search-9.3-java.md

endpoint	search
lang	java
es_version	9.3
client	co.elastic.clients:elasticsearch-java:9.3.0

Elasticsearch 9.3 search endpoint (Java example)

Use client.search() to find documents matching a query.

public record Product(String name, String brand, double price,
                      String category,
                      @JsonProperty("in_stock") boolean inStock,
                      double rating) {}

var response = client.search(s -> s
        .index("products")
        .query(q -> q
            .match(m -> m.field("category").query("electronics"))
        )
        .sort(so -> so.field(f -> f.field("price").order(SortOrder.Asc))),
    Product.class
);

System.out.println("Found " + response.hits().total().value() + " products");
for (var hit : response.hits().hits()) {
    var doc = hit.source();
    System.out.println("  " + doc.name() + " — $" + doc.price());
}

Pagination

Use from and size to paginate through results:

int page = 0;
int pageSize = 10;

var response = client.search(s -> s
        .index("products")
        .query(q -> q.matchAll(m -> m))
        .from(page * pageSize)
        .size(pageSize)
        .sort(so -> so.field(f -> f.field("price").order(SortOrder.Desc))),
    Product.class
);

For deep pagination beyond 10,000 results, use searchAfter with a point-in-time instead.

Aggregations

Use aggregations to compute summary statistics alongside search results. Set size(0) when you only need the aggregation:

var response = client.search(s -> s
        .index("products")
        .size(0)
        .aggregations("by_category", a -> a
            .terms(t -> t.field("category.keyword"))
            .aggregations("avg_price", sub -> sub
                .avg(av -> av.field("price"))
            )
        ),
    Void.class
);

for (var bucket : response.aggregations().get("by_category").sterms().buckets().array()) {
    var avg = bucket.aggregations().get("avg_price").avg().value();
    System.out.printf("  %s: %d products, avg $%.2f%n",
        bucket.key().stringValue(), bucket.docCount(), avg);
}