INT-3919: FTP: Allow null for Remote Directory

JIRA: https://jira.spring.io/browse/INT-3919

Since `FtpClient` supports `null` for the `LS` command, treating it as a current `working directory`,
there is no reason to forbid `null` from the FTP adapters end-user perspective.

* Allow `null` for the `FtpSession` `list()` and `listNames()` methods
* Allow `null` in the `remote-directory` for the `<int-ftp:inbound-channel-adapter>`
* Allow `null` in the `expression` for the `FtpOutboundGateway`

Polishing - send error if error on async output

Cover `onFailure()` from `onSuccess()` with the `errorChannel`

Address PR Comments

* Get rid of `null` population for the `remoteDirectoryExpression` in the `AbstractPollingInboundChannelAdapterParser`
* Populate `new LiteralExpression(null)` from the `FtpInboundFileSynchronizer` ctor
* Introduce `buildRemotePath(parent, child)` function in the `AbstractRemoteFileOutboundGateway` with the `null` logic for `parent`
* Rework `mGetWithoutRecursion()` to use `LS` command and allow `null` for the dir.
* Fix tests according the new `mGetWithoutRecursion()` logic

Polishing

spring-integration-file/src/main/java/org/springframework/integration/file/config/AbstractRemoteFileInboundChannelAdapterParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -33,6 +33,7 @@ import org.springframework.util.StringUtils;
  * @author Oleg Zhurakousky
  * @author Mark Fisher
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 2.0
  */
 public abstract class AbstractRemoteFileInboundChannelAdapterParser extends AbstractPollingInboundChannelAdapterParser {
@@ -46,8 +47,10 @@ public abstract class AbstractRemoteFileInboundChannelAdapterParser extends Abst
 
 		// configure the InboundFileSynchronizer properties
 		BeanDefinition expressionDef = IntegrationNamespaceUtils.createExpressionDefinitionFromValueOrExpression(
-				"remote-directory", "remote-directory-expression", parserContext, element, true);
-		synchronizerBuilder.addPropertyValue("remoteDirectoryExpression", expressionDef);
+				"remote-directory", "remote-directory-expression", parserContext, element, false);
+		if (expressionDef != null) {
+			synchronizerBuilder.addPropertyValue("remoteDirectoryExpression", expressionDef);
+		}
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(synchronizerBuilder, element, "delete-remote-files");
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(synchronizerBuilder, element, "preserve-timestamp");
 
@@ -57,7 +60,8 @@ public abstract class AbstractRemoteFileInboundChannelAdapterParser extends Abst
 		this.configureFilter(synchronizerBuilder, element, parserContext);
 
 		// build the MessageSource
-		BeanDefinitionBuilder messageSourceBuilder = BeanDefinitionBuilder.genericBeanDefinition(this.getMessageSourceClassname());
+		BeanDefinitionBuilder messageSourceBuilder =
+				BeanDefinitionBuilder.genericBeanDefinition(getMessageSourceClassname());
 		messageSourceBuilder.addConstructorArgValue(synchronizerBuilder.getBeanDefinition());
 		String comparator = element.getAttribute("comparator");
 		if (StringUtils.hasText(comparator)) {
@@ -65,17 +69,21 @@ public abstract class AbstractRemoteFileInboundChannelAdapterParser extends Abst
 		}
 		IntegrationNamespaceUtils.setReferenceIfAttributeDefined(messageSourceBuilder, element, "local-filter");
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(messageSourceBuilder, element, "local-directory");
-		IntegrationNamespaceUtils.setValueIfAttributeDefined(messageSourceBuilder, element, "auto-create-local-directory");
+		IntegrationNamespaceUtils.setValueIfAttributeDefined(messageSourceBuilder, element,
+				"auto-create-local-directory");
 		String localFileGeneratorExpression = element.getAttribute("local-filename-generator-expression");
 		if (StringUtils.hasText(localFileGeneratorExpression)) {
-			BeanDefinitionBuilder localFileGeneratorExpressionBuilder = BeanDefinitionBuilder.genericBeanDefinition(ExpressionFactoryBean.class);
+			BeanDefinitionBuilder localFileGeneratorExpressionBuilder =
+					BeanDefinitionBuilder.genericBeanDefinition(ExpressionFactoryBean.class);
 			localFileGeneratorExpressionBuilder.addConstructorArgValue(localFileGeneratorExpression);
-			synchronizerBuilder.addPropertyValue("localFilenameGeneratorExpression", localFileGeneratorExpressionBuilder.getBeanDefinition());
+			synchronizerBuilder.addPropertyValue("localFilenameGeneratorExpression",
+					localFileGeneratorExpressionBuilder.getBeanDefinition());
 		}
 		return messageSourceBuilder.getBeanDefinition();
 	}
 
