From 696ed10aa255fb22126e056e83ed90392191f95c Mon Sep 17 00:00:00 2001
From: Gary Russell <grussell@pivotal.io>
Date: Tue, 12 May 2015 18:24:39 +0100
Subject: [PATCH] INT-3715: Fix Thread Safety in SyslogTransformer

JIRA: https://jira.spring.io/browse/INT-3715

`SimpleDateFormat` is not thread-safe.
---
 .../transformer/SyslogToMapTransformer.java         | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/transformer/SyslogToMapTransformer.java b/spring-integration-core/src/main/java/org/springframework/integration/transformer/SyslogToMapTransformer.java
index 719e415e6c..726e732939 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/transformer/SyslogToMapTransformer.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/transformer/SyslogToMapTransformer.java
@@ -22,6 +22,8 @@ import java.util.Calendar;
 import java.util.Date;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -40,6 +42,8 @@ import org.springframework.util.Assert;
  */
 public class SyslogToMapTransformer extends AbstractPayloadTransformer<Object, Map<String, ?>> {
 
+	private static final BlockingQueue<SimpleDateFormat> dateFormats = new LinkedBlockingQueue<SimpleDateFormat>();
+
 	public static final String FACILITY = "FACILITY";
 
 	public static final String SEVERITY = "SEVERITY";
@@ -56,8 +60,6 @@ public class SyslogToMapTransformer extends AbstractPayloadTransformer<Object, M
 
 	private final Pattern pattern = Pattern.compile("<([^>]+)>(.{15}) ([^ ]+) (?:([^:]+): )?(.*)", Pattern.DOTALL);
 
-	private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss");
-
 	@Override
 	protected Map<String, ?> transformPayload(Object payload) throws Exception {
 		boolean isByteArray = payload instanceof byte[];
@@ -86,6 +88,10 @@ public class SyslogToMapTransformer extends AbstractPayloadTransformer<Object, M
 	private Map<String, ?> transform(String payload) {
 		Map<String, Object> map = new LinkedHashMap<String, Object>();
 		Matcher matcher = pattern.matcher(payload);
+		SimpleDateFormat dateFormat = dateFormats.poll();
+		if (dateFormat == null) {
+			dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss");
+		}
 		if (matcher.matches()) {
 			try {
 				String facilityString = matcher.group(1);
@@ -97,7 +103,8 @@ public class SyslogToMapTransformer extends AbstractPayloadTransformer<Object, M
 				String timestamp = matcher.group(2);
 				Date date;
 				try {
-					date = this.dateFormat.parse(timestamp);
+					date = dateFormat.parse(timestamp);
+					dateFormats.offer(dateFormat);
 					Calendar calendar = Calendar.getInstance();
 					int year = calendar.get(Calendar.YEAR);
 					int month = calendar.get(Calendar.MONTH);