From d8e4818c5e35991e9eafe270ebbe4a75930c0d2e Mon Sep 17 00:00:00 2001
From: Gavin Gray <gatrot@gmail.com>
Date: Fri, 7 Feb 2014 12:46:16 -0500
Subject: [PATCH] INT-3290 Fix TCP Deserializer for 0 Length Message

ByteArraySingleTerminatorSerializer does not support multiple
subsequent terminators (zero length messages).

JIRA: https://jira.springsource.org/browse/INT-3290

* Add unit test to verify bug.
* Fix bug.

Polishing:

* Remove test for `n >= 0`; n cannot be < 0 here
* Move test case to `DeserializationTests`
---
 .../ByteArraySingleTerminatorSerializer.java  |  7 +++---
 .../tcp/serializer/DeserializationTests.java  | 22 ++++++++++++++++++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/serializer/ByteArraySingleTerminatorSerializer.java b/spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/serializer/ByteArraySingleTerminatorSerializer.java
index de20688a80..39bee41df3 100644
--- a/spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/serializer/ByteArraySingleTerminatorSerializer.java
+++ b/spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/serializer/ByteArraySingleTerminatorSerializer.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -42,6 +42,7 @@ public class ByteArraySingleTerminatorSerializer extends AbstractByteArraySerial
 	 * is closed immediately after the terminator (i.e. no data is in the process of
 	 * being read).
 	 */
+	@Override
 	public byte[] deserialize(InputStream inputStream) throws IOException {
 		byte[] buffer = new byte[this.maxMessageSize];
 		int n = 0;
@@ -51,12 +52,11 @@ public class ByteArraySingleTerminatorSerializer extends AbstractByteArraySerial
 		}
 		while (true) {
 			bite = inputStream.read();
-//			logger.debug("Read:" + (char) bite);
 			if (bite < 0 && n == 0) {
 				throw new SoftEndOfStreamException("Stream closed between payloads");
 			}
 			checkClosure(bite);
-			if (n > 0 && bite == terminator) {
+			if (bite == terminator) {
 				break;
 			}
 			buffer[n++] = (byte) bite;
@@ -73,6 +73,7 @@ public class ByteArraySingleTerminatorSerializer extends AbstractByteArraySerial
 	/**
 	 * Writes the byte[] to the stream and appends the terminator.
 	 */
+	@Override
 	public void serialize(byte[] bytes, OutputStream outputStream) throws IOException {
 		outputStream.write(bytes);
 		outputStream.write(terminator);
diff --git a/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/serializer/DeserializationTests.java b/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/serializer/DeserializationTests.java
index edcbfd4af9..a713cc9534 100644
--- a/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/serializer/DeserializationTests.java
+++ b/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/serializer/DeserializationTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -19,6 +19,7 @@ package org.springframework.integration.ip.tcp.serializer;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
@@ -34,6 +35,7 @@ import org.springframework.integration.test.util.SocketUtils;
 
 /**
  * @author Gary Russell
+ * @author Gavin Gray
  * @since 2.0
  */
 public class DeserializationTests {
@@ -240,4 +242,22 @@ public class DeserializationTests {
 		latch.countDown();
 	}
 
+    @Test
+    public void canDeserializeMultipleSubsequentTerminators() throws IOException {
+        byte terminator = (byte) '\n';
+        ByteArraySingleTerminatorSerializer serializer = new ByteArraySingleTerminatorSerializer(terminator);
+        ByteArrayInputStream inputStream = new ByteArrayInputStream("s\n\n".getBytes());
+
+        try {
+            byte[] bytes = serializer.deserialize(inputStream);
+            assertEquals(1, bytes.length);
+            assertEquals("s".getBytes()[0], bytes[0]);
+            bytes = serializer.deserialize(inputStream);
+            assertEquals(0, bytes.length);
+        }
+        finally {
+            inputStream.close();
+        }
+    }
+
 }