-	private void configureFilter(BeanDefinitionBuilder synchronizerBuilder, Element element, ParserContext parserContext) {
+	private void configureFilter(BeanDefinitionBuilder synchronizerBuilder, Element element,
+	                             ParserContext parserContext) {
 		String filter = element.getAttribute("filter");
 		String fileNamePattern = element.getAttribute("filename-pattern");
 		String fileNameRegex = element.getAttribute("filename-regex");

spring-integration-file/src/main/java/org/springframework/integration/file/config/AbstractRemoteFileOutboundGatewayParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -58,7 +58,9 @@ public abstract class AbstractRemoteFileOutboundGatewayParser extends AbstractCo
 		}
 		else {
 			builder.addConstructorArgValue(element.getAttribute("command"));
-			builder.addConstructorArgValue(element.getAttribute(EXPRESSION_ATTRIBUTE));
+			if (element.hasAttribute(EXPRESSION_ATTRIBUTE)) {
+				builder.addConstructorArgValue(element.getAttribute(EXPRESSION_ATTRIBUTE));
+			}
 		}
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "command-options", "options");
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "reply-timeout", "sendTimeout");

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -47,7 +47,6 @@ import org.springframework.integration.file.remote.session.SessionFactory;
 import org.springframework.integration.file.support.FileExistsMode;
 import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
 import org.springframework.integration.handler.ExpressionEvaluatingMessageProcessor;
-import org.springframework.integration.support.AbstractIntegrationMessageBuilder;
 import org.springframework.integration.support.PartialSuccessException;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHandlingException;
@@ -65,7 +64,7 @@ import org.springframework.util.StringUtils;
  */
 public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReplyProducingMessageHandler {
 
-	private final RemoteFileTemplate<F> remoteFileTemplate;
+	protected final RemoteFileTemplate<F> remoteFileTemplate;
 
 	protected final Command command;
 
@@ -512,7 +511,7 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private Object doLs(Message<?> requestMessage) {
 		String dir = this.fileNameProcessor.processMessage(requestMessage);
-		if (!dir.endsWith(this.remoteFileTemplate.getRemoteFileSeparator())) {
+		if (dir != null && !dir.endsWith(this.remoteFileTemplate.getRemoteFileSeparator())) {
 			dir += this.remoteFileTemplate.getRemoteFileSeparator();
 		}
 		final String fullDir = dir;
@@ -529,9 +528,9 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 	}
 
 	private Object doGet(final Message<?> requestMessage) {
-		final String remoteFilePath =  this.fileNameProcessor.processMessage(requestMessage);
-		final String remoteFilename = this.getRemoteFilename(remoteFilePath);
-		final String remoteDir = this.getRemoteDirectory(remoteFilePath, remoteFilename);
+		final String remoteFilePath = this.fileNameProcessor.processMessage(requestMessage);
+		final String remoteFilename = getRemoteFilename(remoteFilePath);
+		final String remoteDir = getRemoteDirectory(remoteFilePath, remoteFilename);
 		Session<F> session = null;
 		Object payload;
 		if (this.options.contains(Option.STREAM)) {
@@ -550,30 +549,27 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 				@Override
 				public File doInSession(Session<F> session) throws IOException {
-					return AbstractRemoteFileOutboundGateway.this.get(requestMessage, session, remoteDir, remoteFilePath,
-							remoteFilename, true);
+					return get(requestMessage, session, remoteDir, remoteFilePath, remoteFilename, true);
 
