INT-3684: Rebuild Tail Command on Restart

JIRA: https://jira.spring.io/browse/INT-3684

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

Conflicts:
	spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests-context.xml
	spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests.java

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

@@ -31,6 +31,7 @@ import org.springframework.util.Assert;
  * Default options are "-F -n 0" (follow file name, no existing records).
  *
  * @author Gary Russell
+ * @author Gavin Gray
  * @since 3.0
  *
  */
@@ -56,6 +57,10 @@ public class OSDelegatingFileTailingMessageProducer extends FileTailingMessagePr
 		}
 	}
 
+	public String getCommand() {
+		return this.command;
+	}
+
 	@Override
 	public String getComponentType() {
 		return super.getComponentType() + " (native)";
@@ -65,13 +70,13 @@ public class OSDelegatingFileTailingMessageProducer extends FileTailingMessagePr
 	protected void onInit() {
 		Assert.notNull(getFile(), "File cannot be null");
 		super.onInit();
-		this.command = "tail " + this.options + " " + this.getFile().getAbsolutePath();
 	}
 
 	@Override
 	protected void doStart() {
 		super.doStart();
 		destroyProcess();
+		this.command = "tail " + this.options + " " + this.getFile().getAbsolutePath();
 		this.getTaskExecutor().execute(new Runnable() {
 
 			@Override
@@ -257,5 +262,4 @@ public class OSDelegatingFileTailingMessageProducer extends FileTailingMessagePr
 		}
 	}
 
-
 }

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests-context.xml

@@ -13,11 +13,13 @@
 		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
 		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
 
+	<int:channel id="tailErrorChannel"/>
+
 	<int-file:tail-inbound-channel-adapter id="default"
 		channel="input"
 		task-executor="exec"
 		file="/tmp/baz"
-		auto-startup="false"
+		auto-startup="true"
 		phase="123" />
 
 	<int-file:tail-inbound-channel-adapter id="native"
@@ -27,7 +29,7 @@
 		task-scheduler="sched"
 		file-delay="456"
 		file="/tmp/foo"
-		auto-startup="false"
+		auto-startup="true"
 		delay="${empty}"
 		end="${empty}"
 		reopen="${empty}"
@@ -63,7 +65,8 @@
 
 	<int:channel id="input" />
 	
-	<task:executor id="exec" />
-
 	<task:scheduler id="sched" />
+
+	<bean class="org.springframework.integration.file.config.FileTailInboundChannelAdapterParserTests$Config" />
+
 </beans>

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileTailInboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -18,6 +18,8 @@ package org.springframework.integration.file.config;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
 
 import java.io.File;
 
@@ -26,6 +28,7 @@ import org.junit.runner.RunWith;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Bean;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.integration.file.tail.ApacheCommonsFileTailingMessageProducer;
 import org.springframework.integration.file.tail.OSDelegatingFileTailingMessageProducer;
@@ -36,6 +39,7 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 /**
  * @author Gary Russell
+ * @author Gavin Gray
  * @since 3.0
  *
  */
@@ -71,8 +75,12 @@ public class FileTailInboundChannelAdapterParserTests {
 		assertEquals("/tmp/baz", normalizedName);
 		assertEquals("tail -F -n 0 " + fileName, TestUtils.getPropertyValue(defaultAdapter, "command"));
 		assertSame(exec, TestUtils.getPropertyValue(defaultAdapter, "taskExecutor"));
-		assertFalse(TestUtils.getPropertyValue(defaultAdapter, "autoStartup", Boolean.class));
+		assertTrue(TestUtils.getPropertyValue(defaultAdapter, "autoStartup", Boolean.class));
 		assertEquals(123, TestUtils.getPropertyValue(defaultAdapter, "phase"));
+		this.defaultAdapter.stop();
+		this.defaultAdapter.setOptions("-F -n 6");
+		this.defaultAdapter.start();
+		assertEquals("tail -F -n 6 " + fileName, TestUtils.getPropertyValue(defaultAdapter, "command"));
 	}
 
 	@Test
@@ -83,7 +91,7 @@ public class FileTailInboundChannelAdapterParserTests {
 		assertEquals("tail -F -n 6 " + fileName, TestUtils.getPropertyValue(nativeAdapter, "command"));
 		assertSame(exec, TestUtils.getPropertyValue(nativeAdapter, "taskExecutor"));
 		assertSame(sched, TestUtils.getPropertyValue(nativeAdapter, "taskScheduler"));
-		assertFalse(TestUtils.getPropertyValue(nativeAdapter, "autoStartup", Boolean.class));
+		assertTrue(TestUtils.getPropertyValue(nativeAdapter, "autoStartup", Boolean.class));
 		assertEquals(123, TestUtils.getPropertyValue(nativeAdapter, "phase"));
 		assertEquals(456L, TestUtils.getPropertyValue(nativeAdapter, "tailAttemptsDelay"));
 	}
@@ -127,4 +135,14 @@ public class FileTailInboundChannelAdapterParserTests {
 		}
 		return absolutePath;
 	}
+
+	public static class Config {
+
+		@Bean
+		public TaskExecutor exec() {
+			return mock(TaskExecutor.class);
+		}
+
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -22,6 +22,7 @@ import static org.mockito.Mockito.mock;
 
 import java.io.File;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -42,6 +43,7 @@ import org.springframework.messaging.Message;
 
 /**
  * @author Gary Russell
+ * @author Gavin Gray
  * @since 3.0
  *
  */
@@ -90,6 +92,37 @@ public class FileTailingMessageProducerTests {
 		testGuts(adapter, "tailer");
 	}
 
+	@Test
+	@TailAvailable
+	public void canRecalculateCommandWhenFileOrOptionsChanged() throws IOException {
+		File firstFile = File.createTempFile("first", ".txt");
+		String firstOptions = "-f options";
+		File secondFile = File.createTempFile("second", ".txt");
+		String secondOptions = "-f newoptions";
+		OSDelegatingFileTailingMessageProducer adapter = new OSDelegatingFileTailingMessageProducer();
+		adapter.setFile(firstFile);
+		adapter.setOptions(firstOptions);
+
+		adapter.setOutputChannel(new QueueChannel());
+		adapter.setTailAttemptsDelay(500);
+		adapter.setBeanFactory(mock(BeanFactory.class));
+		adapter.afterPropertiesSet();
+
+		adapter.start();
+		assertEquals("tail " + firstOptions + " " + firstFile.getAbsolutePath(), adapter.getCommand());
+		adapter.stop();
+
+		adapter.setFile(secondFile);
+		adapter.start();
+		assertEquals("tail " + firstOptions + " " + secondFile.getAbsolutePath(), adapter.getCommand());
+		adapter.stop();
+
+		adapter.setOptions(secondOptions);
+		adapter.start();
+		assertEquals("tail " + secondOptions + " " + secondFile.getAbsolutePath(), adapter.getCommand());
+		adapter.stop();
+	}
+
 	private void testGuts(FileTailingMessageProducerSupport adapter, String field)
 			throws Exception {
 		this.adapter = adapter;