INT-3310 Fix Syslog Error on Socket Close

https://jira.springsource.org/browse/INT-3310

Previously, the syslog adapter tried to convert the ErrorMessage
that results from a socket error to a syslog packet, resulting
in a stack trace on stderr.

Test for the ErrorMessage and log at DEBUG.

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/inbound/SyslogReceivingChannelAdapterSupport.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.
@@ -17,9 +17,11 @@ package org.springframework.integration.syslog.inbound;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.integration.Message;
 import org.springframework.integration.MessagingException;
 import org.springframework.integration.endpoint.MessageProducerSupport;
+import org.springframework.integration.message.ErrorMessage;
 import org.springframework.integration.syslog.DefaultMessageConverter;
 import org.springframework.integration.syslog.MessageConverter;
 
@@ -70,7 +72,14 @@ public abstract class SyslogReceivingChannelAdapterSupport extends MessageProduc
 
 	protected void convertAndSend(Message<?> message) {
 		try {
-			this.sendMessage(this.converter.fromSyslog(message));
+			if (message instanceof ErrorMessage) {
+				if (logger.isDebugEnabled()) {
+					logger.debug("Error on syslog socket:" + ((ErrorMessage) message).getPayload().getMessage());
+				}
+			}
+			else {
+				this.sendMessage(this.converter.fromSyslog(message));
+			}
 		}
 		catch (Exception e) {
 			throw new MessagingException(message, e);

spring-integration-syslog/src/test/java/org/springframework/integration/syslog/inbound/SyslogReceivingChannelAdapterTests.java

@@ -19,8 +19,11 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
@@ -31,10 +34,12 @@ import java.util.concurrent.TimeUnit;
 
 import javax.net.SocketFactory;
 
+import org.apache.commons.logging.Log;
 import org.junit.Test;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.integration.Message;
@@ -42,7 +47,7 @@ import org.springframework.integration.channel.QueueChannel;
 import org.springframework.integration.core.PollableChannel;
 import org.springframework.integration.syslog.config.SyslogReceivingChannelAdapterFactoryBean;
 import org.springframework.integration.test.util.SocketUtils;
-
+import org.springframework.integration.test.util.TestUtils;
 /**
  * @author Gary Russell
  * @since 3.0
@@ -95,11 +100,27 @@ public class SyslogReceivingChannelAdapterTests {
 		factory.afterPropertiesSet();
 		factory.start();
 		TcpSyslogReceivingChannelAdapter adapter = (TcpSyslogReceivingChannelAdapter) factory.getObject();
+		Log logger = spy(TestUtils.getPropertyValue(adapter, "logger", Log.class));
+		doReturn(true).when(logger).isDebugEnabled();
+		final CountDownLatch sawLog = new CountDownLatch(1);
+		doAnswer(new Answer<Void>(){
+
+			@Override
+			public Void answer(InvocationOnMock invocation) throws Throwable {
+				if (((String) invocation.getArguments()[0]).contains("Error on syslog socket")) {
+					sawLog.countDown();
+				}
+				invocation.callRealMethod();
+				return null;
+			}
+		}).when(logger).debug(anyString());
+		new DirectFieldAccessor(adapter).setPropertyValue("logger", logger);
 		Thread.sleep(1000);
 		byte[] buf = "<157>JUL 26 22:08:35 WEBERN TESTING[70729]: TEST SYSLOG MESSAGE\n".getBytes("UTF-8");
 		Socket socket = SocketFactory.getDefault().createSocket("localhost", port);
 		socket.getOutputStream().write(buf);
 		socket.close();
+		assertTrue(sawLog.await(10, TimeUnit.SECONDS));
 		Message<?> message = outputChannel.receive(10000);
 		assertNotNull(message);
 		assertEquals("WEBERN", message.getHeaders().get("syslog_HOST"));