 				}
 			});
 		}
-		AbstractIntegrationMessageBuilder<Object> builder = this.getMessageBuilderFactory().withPayload(payload)
-			.setHeader(FileHeaders.REMOTE_DIRECTORY, remoteDir)
-			.setHeader(FileHeaders.REMOTE_FILE, remoteFilename);
-		if (session != null) {
-			builder.setHeader(FileHeaders.REMOTE_SESSION, session);
-		}
-		return builder.build();
+		return getMessageBuilderFactory().withPayload(payload)
+				.setHeader(FileHeaders.REMOTE_DIRECTORY, remoteDir)
+				.setHeader(FileHeaders.REMOTE_FILE, remoteFilename)
+				.setHeader(FileHeaders.REMOTE_SESSION, session)
+				.build();
 	}
 
 	private Object doMget(final Message<?> requestMessage) {
-		final String remoteFilePath =  this.fileNameProcessor.processMessage(requestMessage);
-		final String remoteFilename = this.getRemoteFilename(remoteFilePath);
-		final String remoteDir = this.getRemoteDirectory(remoteFilePath, remoteFilename);
+		final String remoteFilePath = this.fileNameProcessor.processMessage(requestMessage);
+		final String remoteFilename = getRemoteFilename(remoteFilePath);
+		final String remoteDir = getRemoteDirectory(remoteFilePath, remoteFilename);
 		List<File> payload = this.remoteFileTemplate.execute(new SessionCallback<F, List<File>>() {
 
 			@Override
 			public List<File> doInSession(Session<F> session) throws IOException {
-				return AbstractRemoteFileOutboundGateway.this.mGet(requestMessage, session, remoteDir, remoteFilename);
+				return mGet(requestMessage, session, remoteDir, remoteFilename);
 			}
 		});
 		return this.getMessageBuilderFactory().withPayload(payload)
@@ -583,10 +579,12 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 	}
 
 	private Object doRm(Message<?> requestMessage) {
-		final String remoteFilePath =  this.fileNameProcessor.processMessage(requestMessage);
-		String remoteFilename = this.getRemoteFilename(remoteFilePath);
-		String remoteDir = this.getRemoteDirectory(remoteFilePath, remoteFilename);
+		final String remoteFilePath = this.fileNameProcessor.processMessage(requestMessage);
+		String remoteFilename = getRemoteFilename(remoteFilePath);
+		String remoteDir = getRemoteDirectory(remoteFilePath, remoteFilename);
+
 		boolean payload = this.remoteFileTemplate.remove(remoteFilePath);
+
 		return this.getMessageBuilderFactory().withPayload(payload)
 			.setHeader(FileHeaders.REMOTE_DIRECTORY, remoteDir)
 			.setHeader(FileHeaders.REMOTE_FILE, remoteFilename)
@@ -595,8 +593,8 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private Object doMv(Message<?> requestMessage) {
 		String remoteFilePath =  this.fileNameProcessor.processMessage(requestMessage);
-		String remoteFilename = this.getRemoteFilename(remoteFilePath);
-		String remoteDir = this.getRemoteDirectory(remoteFilePath, remoteFilename);
+		String remoteFilename = getRemoteFilename(remoteFilePath);
+		String remoteDir = getRemoteDirectory(remoteFilePath, remoteFilename);
 		String remoteFileNewPath = this.renameProcessor.processMessage(requestMessage);
 		Assert.hasLength(remoteFileNewPath, "New filename cannot be empty");
 
@@ -635,8 +633,7 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 			return this.doPut(requestMessage);
 		}
 		else {
-			List<String> replies = this.putLocalDirectory(requestMessage, file, null);
-			return replies;
+			return putLocalDirectory(requestMessage, file, null);
 		}
 	}
 
@@ -717,7 +714,9 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private List<F> listFilesInRemoteDir(Session<F> session, String directory, String subDirectory) throws IOException {
 		List<F> lsFiles = new ArrayList<F>();
-		F[] files = session.list(directory + subDirectory);
+		String remoteDirectory = buildRemotePath(directory, subDirectory);
+
+		F[] files = session.list(remoteDirectory);
 		boolean recursion = this.options.contains(Option.RECURSIVE);
 		if (!ObjectUtils.isEmpty(files)) {
 			Collection<F> filteredFiles = this.filterFiles(files);
@@ -742,6 +741,17 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 		return lsFiles;
 	}
 
