core: support Integer and Long in service configuration parsing

core/src/main/java/io/grpc/internal/JsonUtil.java

@@ -106,8 +106,8 @@ public static Double getNumberAsDouble(Map<String, ?> obj, String key) {
       return null;
     }
     Object value = obj.get(key);
-    if (value instanceof Double) {
-      return (Double) value;
+    if (value instanceof Number) {
+      return ((Number) value).doubleValue();
     }
     if (value instanceof String) {
       try {
@@ -132,8 +132,8 @@ public static Float getNumberAsFloat(Map<String, ?> obj, String key) {
       return null;
     }
     Object value = obj.get(key);
-    if (value instanceof Float) {
-      return (Float) value;
+    if (value instanceof Number) {
+      return ((Number) value).floatValue();
     }
     if (value instanceof String) {
       try {
@@ -159,11 +159,12 @@ public static Integer getNumberAsInteger(Map<String, ?> obj, String key) {
       return null;
     }
     Object value = obj.get(key);
-    if (value instanceof Double) {
-      Double d = (Double) value;
-      int i = d.intValue();
+    if (value instanceof Number) {
+      Number n = (Number) value;
+      double d = n.doubleValue();
+      int i = n.intValue();
       if (i != d) {
-        throw new ClassCastException("Number expected to be integer: " + d);
+        throw new ClassCastException("Number expected to be integer: " + n);
       }
       return i;
     }
@@ -190,11 +191,12 @@ public static Long getNumberAsLong(Map<String, ?> obj, String key) {
       return null;
     }
     Object value = obj.get(key);
-    if (value instanceof Double) {
-      Double d = (Double) value;
-      long l = d.longValue();
+    if (value instanceof Number) {
+      Number n = (Number) value;
+      double d = n.doubleValue();
+      long l = n.longValue();
       if (l != d) {
-        throw new ClassCastException("Number expected to be long: " + d);
+        throw new ClassCastException("Number expected to be long: " + n);
       }
       return l;
     }

core/src/main/java/io/grpc/internal/ManagedChannelImplBuilder.java

@@ -582,7 +582,7 @@ public ManagedChannelImplBuilder defaultServiceConfig(@Nullable Map<String, ?> s
         parsedMap.put(key, checkListEntryTypes((List<?>) value));
       } else if (value instanceof String) {
         parsedMap.put(key, value);
-      } else if (value instanceof Double) {
+      } else if (value instanceof Number) {
         parsedMap.put(key, value);
       } else if (value instanceof Boolean) {
         parsedMap.put(key, value);
@@ -606,7 +606,7 @@ private static List<?> checkListEntryTypes(List<?> list) {
         parsedList.add(checkListEntryTypes((List<?>) value));
       } else if (value instanceof String) {
         parsedList.add(value);
-      } else if (value instanceof Double) {
+      } else if (value instanceof Number) {
         parsedList.add(value);
       } else if (value instanceof Boolean) {
         parsedList.add(value);

core/src/test/java/io/grpc/internal/ServiceConfigNumericTypeTest.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2026, gRPC Authors All rights reserved.
+ *
+ * Licensed 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.
+ */
+
+package io.grpc.internal;
+
+import static org.junit.Assert.assertNotNull;
+
+import io.grpc.internal.ManagedChannelImplBuilder.FixedPortProvider;
+import io.grpc.internal.ManagedChannelImplBuilder.UnsupportedClientTransportFactoryBuilder;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class ServiceConfigNumericTypeTest {
+
+  @Test
+  public void defaultServiceConfig_acceptsInteger() {
+    Map<String, Object> retryPolicy = new HashMap<>();
+    retryPolicy.put("maxAttempts", 4);
+    retryPolicy.put("initialBackoff", "0.1s");
+    retryPolicy.put("maxBackoff", "1s");
+    retryPolicy.put("backoffMultiplier", 2);
+    retryPolicy.put("retryableStatusCodes", Collections.singletonList("UNAVAILABLE"));
+
+    Map<String, Object> methodConfig = new HashMap<>();
+    methodConfig.put("name", Collections.singletonList(Collections.emptyMap()));
+    methodConfig.put("retryPolicy", retryPolicy);
+
+    Map<String, Object> serviceConfig = new HashMap<>();
+    serviceConfig.put("methodConfig", Collections.singletonList(methodConfig));
+
+    ManagedChannelImplBuilder builder = new ManagedChannelImplBuilder(
+        "localhost",
+        new UnsupportedClientTransportFactoryBuilder(),
+        new FixedPortProvider(443));
+    builder.defaultServiceConfig(serviceConfig);
+    assertNotNull(builder);
+  }
+
+  @Test
+  public void defaultServiceConfig_acceptsDouble() {
+    Map<String, Object> retryPolicy = new HashMap<>();
+    retryPolicy.put("maxAttempts", 4.0);
+    retryPolicy.put("initialBackoff", "0.1s");
+    retryPolicy.put("maxBackoff", "1s");
+    retryPolicy.put("backoffMultiplier", 2.0);
+    retryPolicy.put("retryableStatusCodes", Collections.singletonList("UNAVAILABLE"));
+
+    Map<String, Object> methodConfig = new HashMap<>();
+    methodConfig.put("name", Collections.singletonList(Collections.emptyMap()));
+    methodConfig.put("retryPolicy", retryPolicy);
+
+    Map<String, Object> serviceConfig = new HashMap<>();
+    serviceConfig.put("methodConfig", Collections.singletonList(methodConfig));
+
+    ManagedChannelImplBuilder builder = new ManagedChannelImplBuilder(
+        "localhost",
+        new UnsupportedClientTransportFactoryBuilder(),
+        new FixedPortProvider(443));
+    builder.defaultServiceConfig(serviceConfig);
+    assertNotNull(builder);
+  }
+
+  @Test
+  public void defaultServiceConfig_acceptsLong() {
+    Map<String, Object> retryPolicy = new HashMap<>();
+    retryPolicy.put("maxAttempts", 4L);
+    retryPolicy.put("initialBackoff", "0.1s");
+    retryPolicy.put("maxBackoff", "1s");
+    retryPolicy.put("backoffMultiplier", 2L);
+    retryPolicy.put("retryableStatusCodes", Collections.singletonList("UNAVAILABLE"));
+
+    Map<String, Object> methodConfig = new HashMap<>();
+    methodConfig.put("name", Collections.singletonList(Collections.emptyMap()));
+    methodConfig.put("retryPolicy", retryPolicy);
+
+    Map<String, Object> serviceConfig = new HashMap<>();
+    serviceConfig.put("methodConfig", Collections.singletonList(methodConfig));
+
+    ManagedChannelImplBuilder builder = new ManagedChannelImplBuilder(
+        "localhost",
+        new UnsupportedClientTransportFactoryBuilder(),
+        new FixedPortProvider(443));
+    builder.defaultServiceConfig(serviceConfig);
+    assertNotNull(builder);
+  }
+}