INT-3052 RestTemplate with TypeReference for HTTP

JIRA: https://jira.springsource.org/browse/INT-3052

Add support of `ParameterizedTypeReference` as a result of
`expectedResponseTypeExpression` evaluation for
`RestTemplate.exchange` with `ParameterizedTypeReference` parameter

Now `expectedResponseTypeExpression` can be evaluated to `Class<?>`,
`String` and `ParameterizedTypeReference<?>`

spring-integration-http/src/test/java/org/springframework/integration/http/config/OutboundResponseTypeTests-context.xml

@@ -36,6 +36,11 @@
 							   message-converters="stringAndSerializingConverters"
 							   expected-response-type-expression="payload"/>
 
+	<int-http:outbound-gateway url="http://localhost:#{portBean.port}/testApps/outboundResponse"
+							   request-channel="invalidResponseTypeChannel"
+							   expected-response-type-expression="new java.util.Date()"/>
+
+
 	<util:list id="stringAndSerializingConverters">
 		<bean class="org.springframework.integration.http.converter.SerializingHttpMessageConverter" />
 		<bean class="org.springframework.http.converter.StringHttpMessageConverter" />

spring-integration-http/src/test/java/org/springframework/integration/http/config/OutboundResponseTypeTests.java

@@ -16,6 +16,7 @@
 package org.springframework.integration.http.config;
 
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -23,21 +24,24 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.net.InetSocketAddress;
 
+import org.hamcrest.Matchers;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.parsing.BeanDefinitionParsingException;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
+import org.springframework.integration.MessageHandlingException;
+import org.springframework.integration.channel.QueueChannel;
+import org.springframework.integration.test.util.SocketUtils;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
-import org.springframework.integration.channel.QueueChannel;
 import org.springframework.messaging.support.GenericMessage;
-import org.springframework.integration.test.util.SocketUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -80,6 +84,9 @@ public class OutboundResponseTypeTests {
 	@Autowired
 	private MessageChannel resTypeExpressionSetSerializationChannel;
 
+	@Autowired
+	private MessageChannel invalidResponseTypeChannel;
+
 	private static int port = SocketUtils.findAvailableServerSocket();
 
 	@BeforeClass
@@ -143,6 +150,21 @@ public class OutboundResponseTypeTests {
 		assertTrue(message.getPayload() instanceof byte[]);
 	}
 
+	@Test
+	public void testInt3052InvalidResponseType() throws Exception {
+		try {
+			this.invalidResponseTypeChannel.send(new GenericMessage<byte[]>("hello".getBytes()));
+			fail("IllegalArgumentException expected.");
+		}
+		catch (Exception e) {
+			assertThat(e, Matchers.instanceOf(MessageHandlingException.class));
+			Throwable t = e.getCause();
+			assertThat(t, Matchers.instanceOf(IllegalArgumentException.class));
+			assertThat(t.getMessage(),
+					Matchers.containsString("'expectedResponseType' can be an instance of 'Class<?>', 'String' or 'ParameterizedTypeReference<?>'"));
+		}
+	}
+
 	@Test
 	public void testMutuallyExclusivityInMethodAndMethodExpression() throws Exception {
 		try {

spring-integration-http/src/test/java/org/springframework/integration/http/outbound/HttpOutboundWithinChainTests-context.xml

@@ -22,7 +22,7 @@
 		<outbound-gateway url="http://localhost:51235/%2f/testApps?param={param}"
 						  rest-template="restTemplate"
 						  encode-uri="false"
-						  expected-response-type="java.lang.String">
+						  expected-response-type-expression="T (org.springframework.integration.http.outbound.HttpRequestExecutingMessageHandlerTests).testParameterizedTypeReference()">
 			<uri-variable name="param" expression="T(org.apache.commons.httpclient.util.URIUtil).encodeWithinQuery('http Outbound Gateway Within Chain')"/>
 						  </outbound-gateway>
 	</si:chain>

spring-integration-http/src/test/java/org/springframework/integration/http/outbound/HttpRequestExecutingMessageHandlerTests.java

@@ -52,6 +52,7 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.ConverterRegistry;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
@@ -65,14 +66,14 @@ import org.springframework.http.client.ClientHttpRequest;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.http.converter.HttpMessageConverter;
-import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageChannel;
 import org.springframework.integration.channel.QueueChannel;
-import org.springframework.messaging.PollableChannel;
 import org.springframework.integration.http.converter.SerializingHttpMessageConverter;
-import org.springframework.messaging.support.GenericMessage;
 import org.springframework.integration.support.MessageBuilder;
 import org.springframework.integration.test.util.TestUtils;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.PollableChannel;
+import org.springframework.messaging.support.GenericMessage;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
@@ -86,6 +87,10 @@ import org.springframework.web.client.RestTemplate;
  */
 public class HttpRequestExecutingMessageHandlerTests {
 
+	public static ParameterizedTypeReference<List<String>> testParameterizedTypeReference() {
+		return new ParameterizedTypeReference<List<String>>() {};
+	}
+
 	@Test
 	public void simpleStringKeyStringValueFormData() throws Exception {
 		HttpRequestExecutingMessageHandler handler = new HttpRequestExecutingMessageHandler("http://www.springsource.org/spring-integration");
@@ -726,10 +731,12 @@ public class HttpRequestExecutingMessageHandlerTests {
 
 		PollableChannel output = ctx.getBean("replyChannel", PollableChannel.class);
 		Message<?> receive = output.receive();
-		assertEquals(HttpStatus.OK, ((ResponseEntity<?>)receive.getPayload()).getStatusCode());
+		assertEquals(HttpStatus.OK, ((ResponseEntity<?>) receive.getPayload()).getStatusCode());
 		Mockito.verify(restTemplate)
 				.exchange(Mockito.eq(new URI("http://localhost:51235/%2f/testApps?param=http%20Outbound%20Gateway%20Within%20Chain")),
-				Mockito.eq(HttpMethod.POST), Mockito.any(HttpEntity.class), Mockito.eq(String.class));
+						Mockito.eq(HttpMethod.POST), Mockito.any(HttpEntity.class), Mockito.eq(new ParameterizedTypeReference<List<String>>() {
+
+				}));
 	}
 
 	@Test
@@ -938,6 +945,12 @@ public class HttpRequestExecutingMessageHandlerTests {
 											  Class<T> responseType) throws RestClientException {
 			return new ResponseEntity<T>(HttpStatus.OK);
 		}
+
+		@Override
+		public <T> ResponseEntity<T> exchange(URI url, HttpMethod method, HttpEntity<?> requestEntity,
+											  ParameterizedTypeReference<T> responseType) throws RestClientException {
+			return new ResponseEntity<T>(HttpStatus.OK);
+		}
 	}
 
 	private static class Foo implements Serializable {