+	private String buildRemotePath(String parent, String child) {
+		String remotePath = null;
+		if (parent != null) {
+			remotePath = (parent + child);
+		}
+		else if (StringUtils.hasText(child)) {
+			remotePath = "." + this.remoteFileTemplate.getRemoteFileSeparator() + child;
+		}
+		return remotePath;
+	}
+
 	protected final List<F> filterFiles(F[] files) {
 		return (this.filter != null) ? this.filter.filterFiles(files) : Arrays.asList(files);
 	}
@@ -784,8 +794,8 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 	 * @return The file.
 	 * @throws IOException Any IOException.
 	 */
-	protected File get(Message<?> message, Session<F> session, String remoteDir, String remoteFilePath, String remoteFilename, boolean lsFirst)
-			throws IOException {
+	protected File get(Message<?> message, Session<F> session, String remoteDir, String remoteFilePath,
+	                   String remoteFilename, boolean lsFirst) throws IOException {
 		F[] files = null;
 		if (lsFirst) {
 			files = session.list(remoteFilePath);
@@ -796,7 +806,8 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 				throw new MessagingException(remoteFilePath + " is not a file");
 			}
 		}
-		File localFile = new File(this.generateLocalDirectory(message, remoteDir), this.generateLocalFileName(message, remoteFilename));
+		File localFile =
+				new File(generateLocalDirectory(message, remoteDir), generateLocalFileName(message, remoteFilename));
 		FileExistsMode fileExistsMode = this.fileExistsMode;
 		boolean appending = FileExistsMode.APPEND.equals(fileExistsMode);
 		boolean replacing = FileExistsMode.REPLACE.equals(fileExistsMode);
@@ -874,37 +885,40 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private List<File> mGetWithoutRecursion(Message<?> message, Session<F> session, String remoteDirectory,
 			String remoteFilename) throws IOException {
-		String path = this.generateFullPath(remoteDirectory, remoteFilename);
-		String[] fileNames = session.listNames(path);
-		if (fileNames == null) {
-			fileNames = new String[0];
-		}
-		if (fileNames.length == 0 && this.options.contains(Option.EXCEPTION_WHEN_EMPTY)) {
-			throw new MessagingException("No files found at " + remoteDirectory
+		List<File> files = new ArrayList<File>();
+		String remotePath = buildRemotePath(remoteDirectory, remoteFilename);
+		@SuppressWarnings("unchecked")
+		List<AbstractFileInfo<F>> remoteFiles = (List<AbstractFileInfo<F>>) ls(session, remotePath);
+		if (remoteFiles.size() == 0 && this.options.contains(Option.EXCEPTION_WHEN_EMPTY)) {
+			throw new MessagingException("No files found at "
+					+ (remoteDirectory != null ? remoteDirectory : "Client Working Directory")
 					+ " with pattern " + remoteFilename);
 		}
-		List<File> files = new ArrayList<File>();
-		String remoteFileSeparator = this.remoteFileTemplate.getRemoteFileSeparator();
 		try {
-			for (String fileName : fileNames) {
-				File file;
-				if (fileName.contains(remoteFileSeparator) &&
-						fileName.startsWith(remoteDirectory)) { // the server returned the full path
-					file = this.get(message, session, remoteDirectory, fileName,
-							fileName.substring(fileName.lastIndexOf(remoteFileSeparator)), false);
-				}
-				else {
-					file = this.get(message, session, remoteDirectory,
