ElasticSearch实战系列三: ElasticSearch的JAVA API使用教程

时间 2019-11-21

标签 elasticsearch 实战系列 java api 使用教程栏目日志分析繁體版

原文原文链接

前言

在上一篇中介绍了ElasticSearch实战系列二: ElasticSearch的DSL语句使用教程---图文详解，本篇文章就来说解下 ElasticSearch 6.x官方Java API的使用。html

ElasticSearch JAVA API

目前市面上有几种常见的ElasticSearch Java API架包，JestClient、SpringBoot整合的SpringData、Spring整合的ElasticsearchTemplate、Elasticsearch Bboss等一些开源架包，上述这些第三方整合的架包中，基本已经支持平常的使用，除了支持的ES版本会低一些而已。java

本文介绍的是ElasticSearch官方的Java High Level REST Client的使用，Java High Level REST Client是ElasticSearch官方目前推荐使用的，适用于6.x以上的版本，要求JDK在1.8以上，能够很好的在大版本中进行兼容，而且该架包自身也包含Java Low Level REST Client中的方法，能够应对一些特需的状况进行特殊的处理，它对于一些经常使用的方法封装Restful风格，能够直接对应操做名调用使用便可，支持同步和异步(Async)调用。git

这里咱们的使用也能够直接对应上一篇文章中的DSL语句使用，这样的话能够很是方便的对照和学习使用。github

在对下述进行操做时，咱们先来看下Elasticsearch Java High Level REST Client的初始化链接写法吧。json

RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost(elasticIp, elasticPort)));

是否是很简单呢，关闭也很简单，client不为空直接close便可！api

1、新增数据

ElasticSearch能够直接新增数据，只要你指定了index(索引库名称)和type(类型)便可。在新增的时候你能够本身指定主键ID，也能够不指定，由 ElasticSearch自身生成。Elasticsearch Java High Level REST Client新增数据提供了三种方法，这里咱们就来看一下这三种写法吧。缓存

新增数据代码示例一，经过jsonString进行建立：app

String index = "test1";
    String type = "_doc";
    // 惟一编号
    String id = "1";
    IndexRequest request = new IndexRequest(index, type, id);

    String jsonString = "{" + "\"uid\":\"1234\","+ "\"phone\":\"12345678909\","+ "\"msgcode\":\"1\"," + "\"sendtime\":\"2019-03-14 01:57:04\","
            + "\"message\":\"xuwujing study Elasticsearch\"" + "}";
    request.source(jsonString, XContentType.JSON);
    IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);

新增数据代码示例二，经过map建立,会自动转换成json的数据:异步

String index = "test1";
    String type = "_doc";
    // 惟一编号
    String id = "1";
    IndexRequest request = new IndexRequest(index, type, id);
    Map<String, Object> jsonMap = new HashMap<>();
    jsonMap.put("uid", 1234);
    jsonMap.put("phone", 12345678909L);
    jsonMap.put("msgcode", 1);
    jsonMap.put("sendtime", "2019-03-14 01:57:04");
    jsonMap.put("message", "xuwujing study Elasticsearch");
    request.source(jsonMap);
    IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);

新增数据代码示例三，经过XContentBuilder对象进行建立:elasticsearch

String index = "test1";
    String type = "_doc";
    // 惟一编号
    String id = "1";
    IndexRequest request = new IndexRequest(index, type, id);
    XContentBuilder builder = XContentFactory.jsonBuilder();
    builder.startObject();
    {
        builder.field("uid", 1234);
        builder.field("phone", 12345678909L);
        builder.field("msgcode", 1);
        builder.timeField("sendtime", "2019-03-14 01:57:04");
        builder.field("message", "xuwujing study Elasticsearch");
    }
    builder.endObject();
    request.source(builder);
    IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);

上述三种方法中，我的推荐第二种，比较容易理解和使用。

2、建立索引库

在上述示例中，咱们经过直接经过建立数据从而建立了索引库，可是没有建立索引库而经过ES自身生成的这种并不友好，由于它会使用默认的配置，字段结构都是text(text的数据会分词，在存储的时候也会额外的占用空间)，分片和索引副本采用默认值，默认是5和1，ES的分片数在建立以后就不能修改，除非reindex，因此这里咱们仍是指定数据模板进行建立。
使用JAVA API 建立索引库的方法和上述中新增数据的同样，有三种方式，不过这里就只介绍一种。

