INT-832: Add File Relative Path to Message Headers

JIRA: https://jira.spring.io/browse/INT-832

When we scan directory recursively for files (e.g. `WatchServiceDirectoryScanner`), it can be useful to get access to the relative path from the `Message`, e.g. on the `FileWritingMessageHandler` side to restore the original structure

* Add a `FileHeaders.FILENAME` into the outbound `Message` from the `FileReadingMessageSource`
* The result of that header is like a removal of leading `this.directory.getAbsolutePath()` in the target `File.getAbsolutePath()`.
In case of not recursion we get just only regular file name.

* Introduce `FileHeaders.RELATIVE_PATH`
* Populated `FileHeaders.RELATIVE_PATH`, `FileHeaders.FILENAME`, `FileHeaders.ORIGINAL_FILE` in the `FileReadingMessageSource`
* File `FileTailingMessageProducerSupport` to populate `FileHeaders` properly
* Introduce ctor for the `LastModifiedFileListFilter` for better Java configuration experience
* Add docs for changes

Doc Polishing

spring-integration-file/src/main/java/org/springframework/integration/file/FileHeaders.java

@@ -22,6 +22,7 @@ package org.springframework.integration.file;
  *
  * @author Mark Fisher
  * @author Gary Russell
+ * @author Artem Bilan
  */
 public abstract class FileHeaders {
 
@@ -29,6 +30,8 @@ public abstract class FileHeaders {
 
 	public static final String FILENAME = PREFIX + "name";
 
+	public static final String RELATIVE_PATH = PREFIX + "relativePath";
+
 	public static final String ORIGINAL_FILE = PREFIX + "originalFile";
 
 	public static final String REMOTE_DIRECTORY = PREFIX + "remoteDirectory";

spring-integration-file/src/main/java/org/springframework/integration/file/FileReadingMessageSource.java

@@ -39,6 +39,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.PriorityBlockingQueue;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.regex.Matcher;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -361,7 +362,13 @@ public class FileReadingMessageSource extends IntegrationObjectSupport implement
 		}
 
 		if (file != null) {
-			message = this.getMessageBuilderFactory().withPayload(file).build();
+			message = getMessageBuilderFactory().withPayload(file)
+					.setHeader(FileHeaders.RELATIVE_PATH, file.getAbsolutePath()
+							.replaceFirst(Matcher.quoteReplacement(this.directory.getAbsolutePath() + File.separator),
+									""))
+					.setHeader(FileHeaders.FILENAME, file.getName())
+					.setHeader(FileHeaders.ORIGINAL_FILE, file)
+					.build();
 			if (logger.isInfoEnabled()) {
 				logger.info("Created message: [" + message + "]");
 			}

spring-integration-file/src/main/java/org/springframework/integration/file/filters/LastModifiedFileListFilter.java

@@ -29,6 +29,7 @@ import java.util.concurrent.TimeUnit;
  * The resolution is done in seconds.
  *
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 4.2
  *
  */
@@ -42,6 +43,19 @@ public class LastModifiedFileListFilter implements FileListFilter<File> {
 		return this.age;
 	}
 
+	public LastModifiedFileListFilter() {
+	}
+
+	/**
+	 * Construct a {@link LastModifiedFileListFilter} instance with provided {@link #age}.
+	 * Defaults to 60 seconds.
+	 * @param age the age in seconds.
+	 * @since 5.0
+	 */
+	public LastModifiedFileListFilter(long age) {
+		this.age = age;
+	}
+
 	/**
 	 * Set the age that files have to be before being passed by this filter.
 	 * If {@link File#lastModified()} plus age is greater than the current time, the file

spring-integration-file/src/main/java/org/springframework/integration/file/tail/FileTailingMessageProducerSupport.java