-							this.generateFullPath(remoteDirectory, fileName), fileName, false);
+			for (AbstractFileInfo<F> lsEntry : remoteFiles) {
+				if (lsEntry.isDirectory()) {
+					continue;
 				}
+				String fullFileName = remoteDirectory != null
+						? remoteDirectory + getFilename(lsEntry)
+						: getFilename(lsEntry);
+				/*
+				 * With recursion, the filename might contain subdirectory information
+				 * normalize each file separately.
+				 */
+				String fileName = this.getRemoteFilename(fullFileName);
+				String actualRemoteDirectory = this.getRemoteDirectory(fullFileName, fileName);
+				File file = this.get(message, session, actualRemoteDirectory,
+						fullFileName, fileName, false);
 				files.add(file);
 			}
 		}
 		catch (Exception e) {
 			if (files.size() > 0) {
 				throw new PartialSuccessException(message,
-						"Partially successful 'mget' operation on " + remoteDirectory, e, files,
-						Arrays.asList(fileNames));
+						"Partially successful recursive 'mget' operation on "
+								+ (remoteDirectory != null ? remoteDirectory : "Client Working Directory"),
+						e, files, remoteFiles);
 			}
 			else if (e instanceof MessagingException) {
 				throw (MessagingException) e;
@@ -920,14 +934,17 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 			String remoteFilename) throws IOException {
 		List<File> files = new ArrayList<File>();
 		@SuppressWarnings("unchecked")
-		List<AbstractFileInfo<F>> fileNames = (List<AbstractFileInfo<F>>) this.ls(session, remoteDirectory);
+		List<AbstractFileInfo<F>> fileNames = (List<AbstractFileInfo<F>>) ls(session, remoteDirectory);
 		if (fileNames.size() == 0 && this.options.contains(Option.EXCEPTION_WHEN_EMPTY)) {
-			throw new MessagingException("No files found at " + remoteDirectory
+			throw new MessagingException("No files found at "
+					+ (remoteDirectory != null ? remoteDirectory : "Client Working Directory")
 					+ " with pattern " + remoteFilename);
 		}
 		try {
 			for (AbstractFileInfo<F> lsEntry : fileNames) {
-				String fullFileName = remoteDirectory + this.getFilename(lsEntry);
+				String fullFileName = remoteDirectory != null
+						? remoteDirectory + getFilename(lsEntry)
+						: getFilename(lsEntry);
 				/*
 				 * With recursion, the filename might contain subdirectory information
 				 * normalize each file separately.
@@ -942,7 +959,9 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 		catch (Exception e) {
 			if (files.size() > 0) {
 				throw new PartialSuccessException(message,
-						"Partially successful recursive 'mget' operation on " + remoteDirectory, e, files, fileNames);
+						"Partially successful recursive 'mget' operation on "
+								+ (remoteDirectory != null ? remoteDirectory : "Client Working Directory"),
+						e, files, fileNames);
 			}
 			else if (e instanceof MessagingException) {
 				throw (MessagingException) e;
@@ -957,45 +976,30 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 	private String getRemoteDirectory(String remoteFilePath, String remoteFilename) {
 		String remoteDir = remoteFilePath.substring(0, remoteFilePath.lastIndexOf(remoteFilename));
 		if (remoteDir.length() == 0) {
-			remoteDir = this.remoteFileTemplate.getRemoteFileSeparator();
+			return null;
 		}
 		return remoteDir;
 	}
 