新增索引库的代码示例:

private static void createIndex() throws IOException {
    String type = "_doc";
    String index = "test1";
    // setting 的值
    Map<String, Object> setmapping = new HashMap<>();
    // 分区数、副本数、缓存刷新时间
    setmapping.put("number_of_shards", 10);
    setmapping.put("number_of_replicas", 1);
    setmapping.put("refresh_interval", "5s");
    Map<String, Object> keyword = new HashMap<>();
    //设置类型
    keyword.put("type", "keyword");
    Map<String, Object> lon = new HashMap<>();
    //设置类型
    lon.put("type", "long");
    Map<String, Object> date = new HashMap<>();
    //设置类型
    date.put("type", "date");
    date.put("format", "yyyy-MM-dd HH:mm:ss");

    Map<String, Object> jsonMap2 = new HashMap<>();
    Map<String, Object> properties = new HashMap<>();
    //设置字段message信息
    properties.put("uid", lon);
    properties.put("phone", lon);
    properties.put("msgcode", lon);
    properties.put("message", keyword);
    properties.put("sendtime", date);
    Map<String, Object> mapping = new HashMap<>();
    mapping.put("properties", properties);
    jsonMap2.put(type, mapping);

    GetIndexRequest getRequest = new GetIndexRequest();
    getRequest.indices(index);
    getRequest.local(false);
    getRequest.humanReadable(true);
    boolean exists2 = client.indices().exists(getRequest, RequestOptions.DEFAULT);
    //若是存在就不建立了
    if(exists2) {
        System.out.println(index+"索引库已经存在!");
        return;
    }
    // 开始建立库
    CreateIndexRequest request = new CreateIndexRequest(index);
    try {
        // 加载数据类型
        request.settings(setmapping);
        //设置mapping参数
        request.mapping(type, jsonMap2);
        //设置别名
        request.alias(new Alias("pancm_alias"));
        CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);
        boolean falg = createIndexResponse.isAcknowledged();
        if(falg){
            System.out.println("建立索引库:"+index+"成功！" );
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

}

注：建立索引库的时候，必定要先判断索引库是否存在！！！
这里建立索引库的时候顺便也指定了别名（alias），这个别名是一个好东西，使用恰当能够提高查询性能，这里咱们留着下次在讲。

3、修改数据

ES提供修改API的时候，有两种方式，一种是直接修改，可是若数据不存在会抛出异常，另外一种则是存在更新，不存着就插入。相比第一种，第二种会更加好用一些，不过在写入速度上是不如第一种的。

ES修改的代码示例:

private static void update() throws IOException {
    String type = "_doc";
    String index = "test1";
    // 惟一编号
    String id = "1";
    UpdateRequest upateRequest = new UpdateRequest();
    upateRequest.id(id);
    upateRequest.index(index);
    upateRequest.type(type);

    // 依旧可使用Map这种集合做为更新条件
    Map<String, Object> jsonMap = new HashMap<>();
    jsonMap.put("uid", 12345);
    jsonMap.put("phone", 123456789019L);
    jsonMap.put("msgcode", 2);
    jsonMap.put("sendtime", "2019-03-14 01:57:04");
    jsonMap.put("message", "xuwujing study Elasticsearch");
    upateRequest.doc(jsonMap);
    // upsert 方法表示若是数据不存在，那么就新增一条
    upateRequest.docAsUpsert(true);
    client.update(upateRequest, RequestOptions.DEFAULT);
    System.out.println("更新成功！");

}

注:upsert 方法表示若是数据不存在，那么就新增一条，默认是false。

4、删除数据

根据上述的几个操做，想必不用多说，已经知道了是DELETE方法了，那咱们就直接开始吧。

ES根据ID删除代码示例:

private static void delete() throws IOException {

    String type = "_doc";
    String index = "test1";
    // 惟一编号
    String id = "1";
    DeleteRequest deleteRequest = new DeleteRequest();
    deleteRequest.id(id);
    deleteRequest.index(index);
    deleteRequest.type(type);
    // 设置超时时间
    deleteRequest.timeout(TimeValue.timeValueMinutes(2));
    // 设置刷新策略"wait_for"
    // 保持此请求打开，直到刷新使此请求的内容能够搜索为止。此刷新策略与高索引和搜索吞吐量兼容，但它会致使请求等待响应，直到发生刷新
    deleteRequest.setRefreshPolicy(WriteRequest.RefreshPolicy.WAIT_UNTIL);
    // 同步删除
    DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
}

