diff --git a/spring-core/src/main/java/org/springframework/core/env/EnumerablePropertySource.java b/spring-core/src/main/java/org/springframework/core/env/EnumerablePropertySource.java
index 5c30764f63b..bcd220e6ddd 100644
--- a/spring-core/src/main/java/org/springframework/core/env/EnumerablePropertySource.java
+++ b/spring-core/src/main/java/org/springframework/core/env/EnumerablePropertySource.java
@@ -45,8 +45,6 @@ import org.springframework.util.Assert;
  */
 public abstract class EnumerablePropertySource<T> extends PropertySource<T> {
 
-	protected static final String[] EMPTY_NAMES_ARRAY = new String[0];
-
 	protected final Log logger = LogFactory.getLog(getClass());
 
 
diff --git a/spring-core/src/main/java/org/springframework/core/env/MapPropertySource.java b/spring-core/src/main/java/org/springframework/core/env/MapPropertySource.java
index b8b62706c1b..b8537bed635 100644
--- a/spring-core/src/main/java/org/springframework/core/env/MapPropertySource.java
+++ b/spring-core/src/main/java/org/springframework/core/env/MapPropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 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.
@@ -18,6 +18,8 @@ package org.springframework.core.env;
 
 import java.util.Map;
 
+import org.springframework.util.StringUtils;
+
 /**
  * {@link PropertySource} that reads keys and values from a {@code Map} object.
  *
@@ -38,7 +40,7 @@ public class MapPropertySource extends EnumerablePropertySource<Map<String, Obje
 
 	@Override
 	public String[] getPropertyNames() {
-		return this.source.keySet().toArray(EMPTY_NAMES_ARRAY);
+		return StringUtils.toStringArray(this.source.keySet());
 	}
 
 }
diff --git a/spring-core/src/main/java/org/springframework/core/env/MutablePropertySources.java b/spring-core/src/main/java/org/springframework/core/env/MutablePropertySources.java
index 83ad9086ac1..da01276df1d 100644
--- a/spring-core/src/main/java/org/springframework/core/env/MutablePropertySources.java
+++ b/spring-core/src/main/java/org/springframework/core/env/MutablePropertySources.java
@@ -21,6 +21,7 @@ import java.util.LinkedList;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -187,7 +188,7 @@ public class MutablePropertySources implements PropertySources {
 	}
 
 	@Override
-	public synchronized String toString() {
+	public String toString() {
 		String[] names = new String[this.size()];
 		for (int i=0; i < size(); i++) {
 			names[i] = this.propertySourceList.get(i).getName();
diff --git a/spring-web/src/main/java/org/springframework/web/context/support/ServletConfigPropertySource.java b/spring-web/src/main/java/org/springframework/web/context/support/ServletConfigPropertySource.java
index c933827cff3..212b9a302df 100644
--- a/spring-web/src/main/java/org/springframework/web/context/support/ServletConfigPropertySource.java
+++ b/spring-web/src/main/java/org/springframework/web/context/support/ServletConfigPropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 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.
@@ -20,7 +20,7 @@ import javax.servlet.ServletConfig;
 
 import org.springframework.core.env.EnumerablePropertySource;
 import org.springframework.core.env.PropertySource;
-import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link PropertySource} that reads init parameters from a {@link ServletConfig} object.
@@ -37,8 +37,7 @@ public class ServletConfigPropertySource extends EnumerablePropertySource<Servle
 
 	@Override
 	public String[] getPropertyNames() {
-		return CollectionUtils.toArray(
-				this.source.getInitParameterNames(), EMPTY_NAMES_ARRAY);
+		return StringUtils.toStringArray(this.source.getInitParameterNames());
 	}
 
 	@Override
diff --git a/spring-web/src/main/java/org/springframework/web/context/support/ServletContextPropertySource.java b/spring-web/src/main/java/org/springframework/web/context/support/ServletContextPropertySource.java
index d5c3cdbf1c0..0fb48c9e5a1 100644
--- a/spring-web/src/main/java/org/springframework/web/context/support/ServletContextPropertySource.java
+++ b/spring-web/src/main/java/org/springframework/web/context/support/ServletContextPropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -20,7 +20,7 @@ import javax.servlet.ServletContext;
 
 import org.springframework.core.env.EnumerablePropertySource;
 import org.springframework.core.env.PropertySource;
-import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link PropertySource} that reads init parameters from a {@link ServletContext} object.
@@ -37,12 +37,12 @@ public class ServletContextPropertySource extends EnumerablePropertySource<Servl
 
 	@Override
 	public String[] getPropertyNames() {
-		return CollectionUtils.toArray(
-				this.source.getInitParameterNames(), EMPTY_NAMES_ARRAY);
+		return StringUtils.toStringArray(this.source.getInitParameterNames());
 	}
 
 	@Override
 	public String getProperty(String name) {
 		return this.source.getInitParameter(name);
 	}
+
 }
diff --git a/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletConfigPropertySource.java b/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletConfigPropertySource.java
index e4e9f6ca8ce..09d2457866b 100644
--- a/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletConfigPropertySource.java
+++ b/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletConfigPropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 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.
@@ -20,7 +20,7 @@ import javax.portlet.PortletConfig;
 
 import org.springframework.core.env.EnumerablePropertySource;
 import org.springframework.core.env.PropertySource;
-import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link PropertySource} that reads init parameters from a {@link PortletConfig} object.
@@ -37,11 +37,12 @@ public class PortletConfigPropertySource extends EnumerablePropertySource<Portle
 
 	@Override
 	public String[] getPropertyNames() {
-		return CollectionUtils.toArray(this.source.getInitParameterNames(), EMPTY_NAMES_ARRAY);
+		return StringUtils.toStringArray(this.source.getInitParameterNames());
 	}
 
 	@Override
 	public String getProperty(String name) {
 		return this.source.getInitParameter(name);
 	}
+
 }
diff --git a/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletContextPropertySource.java b/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletContextPropertySource.java
index 4a79a28ea13..06274237452 100644
--- a/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletContextPropertySource.java
+++ b/spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/PortletContextPropertySource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 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.
@@ -20,7 +20,7 @@ import javax.portlet.PortletContext;
 
 import org.springframework.core.env.EnumerablePropertySource;
 import org.springframework.core.env.PropertySource;
-import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link PropertySource} that reads init parameters from a {@link PortletContext} object.
@@ -37,11 +37,12 @@ public class PortletContextPropertySource extends EnumerablePropertySource<Portl
 
 	@Override
 	public String[] getPropertyNames() {
-		return CollectionUtils.toArray(this.source.getInitParameterNames(), EMPTY_NAMES_ARRAY);
+		return StringUtils.toStringArray(this.source.getInitParameterNames());
 	}
 
 	@Override
 	public String getProperty(String name) {
 		return this.source.getInitParameter(name);
 	}
+
 }