@@ -32,6 +32,7 @@ import org.springframework.util.Assert;
  * Base class for file tailing inbound adapters.
  *
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 3.0
  *
  */
@@ -101,7 +102,8 @@ public abstract class FileTailingMessageProducerSupport extends MessageProducerS
 
 	protected void send(String line) {
 		Message<?> message = this.getMessageBuilderFactory().withPayload(line)
-				.setHeader(FileHeaders.FILENAME, this.file.getAbsolutePath())
+				.setHeader(FileHeaders.FILENAME, this.file.getName())
+				.setHeader(FileHeaders.ORIGINAL_FILE, this.file)
 				.build();
 		super.sendMessage(message);
 	}

spring-integration-file/src/test/java/org/springframework/integration/file/FileReadingMessageSourceIntegrationTests.java

@@ -134,7 +134,12 @@ public class FileReadingMessageSourceIntegrationTests {
 	public void inputDirExhausted() throws Exception {
 		assertNotNull(pollableFileSource.receive());
 		assertNotNull(pollableFileSource.receive());
-		assertNotNull(pollableFileSource.receive());
+		Message<File> receive = pollableFileSource.receive();
+		assertNotNull(receive);
+		File payload = receive.getPayload();
+		assertEquals(payload, receive.getHeaders().get(FileHeaders.ORIGINAL_FILE));
+		assertEquals(payload.getName(), receive.getHeaders().get(FileHeaders.FILENAME));
+		assertEquals(payload.getName(), receive.getHeaders().get(FileHeaders.RELATIVE_PATH));
 		assertNull(pollableFileSource.receive());
 	}
 

spring-integration-file/src/test/java/org/springframework/integration/file/FileReadingMessageSourceTests.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.
@@ -44,6 +44,7 @@ import org.springframework.messaging.Message;
  * @author Iwein Fuld
  * @author Mark Fisher
  * @author Artem Bilan
+ * @author Gary Russell
  */
 @RunWith(MockitoJUnitRunner.class)
 public class FileReadingMessageSourceTests {
@@ -66,6 +67,8 @@ public class FileReadingMessageSourceTests {
 		when(inputDirectoryMock.isDirectory()).thenReturn(true);
 		when(inputDirectoryMock.exists()).thenReturn(true);
 		when(inputDirectoryMock.canRead()).thenReturn(true);
+		when(inputDirectoryMock.getAbsolutePath()).thenReturn("foo/bar");
+		when(fileMock.getAbsolutePath()).thenReturn("foo/bar/fileMock");
 		when(locker.lock(isA(File.class))).thenReturn(true);
 	}
 
@@ -80,13 +83,13 @@ public class FileReadingMessageSourceTests {
 
 	@Test
 	public void straightProcess() throws Exception {
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock});
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock });
 		assertThat(source.receive().getPayload(), is(fileMock));
 	}
 
 	@Test
 	public void requeueOnFailure() throws Exception {
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock});
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock });
 		Message<File> received = source.receive();
 		assertNotNull(received);
 		source.onFailure(received);
@@ -97,7 +100,8 @@ public class FileReadingMessageSourceTests {
 	@Test
 	public void scanEachPoll() throws Exception {
 		File anotherFileMock = mock(File.class);
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock, anotherFileMock});
+		when(anotherFileMock.getAbsolutePath()).thenReturn("foo/bar/anotherFileMock");
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock, anotherFileMock });
 		source.setScanEachPoll(true);
 		assertNotNull(source.receive());
 		assertNotNull(source.receive());
@@ -107,7 +111,7 @@ public class FileReadingMessageSourceTests {
 
 	@Test
 	public void noDuplication() throws Exception {
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock});
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock });
 		Message<File> received = source.receive();
 		assertNotNull(received);
 		assertEquals(fileMock, received.getPayload());
@@ -122,7 +126,7 @@ public class FileReadingMessageSourceTests {
 
 	@Test
 	public void lockIsAcquired() throws IOException {
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock});
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock });
 		Message<File> received = source.receive();
 		assertNotNull(received);
 		assertEquals(fileMock, received.getPayload());
@@ -131,7 +135,7 @@ public class FileReadingMessageSourceTests {
 
