Add HttpExchangeAdapter decoration

Closes gh-35059

spring-web/src/test/java/org/springframework/web/service/invoker/HttpServiceProxyFactoryTests.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.web.service.invoker;
+
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.web.service.annotation.GetExchange;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit tests for {@link HttpServiceProxyFactory}.
+ * @author Rossen Stoyanchev
+ */
+public class HttpServiceProxyFactoryTests {
+
+
+	@Test
+	void httpExchangeAdapterDecorator() {
+
+		HttpServiceProxyFactory factory = HttpServiceProxyFactory.builderFor(mock(HttpExchangeAdapter.class))
+				.exchangeAdapterDecorator(TestDecorator::new)
+				.build();
+
+		Service service = factory.createClient(Service.class);
+		assertThat(service.execute()).isEqualTo("decorated");
+	}
+
+
+
+	private interface Service {
+
+		@GetExchange
+		String execute();
+	}
+
+
+	private static class TestDecorator extends HttpExchangeAdapterDecorator {
+
+		public TestDecorator(HttpExchangeAdapter delegate) {
+			super(delegate);
+		}
+
+		@SuppressWarnings("unchecked")
+		@Override
+		public <T> @Nullable T exchangeForBody(HttpRequestValues values, ParameterizedTypeReference<T> bodyType) {
+			return (T) "decorated";
+		}
+	}
+
+}