Add Support for Hybrid Query Type

CHANGELOG.md

@@ -37,6 +37,7 @@ This section is for maintaining a changelog for all breaking changes for the cli
 
 ### Added
 - Add search role type for nodes in cluster stats ([#848](https://github.com/opensearch-project/opensearch-java/pull/848))
+- Add support for Hybrid query type ([#850](https://github.com/opensearch-project/opensearch-java/pull/850))
 
 ### Dependencies
 

guides/search.md

@@ -81,6 +81,25 @@ for (int i = 0; i < searchResponse.hits().hits().size(); i++) {
 }
 ```
 
+### Search documents using a hybrid query
+```java
+Query searchQuery = Query.of(
+        h -> h.hybrid(
+                q -> q.queries(Arrays.asList(
+                                       new MatchQuery.Builder().field("text").query(FieldValue.of("Text for document 2")).build().toQuery(),
+                                       new TermQuery.Builder().field("passage_text").value(FieldValue.of("Foo bar")).build().toQuery(),
+                                       new NeuralQuery.Builder().field("passage_embedding").queryText("Hi world").modelId("bQ1J8ooBpBj3wT4HVUsb").k(100).build().toQuery()
+                               )
+                              )
+                )
+        );
+SearchRequest searchRequest = new SearchRequest.Builder().query(searchQuery).build();
+SearchResponse<IndexData> searchResponse = client.search(searchRequest, IndexData.class);
+for (var hit : searchResponse.hits().hits()) {
+        LOGGER.info("Found {} with score {}", hit.source(), hit.score());
+}
+```
+
 ### Search documents using suggesters
 
 [AppData](../samples/src/main/java/org/opensearch/client/samples/util/AppData.java) refers to the sample data class used in the below samples.

java-client/src/main/java/org/opensearch/client/opensearch/_types/query_dsl/HybridQuery.java

@@ -0,0 +1,107 @@
+package org.opensearch.client.opensearch._types.query_dsl;
+
+import jakarta.json.stream.JsonGenerator;
+import java.util.List;
+import java.util.function.Function;
+import org.opensearch.client.json.JsonpDeserializer;
+import org.opensearch.client.json.JsonpMapper;
+import org.opensearch.client.json.ObjectBuilderDeserializer;
+import org.opensearch.client.json.ObjectDeserializer;
+import org.opensearch.client.util.ApiTypeHelper;
+import org.opensearch.client.util.ObjectBuilder;
+
+public class HybridQuery extends QueryBase implements QueryVariant {
+    private final List<Query> queries;
+
+    private HybridQuery(HybridQuery.Builder builder) {
+        super(builder);
+        this.queries = ApiTypeHelper.unmodifiable(builder.queries);
+    }
+
+    public static HybridQuery of(Function<HybridQuery.Builder, ObjectBuilder<HybridQuery>> fn) {
+        return fn.apply(new HybridQuery.Builder()).build();
+    }
+
+    /**
+     * Required - list of search queries.
+     *
+     * @return list of queries provided under hybrid clause.
+     */
+    public final List<Query> queries() {
+        return this.queries;
+    }
+
+    @Override
+    protected void serializeInternal(JsonGenerator generator, JsonpMapper mapper) {
+        super.serializeInternal(generator, mapper);
+        generator.writeKey("queries");
+        generator.writeStartArray();
+        for (Query item0 : this.queries) {
+            item0.serialize(generator, mapper);
+        }
+        generator.writeEnd();
+    }
+
+    @Override
+    public Query.Kind _queryKind() {
+        return Query.Kind.Hybrid;
+    }
+
+    public HybridQuery.Builder toBuilder() {
+        return new HybridQuery.Builder().queries(queries);
+    }
+
+    public static class Builder extends QueryBase.AbstractBuilder<HybridQuery.Builder> implements ObjectBuilder<HybridQuery> {
+        private List<Query> queries;
+
+        /**
+         * API name: {@code hybrid}
+         * <p>
+         * Adds all elements of <code>list</code> to <code>hybrid</code>.
+         */
+        public final HybridQuery.Builder queries(List<Query> list) {
+            this.queries = _listAddAll(this.queries, list);
+            return this;
+        }
+
+        /**
+         * API name: {@code hybrid}
+         * <p>
+         * Adds one or more values to <code>hybrid</code>.
+         */
+        public final HybridQuery.Builder queries(Query value, Query... values) {
+            this.queries = _listAdd(this.queries, value, values);
+            return this;
+        }
+
+        /**
+         * API name: {@code hybrid}
+         * <p>
+         * Adds a value to <code>hybrid</code> using a builder lambda.
+         */
+        public final HybridQuery.Builder queries(Function<Query.Builder, ObjectBuilder<Query>> fn) {
