elasticsearch之java api

1、初始化一个 RestHighLevelClien

  RestHighLevelClient client = new RestHighLevelClient(
 RestClient.builder(
 new HttpHost("localhost", 9200, "http"),
 new HttpHost(\"localhost\", 9201, \"http\")));

这里可以一次创建多个es的连接

2、查询

（1）get api

 //创建查询请求
  GetRequest getRequest = new GetRequest(_index,_type,_id);
 //发起请求
 GetResponse getResponse = client.get(getRequest);
 //请求结果,是否存在，存在就获取
 if(getResponse.isExists()){
     getResponse.getSourceAsString();
 }

（2）search api

 //创建SearchSourceBuilder，设置请求体参数
 SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
 //设置分页
 if(offset !=null && limit != null){
 sourceBuilder.from(offset);
 sourceBuilder.size(limit);
 }
 //设置多条件
 BoolQueryBuilder queryBuilder = QueryBuilders.boolQuery();
 //这是and连接查询
 queryBuilder.must(QueryBuilders.matchPhraseQuery("name","bd"));
 queryBuilder .must(QueryBuilders.matchPhraseQuery("age","19"));
 //范围查询，jdk8语法：LocalDateTime
 queryBuilder .must(QueryBuilders.rangeQuery("createtime").from(LocalDateTime.parse (startDate, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"))).includeLower(true));
 queryBuilder .must(QueryBuilders.rangeQuery("createtime").to(LocalDateTime.parse (endDate, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"))).includeUpper(true));
 sourceBuilder.query(queryBuilder);
 //设置查询超时时间
 sourceBuilder.timeout(new TimeValue(30, TimeUnit.SECONDS));
 //创建请求
 //设置_index
 SearchRequest searchRequest = new SearchRequest(index);
 //设置_type
 if(!StringUtils.isEmpty(type)){
 searchRequest.types(type);
 }
 //设置请求体参数
 searchRequest.source(sourceBuilder);
 //发送请求
 SearchResponse searchResponse = client.search(searchRequest);\
 SearchHits hits = searchResponse.getHits();
 //获取总记录数
 int totalHits = (int)hits.getTotalHits();
 //获取内容
 hit.getSourceAsString();