INT-4018: Resolve some TODOs

JIRA: https://jira.spring.io/browse/INT-4018

* Resolve some TODOs as expected
* Remove some as logically or physically with useless effort
* Leave others for future considerations

spring-integration-core/src/test/java/org/springframework/integration/aggregator/MethodInvokingReleaseStrategyTests.java

@@ -178,7 +178,6 @@ public class MethodInvokingReleaseStrategyTests {
 				return false;
 			}
 		}
-		// TODO: this is stupid, but maybe it should be illegal?
 		new MethodInvokingReleaseStrategy(new TestReleaseStrategy(), "notEnoughParameters");
 	}
 
@@ -190,7 +189,6 @@ public class MethodInvokingReleaseStrategyTests {
 				return false;
 			}
 		}
-		// TODO: this is stupid, but maybe it should be illegal?
 		new MethodInvokingReleaseStrategy(new TestReleaseStrategy(), TestReleaseStrategy.class.getMethod(
 				"notEnoughParameters"));
 	}
@@ -208,7 +206,6 @@ public class MethodInvokingReleaseStrategyTests {
 		Assert.assertTrue(adapter.canRelease(messages));
 	}
 
-	// TODO: should this be MessageHandlingException?
 	@Test(expected = ConversionFailedException.class)
 	public void testWrongReturnType() throws SecurityException, NoSuchMethodError {
 		class TestReleaseStrategy {
@@ -248,7 +245,6 @@ public class MethodInvokingReleaseStrategyTests {
 		Assert.assertTrue(adapter.canRelease(messages));
 	}
 
-	// TODO: review exception type here
 	@Test(expected = IllegalStateException.class)
 	public void testWrongReturnTypeUsingMethodObject() throws SecurityException, NoSuchMethodException {
 		class TestReleaseStrategy {

spring-integration-file/src/main/java/org/springframework/integration/file/remote/gateway/AbstractRemoteFileOutboundGateway.java

@@ -37,6 +37,7 @@ import org.springframework.expression.common.LiteralExpression;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.integration.IntegrationMessageHeaderAccessor;
 import org.springframework.integration.expression.ExpressionUtils;
+import org.springframework.integration.expression.FunctionExpression;
 import org.springframework.integration.file.FileHeaders;
 import org.springframework.integration.file.filters.FileListFilter;
 import org.springframework.integration.file.remote.AbstractFileInfo;
@@ -60,6 +61,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Gary Russell
  * @author Artem Bilan
+ *
  * @since 2.1
  */
 public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReplyProducingMessageHandler {
@@ -209,7 +211,8 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private volatile ExpressionEvaluatingMessageProcessor<String> renameProcessor =
 			new ExpressionEvaluatingMessageProcessor<>(
-					new SpelExpressionParser().parseExpression("headers." + FileHeaders.RENAME_TO));
+					new FunctionExpression<Message<?>>(m ->
+							m.getHeaders().get(FileHeaders.RENAME_TO)));
 
 	private volatile Expression localDirectoryExpression;
 
@@ -592,7 +595,6 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 		return getMessageBuilderFactory().withPayload(payload)
 				.setHeader(FileHeaders.REMOTE_DIRECTORY, remoteDir)
 				.setHeader(FileHeaders.REMOTE_FILE, remoteFilename)
-				.setHeader("file_remoteSession", session) // TODO: remove in 5.0
 				.setHeader(IntegrationMessageHeaderAccessor.CLOSEABLE_RESOURCE, session)
 				.build();
 	}
@@ -861,7 +863,7 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 		boolean exists = localFile.exists();
 		boolean replacing = FileExistsMode.REPLACE.equals(fileExistsMode)
 				|| (exists && FileExistsMode.REPLACE_IF_MODIFIED.equals(fileExistsMode)
-						&& localFile.lastModified() != getModified(fileInfo));
+				&& localFile.lastModified() != getModified(fileInfo));
 		if (!exists || appending || replacing) {
 			OutputStream outputStream;
 			String tempFileName = localFile.getAbsolutePath() + this.remoteFileTemplate.getTemporaryFileSuffix();

spring-integration-ftp/src/test/java/org/springframework/integration/ftp/outbound/FtpServerOutboundTests-context.xml

@@ -131,7 +131,7 @@
 	</int:chain>
 
 	<int:service-activator input-channel="markers"
-	  expression="headers['file_marker']?.equals('END') ? headers['file_remoteSession'].close() : null"/>
+	  expression="headers['file_marker']?.equals('END') ? headers['closeableResource'].close() : null"/>
 
 	<int:channel id="appending" />
 

spring-integration-jpa/src/main/java/org/springframework/integration/jpa/support/JpaParameter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -25,8 +25,6 @@ import org.springframework.util.Assert;
  * Abstraction of Jpa parameters allowing to provide static parameters
  * and SpEl Expression based parameters.
  *
- * TODO Should we combine ProcedureParameter class and this class?
- *
  * @author Gunnar Hillert
  * @author Artem Bilan
  * @author Gary Russell

spring-integration-sftp/src/test/java/org/springframework/integration/sftp/outbound/SftpServerOutboundTests-context.xml

@@ -162,7 +162,7 @@
 	</int:chain>
 
 	<int:service-activator input-channel="markers"
-	  expression="payload.mark.toString().equals('END') ? headers['file_remoteSession'].close() : null"/>
+	  expression="payload.mark.toString().equals('END') ? headers['closeableResource'].close() : null"/>
 
 	<int-sftp:outbound-gateway
 			session-factory="sftpSessionFactory"

spring-integration-stomp/src/test/java/org/springframework/integration/stomp/inbound/StompInboundChannelAdapterWebSocketIntegrationTests.java

@@ -352,7 +352,7 @@ public class StompInboundChannelAdapterWebSocketIntegrationTests extends LogAdju
 					.enableSimpleBroker("/topic", "/queue");
 		}
 
-		//TODO SimpleBrokerMessageHandler doesn't support RECEIPT frame, hence we emulate it this way
+		//SimpleBrokerMessageHandler doesn't support RECEIPT frame, hence we emulate it this way
 		@Bean
 		public ApplicationListener<SessionSubscribeEvent> webSocketEventListener(
 				final AbstractSubscribableChannel clientOutboundChannel) {

spring-integration-websocket/src/test/java/org/springframework/integration/websocket/client/StompIntegrationTests.java

@@ -487,7 +487,7 @@ public class StompIntegrationTests extends LogAdjustingTestSupport {
 			configurer.enableSimpleBroker("/topic", "/queue");
 		}
 
-		//TODO SimpleBrokerMessageHandler doesn't support RECEIPT frame, hence we emulate it this way
+		//SimpleBrokerMessageHandler doesn't support RECEIPT frame, hence we emulate it this way
 		@Bean
 		public ApplicationListener<SessionSubscribeEvent> webSocketEventListener(
 				final AbstractSubscribableChannel clientOutboundChannel) {