ES根据条件进行删除：

private static void deleteByQuery() throws IOException {
    String type = "_doc";
    String index = "test1";
    DeleteByQueryRequest request = new DeleteByQueryRequest(index,type);
    // 设置查询条件
    request.setQuery(QueryBuilders.termsQuery("uid",1234));
    // 同步执行
    BulkByScrollResponse bulkResponse = client.deleteByQuery(request, RequestOptions.DEFAULT);
}

测试结果

示例图:

查询语句

几个经常使用的查询API这里就简单的介绍下用法，而后再直接给出全部的查询语句代码。

查询API

等值（term查询：QueryBuilders.termQuery(name,value);
多值(terms)查询:QueryBuilders.termsQuery(name,value,value2,value3...);
范围（range)查询：QueryBuilders.rangeQuery(name).gte(value).lte(value);
存在(exists)查询:QueryBuilders.existsQuery(name);
模糊(wildcard)查询:QueryBuilders.wildcardQuery(name,+value+);
组合（bool）查询: BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();

查询全部代码示例

private static void allSearch() throws IOException {
    SearchRequest searchRequestAll = new SearchRequest();
    SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
    searchSourceBuilder.query(QueryBuilders.matchAllQuery());
    searchRequestAll.source(searchSourceBuilder);
    // 同步查询
    SearchResponse searchResponseAll = client.search(searchRequestAll, RequestOptions.DEFAULT);
    System.out.println("全部查询总数:" + searchResponseAll.getHits().getTotalHits());
}

通常查询代码示例

其实就是等值查询，只不过在里面加入了分页、排序、超时、路由等等设置，而且在查询结果里面增长了一些处理。

private static void genSearch() throws IOException {
    String type = "_doc";
    String index = "test1";
    // 查询指定的索引库
    SearchRequest searchRequest = new SearchRequest(index);
    searchRequest.types(type);
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    // 设置查询条件
    sourceBuilder.query(QueryBuilders.termQuery("uid", "1234"));
    // 设置起止和结束
    sourceBuilder.from(0);
    sourceBuilder.size(5);
    sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
    // 设置路由
//      searchRequest.routing("routing");
    // 设置索引库表达式
    searchRequest.indicesOptions(IndicesOptions.lenientExpandOpen());
    // 查询选择本地分片，默认是集群分片
    searchRequest.preference("_local");

    // 排序
    // 根据默认值进行降序排序
//  sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));
    // 根据字段进行升序排序
//  sourceBuilder.sort(new FieldSortBuilder("id").order(SortOrder.ASC));

    // 关闭suorce查询
//  sourceBuilder.fetchSource(false);

    String[] includeFields = new String[]{"title", "user", "innerObject.*"};
    String[] excludeFields = new String[]{"_type"};
    // 包含或排除字段
//  sourceBuilder.fetchSource(includeFields, excludeFields);

    searchRequest.source(sourceBuilder);
    System.out.println("普通查询的DSL语句:"+sourceBuilder.toString());
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

    // HTTP状态代码、执行时间或请求是否提早终止或超时
    RestStatus status = searchResponse.status();
    TimeValue took = searchResponse.getTook();
    Boolean terminatedEarly = searchResponse.isTerminatedEarly();
    boolean timedOut = searchResponse.isTimedOut();

    // 供关于受搜索影响的切分总数的统计信息，以及成功和失败的切分
    int totalShards = searchResponse.getTotalShards();
    int successfulShards = searchResponse.getSuccessfulShards();
    int failedShards = searchResponse.getFailedShards();
    // 失败的缘由
    for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
        // failures should be handled here
    }
    // 结果
    searchResponse.getHits().forEach(hit -> {
        Map<String, Object> map = hit.getSourceAsMap();
        System.out.println("普通查询的结果:" + map);
    });
    System.out.println("\n=================\n");
}

或查询

其实这个或查询也是bool查询中的一种，这里的查询语句至关于SQL语句中的

SELECT * FROM test1 where (uid = 1 or uid =2) and phone = 12345678919

代码示例:

private static void orSearch() throws IOException {
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("test1");
    searchRequest.types("_doc");
    SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
    BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();
    BoolQueryBuilder boolQueryBuilder2 = new BoolQueryBuilder();
 
      /**
     *  SELECT * FROM test1 where (uid = 1234 or uid =12345)  and phone = 12345678909
     * */
    boolQueryBuilder2.should(QueryBuilders.termQuery("uid", 1234));
    boolQueryBuilder2.should(QueryBuilders.termQuery("uid", 12345));
    boolQueryBuilder.must(boolQueryBuilder2);
    boolQueryBuilder.must(QueryBuilders.termQuery("phone", "12345678909"));
    searchSourceBuilder.query(boolQueryBuilder);
    System.out.println("或查询语句:" + searchSourceBuilder.toString());
    searchRequest.source(searchSourceBuilder);
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

    searchResponse.getHits().forEach(documentFields -> {

        System.out.println("查询结果:" + documentFields.getSourceAsMap());
    });

