588 - [FEATURE] serialize requests to JSON

CHANGELOG.md

@@ -11,6 +11,7 @@ This section is for maintaining a changelog for all breaking changes for the cli
 
 ### Added
 - Document HTTP/2 support ([#330](https://github.com/opensearch-project/opensearch-java/pull/330))
+- Add a serializer method for classes implementing JsonpSerializable.
 
 ### Dependencies
 

java-client/src/main/java/org/opensearch/client/json/JsonpSerializable.java

@@ -33,11 +33,33 @@
 package org.opensearch.client.json;
 
 import jakarta.json.stream.JsonGenerator;
+import org.opensearch.client.json.jackson.JacksonJsonProvider;
+import org.opensearch.client.json.jackson.JacksonJsonpMapper;
+
+import java.io.StringWriter;
 
 /**
  * An object that is its own JsonP serializer
  */
 public interface JsonpSerializable {
 
     void serialize(JsonGenerator generator, JsonpMapper mapper);
+
+
+    /**
+     * A default method which returns string representation for the instances of classes
+     * implementing JsonpSerializable interface.<br>
+     * Usage : Eg for SearchRequest.class<pre>{@code SearchRequest implements JsonpSerializable{..}
+     * SearchRequest searchRequest = SearchRequest.of(request -> request...);
+     * String searchRequestString = searchRequest.writeValueAsString();}</pre>  <br>
+     *
+     */
+    default String writeValueAsString() {
+        StringWriter writer = new StringWriter();
+        try (JsonGenerator generator = JacksonJsonProvider.provider().createGenerator(writer)) {
+            serialize(generator, new JacksonJsonpMapper());
+        };
+        return writer.toString();
+    }
+
 }

java-client/src/test/java/org/opensearch/client/opensearch/json/JsonpSerializableTest.java

@@ -0,0 +1,100 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Modifications Copyright OpenSearch Contributors. See
+ * GitHub history for details.
+ */
+
+package org.opensearch.client.opensearch.json;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.opensearch.client.opensearch._types.FieldValue;
+import org.opensearch.client.opensearch._types.Result;
+import org.opensearch.client.opensearch.core.IndexResponse;
+import org.opensearch.client.opensearch.core.SearchRequest;
+import org.opensearch.client.util.MissingRequiredPropertyException;
+
+import java.util.Collections;
+
+public class JsonpSerializableTest extends Assert {
+
+    // Test IndexResponse which extends WriteResponseBase which implements JsonpSerializable
+    @Test
+    public void testIndexResponse() {
+
+        String expectedStringValue = "{\"_id\":\"id\",\"_index\":\"index\",\"_primary_term\":1,\"result\":\"created\",\"_seq_no\":2,\"_shards\":{\"failed\":1.0,\"successful\":1.0,\"total\":3.0,\"failures\":[{\"index\":\"index\",\"node\":\"node\",\"reason\":{\"type\":\"query_shard_exception\",\"reason\":\"Failed to create query.\"},\"shard\":1,\"status\":\"Failed\"}],\"skipped\":1.0},\"_version\":3}";
+        IndexResponse indexResponse = IndexResponse.of(response -> response
+                .result(Result.Created)
+                .index("index")
+                .id("id")
+                .primaryTerm(1)
+                .seqNo(2)
+                .version(3)
+                .shards(shardStats -> shardStats
+                        .total(3)
+                        .successful(1)
+                        .skipped(1)
+                        .failed(1)
+                        .failures(shardFailure->shardFailure
+                                .index("index")
+                                .node("node")
+                                .shard(1)
+                                .status("Failed")
+                                .reason(cause->cause
+                                        .type("query_shard_exception")
+                                        .reason("Failed to create query.")
+                                )
+                        )
+                )
+        );
+
+        String indexResponseString = indexResponse.writeValueAsString();
+        assertEquals(expectedStringValue, indexResponseString);
+    }
+
+    // Test SearchRequest which implements JsonpSerializable
+    @Test
+    public void testSearchResponse() {
+
+        String expectedStringValue = "{\"aggregations\":{},\"query\":{\"match\":{\"name\":{\"query\":\"OpenSearch\"}}},\"terminate_after\":5}";
+        SearchRequest searchRequest = SearchRequest.of(request -> request
+                .index("index1","index2")
+                .aggregations(Collections.emptyMap())
+                .terminateAfter(5L)
+                .query(q -> q
+                        .match(t -> t
+                                .field("name")
+                                .query(FieldValue.of("OpenSearch"))
+                        )
+                )
+        );
+        String searchRequestString = searchRequest.writeValueAsString();
+        assertEquals(expectedStringValue, searchRequestString);
+
+    }
+
+}