From 37a566efff0b61d5a1e0e4cb608b14713c2b205a Mon Sep 17 00:00:00 2001
From: Artem Bilan <abilan@pivotal.io>
Date: Thu, 7 Jul 2016 13:05:23 -0400
Subject: [PATCH] INT-4067: Cover empty file case in `FileSplitter`

JIRA: https://jira.spring.io/browse/INT-4067

When `FileSplitter` is configured with `markers = true` and file is empty, an `iterator` for file throws `IOException: Stream closed`,
because we close the `buffer` just after the first `readLine()` attempt, but still return `true` from the first `hasNext()` call
where the `this.sof` and `this.eof` are `true` for markers.

Add logic to mark internal splitter `iterator` as `done` where we don't have content and still in `sof` state.
---
 .../file/splitter/FileSplitter.java           |  3 ++
 .../file/splitter/FileSplitterTests.java      | 28 +++++++++++++++++++
 src/reference/asciidoc/file.adoc              |  3 +-
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/spring-integration-file/src/main/java/org/springframework/integration/file/splitter/FileSplitter.java b/spring-integration-file/src/main/java/org/springframework/integration/file/splitter/FileSplitter.java
index 9bbd49ab0c..031b7375da 100644
--- a/spring-integration-file/src/main/java/org/springframework/integration/file/splitter/FileSplitter.java
+++ b/spring-integration-file/src/main/java/org/springframework/integration/file/splitter/FileSplitter.java
@@ -216,6 +216,9 @@ public class FileSplitter extends AbstractMessageSplitter {
 					if (!ready) {
 						if (this.markers) {
 							this.eof = true;
+							if (this.sof) {
+								this.done = true;
+							}
 						}
 						bufferedReader.close();
 					}
diff --git a/spring-integration-file/src/test/java/org/springframework/integration/file/splitter/FileSplitterTests.java b/spring-integration-file/src/test/java/org/springframework/integration/file/splitter/FileSplitterTests.java
index b5e8274d9a..d7be4288da 100644
--- a/spring-integration-file/src/test/java/org/springframework/integration/file/splitter/FileSplitterTests.java
+++ b/spring-integration-file/src/test/java/org/springframework/integration/file/splitter/FileSplitterTests.java
@@ -207,6 +207,34 @@ public class FileSplitterTests {
 		assertEquals(2, fileMarker.getLineCount());
 	}
 
+	@Test
+	public void testMarkersEmptyFile() throws IOException {
+		QueueChannel outputChannel = new QueueChannel();
+		FileSplitter splitter = new FileSplitter(true, true);
+		splitter.setOutputChannel(outputChannel);
+		File file = File.createTempFile("empty", ".txt");
+		splitter.handleMessage(new GenericMessage<File>(file));
+		Message<?> received = outputChannel.receive(0);
+		assertNotNull(received);
+		assertNull(received.getHeaders().get(IntegrationMessageHeaderAccessor.SEQUENCE_SIZE));
+		assertEquals("START", received.getHeaders().get(FileHeaders.MARKER));
+		assertThat(received.getPayload(), instanceOf(FileSplitter.FileMarker.class));
+		FileMarker fileMarker = (FileSplitter.FileMarker) received.getPayload();
+		assertEquals(FileMarker.Mark.START, fileMarker.getMark());
+		assertEquals(file.getAbsolutePath(), fileMarker.getFilePath());
+		assertEquals(0, fileMarker.getLineCount());
+
+		received = outputChannel.receive(0);
+		assertNotNull(received);
+
+		assertEquals("END", received.getHeaders().get(FileHeaders.MARKER));
+		assertThat(received.getPayload(), instanceOf(FileSplitter.FileMarker.class));
+		fileMarker = (FileSplitter.FileMarker) received.getPayload();
+		assertEquals(FileMarker.Mark.END, fileMarker.getMark());
+		assertEquals(file.getAbsolutePath(), fileMarker.getFilePath());
+		assertEquals(0, fileMarker.getLineCount());
+	}
+
 	@Test
 	public void testMarkersJson() throws Exception {
 		JsonObjectMapper<?, ?> objectMapper = JsonObjectMapperProvider.newInstance();
diff --git a/src/reference/asciidoc/file.adoc b/src/reference/asciidoc/file.adoc
index 3e98736fa2..21b2a39e22 100644
--- a/src/reference/asciidoc/file.adoc
+++ b/src/reference/asciidoc/file.adoc
@@ -751,7 +751,8 @@ Markers are messages with `FileSplitter.FileMarker` payloads (with `START` and `
 Markers might be used when sequentially processing files in a downstream flow where some lines are filtered.
 They enable the downstream processing to know when a file has been completely processed.
 In addition, a header `file_marker` containing `START` or `END` are added to these messages.
-The 'END' marker includes a line count.
+The `END` marker includes a line count.
+If the file is empty, only `START` and `END` markers are emitted with `0` as the `lineCount`.
 Default: `false`.
 When `true`, `apply-sequence` is `false` by default.