBuilder = client.prepareSearch("myindex1")
                .setTypes("type1")
                .setQuery(QueryBuilders.termQuery("title", "实体"));
        //高亮设置
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        //开头的标签信息
        highlightBuilder.preTags("<font style='color:red'>");
        //结尾的标签
        highlightBuilder.postTags("</font>");
        highlightBuilder.field("title");
        searchRequestBuilder.highlighter(highlightBuilder);
        SearchResponse searchResponse = searchRequestBuilder.get();
        Iterator<SearchHit> iterator = searchResponse.getHits().iterator();
        while (iterator.hasNext()) {
            SearchHit hit = iterator.next();
            System.out.print("正常String方式打印文档搜索内容====");
            System.out.println(hit.getSourceAsString());
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            //遍历集合,输出高亮数据
            //方式1
            Text[] titles = highlightFields.get("title").getFragments();
            for (Text str : titles) {
                System.out.println(str);
            }
        }
    }