Java 相当于 elasticsearch CURL 查询？

Question

My project had a new reqiurement of migrating all datas which are currently in postresql to elasticsearch. Successfully migrated all my datas, but I am stuck with writing java code to search for some datas in elastic search index.

Sample structure of a hit in index is attached in the below image:

I need to find average of activity.attentionLevel from the index.

I wrote something like below query to find average:

GET proktor-activities/_search
{
"aggs" : {
    "avg_attention" : { 
        "avg" : { 
            "script" : "Float.parseFloat(doc['activity.attentionLevel.keyword'].value)" }
         }
    }
}

please help me to find java equivalent code for doing the same.

thanks in advance

Answer 1

Using Elastic's RestHighLevel API would be something like this:

    // Create the client
    RestHighLevelClient client = new RestHighLevelClient(
            RestClient.builder(new HttpHost("localhost", 9200, "http")));

    // Specify the aggregation request
    SearchRequest searchRequest = new SearchRequest("proktor-activities");
    SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
    searchSourceBuilder.aggregation(AggregationBuilders
        .avg("avg_attention")
        .field("activity.attentionLevel"));

    searchRequest.source(searchSourceBuilder);

    // Execute the aggreagation with Elasticsearch
    SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);

    // Read the aggregation result
    Aggregations aggregations = response.getAggregations();
    Avg averageAttention = aggregations.get("avg_attention");
    double result = averageAttention.getValue();

    client.close(); // get done with the client

More information here .