Added High Level Rest Client for SDK

Signed-off-by: Owais Kazi <owaiskazi19@gmail.com>

build.gradle

@@ -79,6 +79,7 @@ dependencies {
     implementation("org.opensearch:opensearch:${opensearchVersion}")
     implementation("org.apache.logging.log4j:log4j-api:${log4jVersion}")
     implementation("org.apache.logging.log4j:log4j-core:${log4jVersion}")
+    implementation ("org.opensearch.client:opensearch-rest-high-level-client:${opensearchVersion}")
     implementation("org.opensearch.client:opensearch-rest-client:${opensearchVersion}")
     implementation("org.opensearch.client:opensearch-java:${opensearchVersion}")
     implementation("org.opensearch.plugin:transport-netty4-client:${opensearchVersion}")

src/main/java/org/opensearch/sdk/SDKClient.java

@@ -28,6 +28,7 @@
 import org.apache.hc.core5.ssl.SSLContextBuilder;
 import org.opensearch.client.RestClient;
 import org.opensearch.client.RestClientBuilder;
+import org.opensearch.client.RestHighLevelClient;
 import org.opensearch.client.json.jackson.JacksonJsonpMapper;
 import org.opensearch.client.opensearch.OpenSearchClient;
 import org.opensearch.client.transport.OpenSearchTransport;
@@ -41,14 +42,9 @@
 public class SDKClient {
     private OpenSearchClient javaClient;
     private RestClient restClient = null;
+    private RestHighLevelClient highLevelClient;
 
-    /**
-     * Creates OpenSearchClient for SDK. It also creates a restClient as a wrapper around Java OpenSearchClient
-     * @param hostAddress The address of OpenSearch cluster, client can connect to
-     * @param port The port of OpenSearch cluster
-     * @return SDKClient which is internally an OpenSearchClient. The user is responsible for calling {@link #doCloseRestClient()} when finished with the client
-     */
-    public OpenSearchClient initializeClient(String hostAddress, int port) {
+    private RestClientBuilder builder(String hostAddress, int port) {
         RestClientBuilder builder = RestClient.builder(new HttpHost(hostAddress, port));
         builder.setStrictDeprecationMode(true);
         builder.setHttpClientConfigCallback(httpClientBuilder -> {
@@ -74,6 +70,17 @@ public TlsDetails create(final SSLEngine sslEngine) {
                 throw new RuntimeException(e);
             }
         });
+        return builder;
+    }
+
+    /**
+     * Creates OpenSearchClient for SDK. It also creates a restClient as a wrapper around Java OpenSearchClient
+     * @param hostAddress The address of OpenSearch cluster, client can connect to
+     * @param port The port of OpenSearch cluster
+     * @return SDKClient which is internally an OpenSearchClient. The user is responsible for calling {@link #doCloseRestClient()} when finished with the client
+     */
+    public OpenSearchClient initializeJavaClient(String hostAddress, int port) {
+        RestClientBuilder builder = builder(hostAddress, port);
 
         restClient = builder.build();
 
@@ -91,7 +98,20 @@ public TlsDetails create(final SSLEngine sslEngine) {
     }
 
     /**
-     * Close this client.
+     * Creates High Level Rest Client for SDK.
+     * @param hostAddress The address of OpenSearch cluster, client can connect to
+     * @param port The port of OpenSearch cluster
+     * @return SDKClient which is internally an RestHighLevelClient. The user is responsible for calling {@link #doCloseRestClient()} when finished with the client
+     */
+    public RestHighLevelClient initializeRestClient(String hostAddress, int port) {
+        RestClientBuilder builder = builder(hostAddress, port);
+
+        highLevelClient = new RestHighLevelClient(builder);
+        return highLevelClient;
+    }
+
+    /**
+     * Close java client.
      *
      * @throws IOException if closing the restClient fails
      */
@@ -100,4 +120,15 @@ public void doCloseRestClient() throws IOException {
             restClient.close();
         }
     }
+
+    /**
+     * Close high level rest client.
+     *
+     * @throws IOException if closing the highLevelClient fails
+     */
+    public void doCloseHLRClient() throws IOException {
+        if (highLevelClient != null) {
+            highLevelClient.close();
+        }
+    }
 }

src/test/java/org/opensearch/sdk/TestSDKClient.java

@@ -10,6 +10,8 @@
 package org.opensearch.sdk;
 
 import org.junit.jupiter.api.Test;
+import org.opensearch.client.RequestOptions;
+import org.opensearch.client.RestHighLevelClient;
 import org.opensearch.client.opensearch.OpenSearchClient;
 import org.opensearch.client.opensearch.indices.Alias;
 import org.opensearch.client.opensearch.indices.CreateIndexRequest;
@@ -23,9 +25,9 @@ public class TestSDKClient extends OpenSearchTestCase {
     SDKClient sdkClient = new SDKClient();
 
     @Test
-    public void testCreateClient() throws Exception {
+    public void testCreateJavaClient() throws Exception {
 
-        OpenSearchClient testClient = sdkClient.initializeClient("localhost", 9200);
+        OpenSearchClient testClient = sdkClient.initializeJavaClient("localhost", 9200);
         assertInstanceOf(OpenSearchClient.class, testClient);
 
         assertThrows(
@@ -41,4 +43,19 @@ public void testCreateClient() throws Exception {
         sdkClient.doCloseRestClient();
     }
 
+    @Test
+    public void testCreateHighLevelRestClient() throws Exception {
+        RestHighLevelClient testClient = sdkClient.initializeRestClient("localhost", 9200);
+
+        // Using the package name here as Java uses package name if the filename from different packages are same
+        org.opensearch.client.indices.CreateIndexRequest createIndexRequest = new org.opensearch.client.indices.CreateIndexRequest(
+            "my-index"
+        );
+
+        assertThrows(ConnectException.class, () -> testClient.indices().create(createIndexRequest, RequestOptions.DEFAULT));
+
+        sdkClient.doCloseHLRClient();
+
+    }
+
 }