modify to use URLEncodedUtils per version per Classpath

java-client/src/main/java/org/opensearch/client/transport/endpoints/SimpleEndpoint.java

@@ -32,14 +32,13 @@
 
 package org.opensearch.client.transport.endpoints;
 
-import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.Map;
 import java.util.function.Function;
 import org.opensearch.client.json.JsonpDeserializer;
 import org.opensearch.client.opensearch._types.ErrorResponse;
 import org.opensearch.client.transport.JsonEndpoint;
+import org.opensearch.client.util.PathEncoder;
 
 public class SimpleEndpoint<RequestT, ResponseT> implements JsonEndpoint<RequestT, ResponseT, ErrorResponse> {
 
@@ -134,6 +133,6 @@ public static RuntimeException noPathTemplateFound(String what) {
     }
 
     public static void pathEncode(String src, StringBuilder dest) {
-        dest.append(URLEncoder.encode(src, StandardCharsets.UTF_8));
+        dest.append(PathEncoder.encode(src));
     }
 }

java-client/src/main/java/org/opensearch/client/util/PathEncoder.java

@@ -0,0 +1,50 @@
+package org.opensearch.client.util;
+
+/*
+ * 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.
+ */
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+
+public class PathEncoder {
+
+    private final static String httpClient4UtilClassName = "org.apache.http.client.utils.URLEncodedUtils";
+    private final static String httpClient5UtilClassName = "org.apache.hc.core5.net.URLEncodedUtils";
+    private static final boolean isHttpClient5UtilPresent = isPresent(httpClient5UtilClassName);
+
+    public static String encode(String uri) {
+        if (isHttpClient5UtilPresent) {
+            return encodeByUtilClass(uri, httpClient5UtilClassName);
+        } else {
+            return encodeByUtilClass(uri, httpClient4UtilClassName);
+        }
+    }
+
+    private static String encodeByUtilClass(String uri, String className) {
+        try {
+            Method formatSegments = Class.forName(className).getMethod("formatSegments", Iterable.class, Charset.class);
+            String invoke = (String) formatSegments.invoke(null, Collections.singletonList(uri), StandardCharsets.UTF_8);
+            return invoke.substring(1);
+        } catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            throw new RuntimeException("Failed to encode URI using " + className, e);
+        }
+    }
+
+    private static boolean isPresent(String className) {
+        try {
+            Class.forName(className);
+            return true;
+        } catch (ClassNotFoundException e) {
+            return false;
+        }
+    }
+
+}

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

@@ -51,10 +51,19 @@ public void testArrayPathParameter() {
         assertEquals("/a/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
 
         req = RefreshRequest.of(b -> b.index("a", "b"));
-        assertEquals("/a%2Cb/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        if (isHttpClient5Present()) {
+            assertEquals("/a%2Cb/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+
+        } else {
+            assertEquals("/a,b/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        }
 
         req = RefreshRequest.of(b -> b.index("a", "b", "c"));
-        assertEquals("/a%2Cb%2Cc/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        if (isHttpClient5Present()) {
+            assertEquals("/a%2Cb%2Cc/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        } else {
+            assertEquals("/a,b,c/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        }
     }
 
     @Test
@@ -65,7 +74,11 @@ public void testPathEncoding() {
         assertEquals("/a%2Fb/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
 
         req = RefreshRequest.of(b -> b.index("a/b", "c/d"));
-        assertEquals("/a%2Fb%2Cc%2Fd/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        if (isHttpClient5Present()) {
+            assertEquals("/a%2Fb%2Cc%2Fd/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        } else {
+            assertEquals("/a%2Fb,c%2Fd/_refresh", RefreshRequest._ENDPOINT.requestUrl(req));
+        }
 
     }
 
@@ -84,4 +97,13 @@ public void testArrayQueryParameter() {
         req = RefreshRequest.of(b -> b.expandWildcards(ExpandWildcard.All, ExpandWildcard.Closed));
         assertEquals("all,closed", RefreshRequest._ENDPOINT.queryParameters(req).get("expand_wildcards"));
     }
+
+    private static boolean isHttpClient5Present() {
+        try {
+            Class.forName("org.apache.hc.core5.net.URLEncodedUtils");
+            return true;
+        } catch (ClassNotFoundException e) {
+            return false;
+        }
+    }
 }

java-client/src/test/java/org/opensearch/client/util/PathEncoderTest.java

@@ -0,0 +1,31 @@
+package org.opensearch.client.util;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class PathEncoderTest {
+
+    @Test
+    public void testEncode() {
+        // Test with a simple string
+        String simpleString = "test";
+        String encodedSimpleString = PathEncoder.encode(simpleString);
+        assertEquals(simpleString, encodedSimpleString);
+
+        // Test with a string that contains special characters
+        String specialString = "a/b";
+        String encodedSpecialString = PathEncoder.encode(specialString);
+        assertEquals("a%2Fb", encodedSpecialString);
+
+        // Test with a string that contains alphanumeric characters
+        String alphanumericString = "abc123";
+        String encodedAlphanumericString = PathEncoder.encode(alphanumericString);
+        assertEquals("abc123", encodedAlphanumericString);
+
+        // Test with a string that contains multiple segments
+        String multiSegmentString = "a/b/c/_refresh";
+        String encodedMultiSegmentString = PathEncoder.encode(multiSegmentString);
+        assertEquals("a%2Fb%2Fc%2F_refresh", encodedMultiSegmentString);
+    }
+}