+            return queries(fn.apply(new Query.Builder()).build());
+        }
+
+        @Override
+        protected Builder self() {
+            return this;
+        }
+
+        @Override
+        public HybridQuery build() {
+            _checkSingleUse();
+            return new HybridQuery(this);
+        }
+    }
+
+    public static final JsonpDeserializer<HybridQuery> _DESERIALIZER = ObjectBuilderDeserializer.lazy(
+        HybridQuery.Builder::new,
+        HybridQuery::setupHybridQueryDeserializer
+    );
+
+    protected static void setupHybridQueryDeserializer(ObjectDeserializer<HybridQuery.Builder> op) {
+        setupQueryBaseDeserializer(op);
+        op.add(HybridQuery.Builder::queries, JsonpDeserializer.arrayDeserializer(Query._DESERIALIZER), "queries");
+    }
+}

java-client/src/main/java/org/opensearch/client/opensearch/_types/query_dsl/Query.java

@@ -120,6 +120,8 @@ public enum Kind implements JsonEnum {
 
         Neural("neural"),
 
+        Hybrid("hybrid"),
+
         ParentId("parent_id"),
 
         Percolate("percolate"),
@@ -725,6 +727,23 @@ public NeuralQuery neural() {
         return TaggedUnionUtils.get(this, Kind.Neural);
     }
 
+    /**
+     * Is this variant instance of kind {@code hybrid}?
+     */
+    public boolean isHybrid() {
+        return _kind == Kind.Hybrid;
+    }
+
+    /**
+     * Get the {@code hybrid} variant value.
+     *
+     * @throws IllegalStateException
+     *             if the current variant is not of the {@code hybrid} kind.
+     */
+    public HybridQuery hybrid() {
+        return TaggedUnionUtils.get(this, Kind.Hybrid);
+    }
+
     /**
      * Is this variant instance of kind {@code parent_id}?
      */
@@ -1510,6 +1529,16 @@ public ObjectBuilder<Query> neural(Function<NeuralQuery.Builder, ObjectBuilder<N
             return this.neural(fn.apply(new NeuralQuery.Builder()).build());
         }
 
+        public ObjectBuilder<Query> hybrid(HybridQuery v) {
+            this._kind = Kind.Hybrid;
+            this._value = v;
+            return this;
+        }
+
+        public ObjectBuilder<Query> hybrid(Function<HybridQuery.Builder, ObjectBuilder<HybridQuery>> fn) {
+            return this.hybrid(fn.apply(new HybridQuery.Builder()).build());
+        }
+
         public ObjectBuilder<Query> parentId(ParentIdQuery v) {
             this._kind = Kind.ParentId;
             this._value = v;
@@ -1818,6 +1847,7 @@ protected static void setupQueryDeserializer(ObjectDeserializer<Builder> op) {
         op.add(Builder::multiMatch, MultiMatchQuery._DESERIALIZER, "multi_match");
         op.add(Builder::nested, NestedQuery._DESERIALIZER, "nested");
         op.add(Builder::neural, NeuralQuery._DESERIALIZER, "neural");
+        op.add(Builder::hybrid, HybridQuery._DESERIALIZER, "hybrid");
         op.add(Builder::parentId, ParentIdQuery._DESERIALIZER, "parent_id");
         op.add(Builder::percolate, PercolateQuery._DESERIALIZER, "percolate");
         op.add(Builder::pinned, PinnedQuery._DESERIALIZER, "pinned");

java-client/src/main/java/org/opensearch/client/opensearch/_types/query_dsl/QueryBuilders.java

@@ -261,6 +261,13 @@ public static NeuralQuery.Builder neural() {
         return new NeuralQuery.Builder();
     }
 
+    /**
+     * Creates a builder for the {@link HybridQuery nested} {@code Query} variant.
+     */
+    public static HybridQuery.Builder hybrid() {
+        return new HybridQuery.Builder();
+    }
+
     /**
      * Creates a builder for the {@link ParentIdQuery parent_id} {@code Query}
      * variant.

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/HybridQueryTest.java

@@ -0,0 +1,27 @@
+package org.opensearch.client.opensearch._types.query_dsl;
+
+import java.util.Arrays;
+import org.junit.Test;
+import org.opensearch.client.opensearch._types.FieldValue;
+import org.opensearch.client.opensearch.model.ModelTestCase;
+
+public class HybridQueryTest extends ModelTestCase {
+    @Test
+    public void toBuilder() {
+        HybridQuery origin = new HybridQuery.Builder().queries(
+            Arrays.asList(
+                new TermQuery.Builder().field("passage_text").value(FieldValue.of("Foo bar")).build().toQuery(),
+                new NeuralQuery.Builder().field("passage_embedding")
+                    .queryText("Hi world")
+                    .modelId("bQ1J8ooBpBj3wT4HVUsb")
+                    .k(100)
+                    .build()
+                    .toQuery(),
+                new KnnQuery.Builder().field("passage_embedding").vector(new float[] { 0.01f, 0.02f }).k(2).build().toQuery()
