Fix TomcatContextCustomizers Assert.notNull checks

Correct null assertion checks on setters for TomcatContextCustomizers
and TomcatContextCustomizers

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactory.java

@@ -371,7 +371,7 @@ public class TomcatEmbeddedServletContainerFactory extends
 	 */
 	public void setTomcatContextCustomizers(
 			Collection<? extends TomcatContextCustomizer> tomcatContextCustomizers) {
-		Assert.notNull(this.contextLifecycleListeners,
+		Assert.notNull(tomcatContextCustomizers,
 				"TomcatContextCustomizers must not be null");
 		this.tomcatContextCustomizers = new ArrayList<TomcatContextCustomizer>(
 				tomcatContextCustomizers);
@@ -392,8 +392,8 @@ public class TomcatEmbeddedServletContainerFactory extends
 	 * @param tomcatContextCustomizers the customizers to add
 	 */
 	public void addContextCustomizers(TomcatContextCustomizer... tomcatContextCustomizers) {
-		Assert.notNull(this.tomcatContextCustomizers,
-				"TomcatContextCustomizer must not be null");
+		Assert.notNull(tomcatContextCustomizers,
+				"TomcatContextCustomizers must not be null");
 		this.tomcatContextCustomizers.addAll(Arrays.asList(tomcatContextCustomizers));
 	}
 
@@ -404,8 +404,8 @@ public class TomcatEmbeddedServletContainerFactory extends
 	 */
 	public void setTomcatConnectorCustomizers(
 			Collection<? extends TomcatConnectorCustomizer> tomcatConnectorCustomizers) {
-		Assert.notNull(this.contextLifecycleListeners,
-				"TomcatConnectorCustomizer must not be null");
+		Assert.notNull(tomcatConnectorCustomizers,
+				"TomcatConnectorCustomizers must not be null");
 		this.tomcatConnectorCustomizers = new ArrayList<TomcatConnectorCustomizer>(
 				tomcatConnectorCustomizers);
 	}
@@ -417,8 +417,8 @@ public class TomcatEmbeddedServletContainerFactory extends
 	 */
 	public void addConnectorCustomizers(
 			TomcatConnectorCustomizer... tomcatConnectorCustomizers) {
-		Assert.notNull(this.tomcatContextCustomizers,
-				"TomcatConnectorCustomizer must not be null");
+		Assert.notNull(tomcatConnectorCustomizers,
+				"TomcatConnectorCustomizers must not be null");
 		this.tomcatConnectorCustomizers.addAll(Arrays.asList(tomcatConnectorCustomizers));
 	}
 

spring-boot/src/test/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactoryTests.java

 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -138,6 +138,38 @@ public class TomcatEmbeddedServletContainerFactoryTests extends
 		verify(valve).setNext(any(Valve.class));
 	}
 
+	@Test
+	public void setNullTomcatContextCustomizersThrows() {
+		TomcatEmbeddedServletContainerFactory factory = getFactory();
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("TomcatContextCustomizers must not be null");
+		factory.setTomcatContextCustomizers(null);
+	}
+
+	@Test
+	public void addNullContextCustomizersThrows() {
+		TomcatEmbeddedServletContainerFactory factory = getFactory();
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("TomcatContextCustomizers must not be null");
+		factory.addContextCustomizers((TomcatContextCustomizer[]) null);
+	}
+
+	@Test
+	public void setNullTomcatConnectorCustomizersThrows() {
+		TomcatEmbeddedServletContainerFactory factory = getFactory();
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("TomcatConnectorCustomizers must not be null");
+		factory.setTomcatConnectorCustomizers(null);
+	}
+
+	@Test
+	public void addNullConnectorCustomizersThrows() {
+		TomcatEmbeddedServletContainerFactory factory = getFactory();
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("TomcatConnectorCustomizers must not be null");
+		factory.addConnectorCustomizers((TomcatConnectorCustomizer[]) null);
+	}
+
 	private void assertTimeout(TomcatEmbeddedServletContainerFactory factory, int expected) {
 		this.container = factory.getEmbeddedServletContainer();
 		Tomcat tomcat = ((TomcatEmbeddedServletContainer) this.container).getTomcat();