}

模糊查询

至关于SQL语句中的like查询。

private static void likeSearch() throws IOException {
    String type = "_doc";
    String index = "test1";
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices(index);
    searchRequest.types(type);
    SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
    BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();

   /**
     *  SELECT * FROM p_test where  message like '%xu%';
     * */
    boolQueryBuilder.must(QueryBuilders.wildcardQuery("message", "*xu*"));
    searchSourceBuilder.query(boolQueryBuilder);
    System.out.println("模糊查询语句:" + searchSourceBuilder.toString());
    searchRequest.source(searchSourceBuilder);
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    searchResponse.getHits().forEach(documentFields -> {
        System.out.println("模糊查询结果:" + documentFields.getSourceAsMap());
    });
    System.out.println("\n=================\n");
}

多值查询

也就是至关于SQL语句中的in查询。

private static void inSearch() throws IOException {
        String type = "_doc";
        String index = "test1";
        // 查询指定的索引库
        SearchRequest searchRequest = new SearchRequest(index,type);
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        /**
         *  SELECT * FROM p_test where uid in (1,2)
         * */
        // 设置查询条件
        sourceBuilder.query(QueryBuilders.termsQuery("uid", 1, 2));
        searchRequest.source(sourceBuilder);
        System.out.println("in查询的DSL语句:"+sourceBuilder.toString());
        // 同步查询
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        // 结果
        searchResponse.getHits().forEach(hit -> {
            Map<String, Object> map = hit.getSourceAsMap();
            String string = hit.getSourceAsString();
            System.out.println("in查询的Map结果:" + map);
            System.out.println("in查询的String结果:" + string);
        });

        System.out.println("\n=================\n");
    }

存在查询

判断是否存在该字段，用法和SQL语句中的exist相似。

private static void existSearch() throws IOException {
    String type = "_doc";
    String index = "test1";
    // 查询指定的索引库
    SearchRequest searchRequest = new SearchRequest(index);
    searchRequest.types(type);
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();

    // 设置查询条件
     sourceBuilder.query(QueryBuilders.existsQuery("msgcode"));
    searchRequest.source(sourceBuilder);
    System.out.println("存在查询的DSL语句:"+sourceBuilder.toString());
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    // 结果
    searchResponse.getHits().forEach(hit -> {
        Map<String, Object> map = hit.getSourceAsMap();
        String string = hit.getSourceAsString();
        System.out.println("存在查询的Map结果:" + map);
        System.out.println("存在查询的String结果:" + string);
    });
    System.out.println("\n=================\n");
}

范围查询

和SQL语句中<>使用方法同样,其中gt是大于，lt是小于，gte是大于等于，lte是小于等于。

private static void rangeSearch() throws IOException{
    String type = "_doc";
    String index = "test1";
    SearchRequest searchRequest = new SearchRequest(index);
    searchRequest.types(type);
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();

    // 设置查询条件
    sourceBuilder.query(QueryBuilders.rangeQuery("sendtime").gte("2019-01-01 00:00:00").lte("2019-12-31 23:59:59"));
    searchRequest.source(sourceBuilder);
     System.out.println("范围查询的DSL语句:"+sourceBuilder.toString());
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    // 结果
    searchResponse.getHits().forEach(hit -> {
        String string = hit.getSourceAsString();
        System.out.println("范围查询的String结果:" + string);
    });
    System.out.println("\n=================\n");
}

正则查询

ES可使用正则进行查询，查询方式也很是的简单，代码示例以下：

private static void regexpSearch() throws IOException{
    String type = "_doc";
    String index = "test1";
    // 查询指定的索引库
    SearchRequest searchRequest = new SearchRequest(index);
    searchRequest.types(type);
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    // 设置查询条件
    sourceBuilder.query(QueryBuilders.regexpQuery("message","xu[0-9]"));
    searchRequest.source(sourceBuilder);
     System.out.println("正则查询的DSL语句:"+sourceBuilder.toString());
    // 同步查询
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    // 结果
    searchResponse.getHits().forEach(hit -> {
        Map<String, Object> map = hit.getSourceAsMap();
        String string = hit.getSourceAsString();
        System.out.println("正则查询的Map结果:" + map);
        System.out.println("正则查询的String结果:" + string);
    });

