Add sample to create the client via dynamic proxy

CHANGELOG.md

@@ -18,7 +18,7 @@ This section is for maintaining a changelog for all breaking changes for the cli
 - Document HTTP/2 support ([#330](https://github.com/opensearch-project/opensearch-java/pull/330))
 - Expose HTTP status code through `ResponseException#status` ([#756](https://github.com/opensearch-project/opensearch-java/pull/756))
 - Added missing WrapperQuery accessors and builder methods ([#806](https://github.com/opensearch-project/opensearch-java/pull/806))
-
+- Added a sample for creating OpenSearchClient via dynamic proxy ([#847](https://github.com/opensearch-project/opensearch-java/pull/847))
 
 ### Dependencies
 

samples/build.gradle.kts

@@ -24,6 +24,7 @@ dependencies {
     implementation("org.apache.logging.log4j", "log4j-slf4j2-impl","[2.17.1,3.0)")
     implementation("commons-logging", "commons-logging", "1.2")
     implementation("com.fasterxml.jackson.core", "jackson-databind", "2.15.2")
+    implementation("cglib", "cglib", "3.3.0")
 }
 
 spotless {

samples/src/main/java/org/opensearch/client/samples/OpenSearchClientProxy.java

@@ -0,0 +1,58 @@
+/*
+ * 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.
+ */
+
+package org.opensearch.client.samples;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import net.sf.cglib.proxy.Enhancer;
+import net.sf.cglib.proxy.MethodInterceptor;
+import net.sf.cglib.proxy.MethodProxy;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.client.opensearch.OpenSearchClient;
+import org.opensearch.client.transport.OpenSearchTransport;
+
+public class OpenSearchClientProxy implements MethodInterceptor {
+
+    private static final Logger LOGGER = LogManager.getLogger(OpenSearchClientProxy.class);
+
+    public static OpenSearchClient create(OpenSearchTransport transport) throws Exception {
+        if (transport == null) {
+            throw new Exception("Cannot build OpenSearchClient without a transport.");
+        }
+
+        LOGGER.info("Using {} transport", transport.getClass().getName());
+
+        final var interceptor = new OpenSearchClientProxy();
+        final var enhancer = new Enhancer();
+
+        enhancer.setSuperclass(OpenSearchClient.class);
+        enhancer.setCallback(interceptor);
+
+        final var argTypes = new Class[] { OpenSearchTransport.class };
+        final var args = new Object[] { transport };
+        return (OpenSearchClient) enhancer.create(argTypes, args);
+    }
+
+    @Override
+    public Object intercept(final Object obj, final Method method, final Object[] args, final MethodProxy proxy) throws Throwable {
+        LOGGER.info("Invoking method: {}", method.getName());
+        final Object result;
+
+        try {
+            LOGGER.info("Entering method: {}", method.getName());
+            result = proxy.invokeSuper(obj, args);
+        } catch (final InvocationTargetException e) {
+            throw e.getTargetException();
+        } finally {
+            LOGGER.info("Exiting method: {}", method.getName());
+        }
+        return result;
+    }
+}

samples/src/main/java/org/opensearch/client/samples/SampleClient.java

@@ -21,10 +21,12 @@
 import org.apache.hc.core5.ssl.SSLContextBuilder;
 import org.opensearch.client.json.jackson.JacksonJsonpMapper;
 import org.opensearch.client.opensearch.OpenSearchClient;
+import org.opensearch.client.transport.OpenSearchTransport;
 import org.opensearch.client.transport.httpclient5.ApacheHttpClient5TransportBuilder;
 
 public class SampleClient {
-    public static OpenSearchClient create() throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
+
+    public static OpenSearchTransport createTransport() throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
         var env = System.getenv();
         var https = Boolean.parseBoolean(env.getOrDefault("HTTPS", "true"));
         var hostname = env.getOrDefault("HOST", "localhost");
@@ -36,7 +38,7 @@ public static OpenSearchClient create() throws NoSuchAlgorithmException, KeyStor
 
         final var sslContext = SSLContextBuilder.create().loadTrustMaterial(null, (chains, authType) -> true).build();
 
