标签：col evel new rate utf8 http bsp span dice
xxx_by_query包括_delete_by_query和_update_by_query，下面分开讲
_delete_by_query
相当于sql中的delete from a where 。。。删除满足条件的文档
在Dev Tools执行的格式是
POST teacher/_doc/_delete_by_query
{
"query": {
"range": {
"updated_date": {
"from": 1534007400000,
"to": 1534007700000
}
}
}
}
值得注意的是，Java High Level REST Client截止到6.3.2版本(elasticsearch-rest-high-level-client-6.3.2.jar)，尽管有DeleteByQueryRequest类，可以通过DeleteByQueryRequest(SearchRequest search)构造器构造一个实例，但是RestHighLevelClient实例没有合适的方法来操作DeleteByQueryRequest实例(如RestHighLevelClient实例可以用index(XxxRequest xxxRequest, Header... headers)实例方法来操作索引的文档，可以用indices()实例方法获取IndicesClient实例，进而通过其各种实例方法来操作索引，但是没有方法的入参是DeleteByQueryRequest实例)。
想在java代码中实现delete_by_query功能，有2种替代方法：
1.先用searchRequest筛选出符合条件的文档的id集合，然后根据id用deleteRequest来删除。
2.调用RestHighLevelClient实例的getLowLevelClient()方法获取org.elasticsearch.client.RestClient实例，即low-level client，然后调用其performRequest(String method, String endpoint, Map<String, String> params, HttpEntity entity, Header... headers)方法，其中method是"POST"，endpoint是"/index/doc/_delete_by_query"，代码示例如下：
public static void main(String[] args) throws Exception { RestHighLevelClient client = new RestHighLevelClient( RestClient.builder( new HttpHost("192.168.56.11", 9200, "http"), new HttpHost("192.168.56.12", 9201, "http") ) ); try { HttpEntity entity = new NStringEntity(generateQueryString(), ContentType.APPLICATION_JSON); Response response = client.getLowLevelClient().performRequest("POST", "/teacher/_doc/_delete_by_query", Collections.emptyMap(), entity); Map responseMap = JSON.parseObject(IOUtils.toString(response.getEntity().getContent(), "UTF-8")); LOGGER.info(responseMap); } catch (Exception e) { LOGGER.error("client delete_by_query exception", e); } finally { if (client != null) { client.close(); } } } public static String generateQueryString() { IndexRequest indexRequest = new IndexRequest(); XContentBuilder builder; try { long begin = 1534015700000L; long end = 1534016700000L; builder = JsonXContent.contentBuilder() .startObject() .startObject("query") .startObject("range") .startObject("updated_date").field("from", begin).field("to", end) .endObject() .endObject() .endObject() .endObject(); indexRequest.source(builder); } catch (IOException e) { e.printStackTrace(); } return indexRequest.source().utf8ToString(); }
标签：col evel new rate utf8 http bsp span dice
原文地址：https://www.cnblogs.com/koushr/p/9520811.html