-	private String generateFullPath(String remoteDirectory, String remoteFilename) {
-		String path;
-		String remoteFileSeparator = this.remoteFileTemplate.getRemoteFileSeparator();
-		if (remoteFileSeparator.equals(remoteDirectory)) {
-			path = remoteFilename;
-		}
-		else if (remoteDirectory.endsWith(remoteFileSeparator)) {
-			path = remoteDirectory + remoteFilename;
-		}
-		else {
-			path = remoteDirectory + remoteFileSeparator + remoteFilename;
-		}
-		return path;
-	}
-
 	/**
 	 * @param remoteFilePath The remote file path.
 	 * @return The remote file name.
 	 */
 	protected String getRemoteFilename(String remoteFilePath) {
-		String remoteFileName;
 		int index = remoteFilePath.lastIndexOf(this.remoteFileTemplate.getRemoteFileSeparator());
 		if (index < 0) {
-			remoteFileName = remoteFilePath;
+			return remoteFilePath;
 		}
 		else {
-			remoteFileName = remoteFilePath.substring(index + 1);
+			return remoteFilePath.substring(index + 1);
 		}
-		return remoteFileName;
 	}
 
 	private File generateLocalDirectory(Message<?> message, String remoteDirectory) {
-		EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(this.getBeanFactory());
-		evaluationContext.setVariable("remoteDirectory", remoteDirectory);
+		EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(getBeanFactory());
+		if (remoteDirectory != null) {
+			evaluationContext.setVariable("remoteDirectory", remoteDirectory);
+		}
 		//TODO see org.springframework.integration.context.CustomConversionServiceFactoryBean
 //		File localDir = this.localDirectoryExpression.getValue(evaluationContext, message, File.class);
 		String localDirPath = this.localDirectoryExpression.getValue(evaluationContext, message, String.class);
@@ -1008,7 +1012,7 @@ public abstract class AbstractRemoteFileOutboundGateway<F> extends AbstractReply
 
 	private String generateLocalFileName(Message<?> message, String remoteFileName){
 		if (this.localFilenameGeneratorExpression != null){
-			EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(this.getBeanFactory());
+			EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(getBeanFactory());
 			evaluationContext.setVariable("remoteFileName", remoteFileName);
 			return this.localFilenameGeneratorExpression.getValue(evaluationContext, message, String.class);
 		}

spring-integration-file/src/main/java/org/springframework/integration/file/remote/synchronizer/AbstractInboundFileSynchronizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -200,6 +200,14 @@ public abstract class AbstractInboundFileSynchronizer<F>
 		if (this.evaluationContext == null) {
 			this.evaluationContext = ExpressionUtils.createStandardEvaluationContext(this.beanFactory);
 		}
+		doInit();
+	}
+
+	/**
+	 * Subclasses can override to perform initialization - called from
+	 * {@link InitializingBean#afterPropertiesSet()}.
+	 */
+	protected void doInit() {
 	}
 
 	protected final List<F> filterFiles(F[] files) {
@@ -271,7 +279,9 @@ public abstract class AbstractInboundFileSynchronizer<F>
 			Session<F> session) throws IOException {
 		String remoteFileName = this.getFilename(remoteFile);
 		String localFileName = this.generateLocalFileName(remoteFileName);
-		String remoteFilePath = remoteDirectoryPath + remoteFileSeparator + remoteFileName;
+		String remoteFilePath = remoteDirectoryPath != null
+				? (remoteDirectoryPath + remoteFileSeparator + remoteFileName)
+				: remoteFileName;
 		if (!this.isFile(remoteFile)) {
 			if (logger.isDebugEnabled()) {
 				logger.debug("cannot copy, not a file: " + remoteFilePath);

spring-integration-file/src/test/java/org/springframework/integration/file/remote/gateway/RemoteFileOutboundGatewayTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -23,6 +23,7 @@ import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
@@ -188,8 +189,10 @@ public class RemoteFileOutboundGatewayTests {
 			}
 
 			@Override
-			public String[] listNames(String path) throws IOException {
-				return new String[] { path1, path2 };
+			public TestLsEntry[] list(String path) throws IOException {
+				return new TestLsEntry[] {
+						new TestLsEntry(path1.replaceFirst("testremote/", ""), 123, false, false, 1234, "-r--r--r--"),
+						new TestLsEntry(path2.replaceFirst("testremote/", ""), 123, false, false, 1234, "-r--r--r--")};
 			}
 
 		});
@@ -220,8 +223,8 @@ public class RemoteFileOutboundGatewayTests {
 			}
 
 			@Override
-			public String[] listNames(String path) throws IOException {
-				return new String[]{"f1"};
+			public TestLsEntry[] list(String path) throws IOException {
+				return new TestLsEntry[]{new TestLsEntry("f1", 123, false, false, 1234, "-r--r--r--")};
 			}
 
 		});
@@ -621,10 +624,8 @@ public class RemoteFileOutboundGatewayTests {
 		assertEquals(outFile, out.getPayload());
 		assertTrue(outFile.exists());
 		outFile.delete();
-		assertEquals("/",
-				out.getHeaders().get(FileHeaders.REMOTE_DIRECTORY));
-		assertEquals("f1",
-				out.getHeaders().get(FileHeaders.REMOTE_FILE));
+		assertNull(out.getHeaders().get(FileHeaders.REMOTE_DIRECTORY));
+		assertEquals("f1", out.getHeaders().get(FileHeaders.REMOTE_FILE));
 	}
 
 	@SuppressWarnings("unchecked")