-        final var transport = ApacheHttpClient5TransportBuilder.builder(hosts)
+        return ApacheHttpClient5TransportBuilder.builder(hosts)
             .setMapper(new JacksonJsonpMapper())
             .setHttpClientConfigCallback(httpClientBuilder -> {
                 final var credentialsProvider = new BasicCredentialsProvider();
@@ -55,6 +57,9 @@ public static OpenSearchClient create() throws NoSuchAlgorithmException, KeyStor
                 return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider).setConnectionManager(connectionManager);
             })
             .build();
-        return new OpenSearchClient(transport);
+    }
+
+    public static OpenSearchClient create() throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
+        return new OpenSearchClient(createTransport());
     }
 }

samples/src/main/java/org/opensearch/client/samples/SampleProxyClient.java

@@ -0,0 +1,73 @@
+package org.opensearch.client.samples;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.client.opensearch._types.mapping.IntegerNumberProperty;
+import org.opensearch.client.opensearch._types.mapping.Property;
+import org.opensearch.client.opensearch._types.mapping.TypeMapping;
+import org.opensearch.client.opensearch.core.IndexRequest;
+import org.opensearch.client.opensearch.core.SearchResponse;
+import org.opensearch.client.opensearch.indices.CreateIndexRequest;
+import org.opensearch.client.opensearch.indices.DeleteIndexRequest;
+import org.opensearch.client.opensearch.indices.IndexSettings;
+import org.opensearch.client.samples.util.IndexData;
+
+/**
+ * Run with: <c>./gradlew :samples:run -Dsamples.mainClass=SampleProxyClient</c>
+ */
+public class SampleProxyClient {
+
+    private static final Logger LOGGER = LogManager.getLogger(SampleProxyClient.class);
+
+    public static void main(String[] args) {
+        try {
+            var transport = SampleClient.createTransport();
+            var client = OpenSearchClientProxy.create(transport);
+
+            final var indexName = "my-index";
+
+            if (!client.indices().exists(r -> r.index(indexName)).value()) {
+                LOGGER.info("Creating index {}", indexName);
+                IndexSettings settings = new IndexSettings.Builder().numberOfShards("2").numberOfReplicas("1").build();
+                TypeMapping mapping = new TypeMapping.Builder().properties(
+                    "age",
+                    new Property.Builder().integer(new IntegerNumberProperty.Builder().build()).build()
+                ).build();
+                CreateIndexRequest createIndexRequest = new CreateIndexRequest.Builder().index(indexName)
+                    .settings(settings)
+                    .mappings(mapping)
+                    .build();
+                client.indices().create(createIndexRequest);
+            }
+
+            LOGGER.info("Indexing documents");
+            IndexData indexData = new IndexData("Document 1", "Text for document 1");
+            IndexRequest<IndexData> indexRequest = new IndexRequest.Builder<IndexData>().index(indexName)
+                .id("1")
+                .document(indexData)
+                .build();
+            client.index(indexRequest);
+
+            indexData = new IndexData("Document 2", "Text for document 2");
+            indexRequest = new IndexRequest.Builder<IndexData>().index(indexName).id("2").document(indexData).build();
+            client.index(indexRequest);
+
+            // wait for the document to index
+            Thread.sleep(3000);
+
+            SearchResponse<IndexData> searchResponse = client.search(s -> s.index(indexName), IndexData.class);
+            for (var hit : searchResponse.hits().hits()) {
+                LOGGER.info("Found {} with score {}", hit.source(), hit.score());
+            }
+
+            LOGGER.info("Deleting document with id 1");
+            client.delete(d -> d.index(indexName).id("1"));
+
+            LOGGER.info("Deleting index {}", indexName);
+            DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest.Builder().index(indexName).build();
+            client.indices().delete(deleteIndexRequest);
+        } catch (Exception e) {
+            LOGGER.error("Unexpected exception", e);
+        }
+    }
+}