+            )
+        ).build();
+        HybridQuery copied = origin.toBuilder().build();
+
+        assertEquals(toJson(copied), toJson(origin));
+    }
+}

java-client/src/test/java/org/opensearch/client/opensearch/model/VariantsTest.java

@@ -32,12 +32,17 @@
 
 package org.opensearch.client.opensearch.model;
 
+import java.util.Arrays;
 import org.junit.Test;
 import org.opensearch.client.json.JsonData;
+import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch._types.mapping.Property;
 import org.opensearch.client.opensearch._types.mapping.TypeMapping;
+import org.opensearch.client.opensearch._types.query_dsl.KnnQuery;
+import org.opensearch.client.opensearch._types.query_dsl.NeuralQuery;
 import org.opensearch.client.opensearch._types.query_dsl.Query;
 import org.opensearch.client.opensearch._types.query_dsl.QueryBuilders;
+import org.opensearch.client.opensearch._types.query_dsl.TermQuery;
 import org.opensearch.client.opensearch.core.SearchRequest;
 import org.opensearch.client.opensearch.indices.GetMappingResponse;
 
@@ -243,4 +248,57 @@ public void testNeuralQueryFromJson() {
         assertEquals("bQ1J8ooBpBj3wT4HVUsb", searchRequest.query().neural().modelId());
         assertEquals(100, searchRequest.query().neural().k());
     }
+
+    @Test
+    public void testHybridQuery() {
+
+        Query query = Query.of(
+            h -> h.hybrid(
+                q -> q.queries(
+                    Arrays.asList(
+                        new TermQuery.Builder().field("passage_text").value(FieldValue.of("Foo bar")).build().toQuery(),
+                        new NeuralQuery.Builder().field("passage_embedding")
+                            .queryText("Hi world")
+                            .modelId("bQ1J8ooBpBj3wT4HVUsb")
+                            .k(100)
+                            .build()
+                            .toQuery(),
+                        new KnnQuery.Builder().field("passage_embedding").vector(new float[] { 0.01f, 0.02f }).k(2).build().toQuery()
+                    )
+                )
+            )
+        );
+        SearchRequest searchRequest = SearchRequest.of(s -> s.query(query));
+        assertEquals("passage_text", searchRequest.query().hybrid().queries().get(0).term().field());
+        assertEquals("Foo bar", searchRequest.query().hybrid().queries().get(0).term().value().stringValue());
+        assertEquals("passage_embedding", searchRequest.query().hybrid().queries().get(1).neural().field());
+        assertEquals("Hi world", searchRequest.query().hybrid().queries().get(1).neural().queryText());
+        assertEquals("bQ1J8ooBpBj3wT4HVUsb", searchRequest.query().hybrid().queries().get(1).neural().modelId());
+        assertEquals(100, searchRequest.query().hybrid().queries().get(1).neural().k());
+        assertEquals("passage_embedding", searchRequest.query().hybrid().queries().get(2).knn().field());
+        assertEquals(2, searchRequest.query().hybrid().queries().get(2).knn().vector().length);
+        assertEquals(2, searchRequest.query().hybrid().queries().get(2).knn().k());
+    }
+
+    @Test
+    public void testHybridQueryFromJson() {
+
+        String json = "{\"query\""
+            + ":{\"hybrid\":{\"queries\":[{\"term\":{\"passage_text\":\"Foo bar\"}},"
+            + "{\"neural\":{\"passage_embedding\":{\"query_text\":\"Hi world\",\"model_id\":\"bQ1J8ooBpBj3wT4HVUsb\",\"k\":100}}},"
+            + "{\"knn\":{\"passage_embedding\":{\"vector\":[0.01,0.02],\"k\":2}}}]}},\"size\":10"
+            + "}";
+
+        SearchRequest searchRequest = ModelTestCase.fromJson(json, SearchRequest.class, mapper);
+
+        assertEquals("passage_text", searchRequest.query().hybrid().queries().get(0).term().field());
+        assertEquals("Foo bar", searchRequest.query().hybrid().queries().get(0).term().value().stringValue());
+        assertEquals("passage_embedding", searchRequest.query().hybrid().queries().get(1).neural().field());
+        assertEquals("Hi world", searchRequest.query().hybrid().queries().get(1).neural().queryText());
+        assertEquals("bQ1J8ooBpBj3wT4HVUsb", searchRequest.query().hybrid().queries().get(1).neural().modelId());
+        assertEquals(100, searchRequest.query().hybrid().queries().get(1).neural().k());
+        assertEquals("passage_embedding", searchRequest.query().hybrid().queries().get(2).knn().field());
+        assertEquals(2, searchRequest.query().hybrid().queries().get(2).knn().vector().length);
+        assertEquals(2, searchRequest.query().hybrid().queries().get(2).knn().k());
+    }
 }