 	@Test
 	public void lockedFilesAreIgnored() throws IOException {
-		when(inputDirectoryMock.listFiles()).thenReturn(new File[]{fileMock});
+		when(inputDirectoryMock.listFiles()).thenReturn(new File[] { fileMock });
 		when(locker.lock(fileMock)).thenReturn(false);
 		Message<File> received = source.receive();
 		assertNull(received);
@@ -141,8 +145,11 @@ public class FileReadingMessageSourceTests {
 	@Test
 	public void orderedReception() throws Exception {
 		File file1 = mock(File.class);
+		when(file1.getAbsolutePath()).thenReturn("foo/bar/file1");
 		File file2 = mock(File.class);
+		when(file2.getAbsolutePath()).thenReturn("foo/bar/file2");
 		File file3 = mock(File.class);
+		when(file3.getAbsolutePath()).thenReturn("foo/bar/file3");
 
 		// record the comparator to reverse order the files
 		when(comparator.compare(file1, file2)).thenReturn(1);

spring-integration-file/src/test/java/org/springframework/integration/file/WatchServiceDirectoryScannerTests.java

@@ -17,7 +17,9 @@
 package org.springframework.integration.file;
 
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
@@ -39,6 +41,8 @@ import org.junit.rules.TemporaryFolder;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.integration.file.filters.FileSystemPersistentAcceptOnceFileListFilter;
 import org.springframework.integration.metadata.SimpleMetadataStore;
+import org.springframework.integration.test.util.TestUtils;
+import org.springframework.messaging.Message;
 
 /**
  * @author Gary Russell
@@ -71,7 +75,7 @@ public class WatchServiceDirectoryScannerTests {
 	}
 
 	@Test
-	public void testInitialAndAddMoreThenRemove() throws Exception {
+	public void testWatchServiceDirectoryScanner() throws Exception {
 		FileReadingMessageSource fileReadingMessageSource = new FileReadingMessageSource();
 		fileReadingMessageSource.setDirectory(folder.getRoot());
 		fileReadingMessageSource.setUseWatchService(true);
@@ -188,6 +192,19 @@ public class WatchServiceDirectoryScannerTests {
 
 		assertTrue(removeFileLatch.await(10, TimeUnit.SECONDS));
 
+		File baz3 = File.createTempFile("baz3", ".txt", baz);
+
+		n = 0;
+		Message<File> fileMessage = null;
+		while (n++ < 300 && (fileMessage = fileReadingMessageSource.receive()) == null) {
+			Thread.sleep(100);
+		}
+
+		assertNotNull(fileMessage);
+		assertEquals(baz3, fileMessage.getPayload());
+		assertThat(fileMessage.getHeaders().get(FileHeaders.RELATIVE_PATH, String.class),
+				startsWith(TestUtils.applySystemFileSeparator("foo/baz/")));
+
 		fileReadingMessageSource.stop();
 	}
 

spring-integration-file/src/test/java/org/springframework/integration/file/tail/FileTailingMessageProducerTests.java

@@ -37,12 +37,14 @@ import org.junit.Test;
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.integration.channel.QueueChannel;
+import org.springframework.integration.file.FileHeaders;
 import org.springframework.integration.file.tail.FileTailingMessageProducerSupport.FileTailingEvent;
 import org.springframework.messaging.Message;
 
 /**
  * @author Gary Russell
  * @author Gavin Gray
+ * @author Artem Bilan
  * @since 3.0
  *
  */
@@ -169,6 +171,8 @@ public class FileTailingMessageProducerTests {
 			Message<?> message = outputChannel.receive(10000);
 			assertNotNull("expected a non-null message", message);
 			assertEquals("hello" + i, message.getPayload());
+			assertEquals(file, message.getHeaders().get(FileHeaders.ORIGINAL_FILE));
+			assertEquals(file.getName(), message.getHeaders().get(FileHeaders.FILENAME));
 		}
 	}