    System.out.println("\n=================\n");
}

查询测试结果

全部查询总数:6
普通查询的DSL语句:{"from":0,"size":5,"timeout":"60s","query":{"term":{"uid":{"value":"1234","boost":1.0}}}}

=================

或查询语句:{"query":{"bool":{"must":[{"bool":{"should":[{"term":{"uid":{"value":1234,"boost":1.0}}},{"term":{"uid":{"value":12345,"boost":1.0}}}],"adjust_pure_negative":true,"boost":1.0}},{"term":{"phone":{"value":"12345678909","boost":1.0}}}],"adjust_pure_negative":true,"boost":1.0}}}
或查询结果:{msgcode=1, uid=12345, phone=12345678909, message=qq, sendtime=2019-03-14 01:57:04}

=================

模糊查询语句:{"query":{"bool":{"must":[{"wildcard":{"message":{"wildcard":"xu","boost":1.0}}}],"adjust_pure_negative":true,"boost":1.0}}}
模糊查询结果:{msgcode=2, uid=12345, phone=123456789019, sendtime=2019-03-14 01:57:04, message=xuwujing study Elasticsearch}
模糊查询结果:{uid=123456, phone=12345678909, message=xu1, sendtime=2019-03-14 01:57:04}

=================

存在查询的DSL语句:{"query":{"exists":{"field":"msgcode","boost":1.0}}}
存在查询的Map结果:{msgcode=2, uid=12345, phone=123456789019, sendtime=2019-03-14 01:57:04, message=xuwujing study Elasticsearch}
存在查询的String结果:{"uid":12345,"phone":123456789019,"msgcode":2,"sendtime":"2019-03-14 01:57:04","message":"xuwujing study Elasticsearch"}
存在查询的Map结果:{msgcode=1, uid=12345, phone=12345678909, message=qq, sendtime=2019-03-14 01:57:04}
存在查询的String结果:{"uid":"12345","phone":"12345678909","message":"qq","msgcode":"1","sendtime":"2019-03-14 01:57:04"}

=================

范围查询的DSL语句:{"query":{"range":{"sendtime":{"from":"2019-01-01 00:00:00","to":"2019-12-31 23:59:59","include_lower":true,"include_upper":true,"boost":1.0}}}}
范围查询的String结果:{"uid":12345,"phone":123456789019,"msgcode":2,"sendtime":"2019-03-14 01:57:04","message":"xuwujing study Elasticsearch"}
范围查询的String结果:{"uid":"123456","phone":"12345678909","message":"xu1","sendtime":"2019-03-14 01:57:04"}
范围查询的String结果:{"uid":"12345","phone":"12345678909","message":"qq","msgcode":"1","sendtime":"2019-03-14 01:57:04"}

=================

正则查询的DSL语句:{"query":{"regexp":{"message":{"value":"xu[0-9]","flags_value":65535,"max_determinized_states":10000,"boost":1.0}}}}
正则查询的Map结果:{uid=123456, phone=12345678909, message=xu1, sendtime=2019-03-14 01:57:04}
正则查询的String结果:{"uid":"123456","phone":"12345678909","message":"xu1","sendtime":"2019-03-14 01:57:04"}

=================

组合查询的DSL语句:{"query":{"bool":{"must":[{"term":{"uid":{"value":12345,"boost":1.0}}},{"term":{"msgcode":{"value":1,"boost":1.0}}}],"adjust_pure_negative":true,"boost":1.0}}}
组合查询的String结果:{"uid":"12345","phone":"12345678909","message":"qq","msgcode":"1","sendtime":"2019-03-14 01:57:04"}

=================

其它

参考ES官方文档：
https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high.html

关于SpringBoot集成ElasticSearch和JestClient的使用能够查看这篇文章：SpringBoot整合ElasticSearch实现多版本的兼容

关于ElasticSearch Java API的选择，若是ElasticSearch版本在6.x之前的话，推荐使用JestClient。若是是6.x以后而且有意升级到7.x的话，那么直接使用ES官方的Java High Level REST Client，由于在7.x以后将直接会舍弃Transport client的链接方式，目前Spring和SpringBoot集成的ES就是使用该方式(不知后续是否会作调整)。

本篇文章的代码已收录在本人的java-study项目中，如有兴趣，欢迎star、fork和issues。
项目地址:https://github.com/xuwujing/java-study

ElasticSearch实战系列:
ElasticSearch实战系列一: ElasticSearch集群+Kinaba安装教程
 ElasticSearch实战系列二: ElasticSearch的DSL语句使用教程---图文详解

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