diff --git a/org.springframework.core/src/main/java/org/springframework/core/io/AbstractResource.java b/org.springframework.core/src/main/java/org/springframework/core/io/AbstractResource.java
index 20b44df103..33f7658b37 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/io/AbstractResource.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/io/AbstractResource.java
@@ -25,7 +25,6 @@ import java.net.URISyntaxException;
 import java.net.URL;
 
 import org.springframework.core.NestedIOException;
-import org.springframework.util.Assert;
 import org.springframework.util.ResourceUtils;
 
 /**
@@ -113,16 +112,14 @@ public abstract class AbstractResource implements Resource {
 	 * content length. Subclasses will almost always be able to provide
 	 * a more optimal version of this, e.g. checking a File length.
 	 * @see #getInputStream()
-	 * @throws IllegalStateException if {@link #getInputStream()} returns null.
 	 */
 	public long contentLength() throws IOException {
-		InputStream is = this.getInputStream();
-		Assert.state(is != null, "resource input stream must not be null");
+		InputStream is = getInputStream();
 		try {
 			long size = 0;
 			byte[] buf = new byte[255];
 			int read;
-			while((read = is.read(buf)) != -1) {
+			while ((read = is.read(buf)) != -1) {
 				size += read;
 			}
 			return size;
diff --git a/org.springframework.core/src/main/java/org/springframework/core/io/InputStreamSource.java b/org.springframework.core/src/main/java/org/springframework/core/io/InputStreamSource.java
index 33bac47915..7e1f58a0c7 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/io/InputStreamSource.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/io/InputStreamSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -47,6 +47,7 @@ public interface InputStreamSource {
 	 * as JavaMail, which needs to be able to read the stream multiple times when
 	 * creating mail attachments. For such a use case, it is <i>required</i>
 	 * that each <code>getInputStream()</code> call returns a fresh stream.
+	 * @return the input stream for the underlying resource (must not be {@code null})
 	 * @throws IOException if the stream could not be opened
 	 * @see org.springframework.mail.javamail.MimeMessageHelper#addAttachment(String, InputStreamSource)
 	 */
diff --git a/org.springframework.core/src/main/java/org/springframework/core/io/Resource.java b/org.springframework.core/src/main/java/org/springframework/core/io/Resource.java
index 0d088b9202..b242ffc2c4 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/io/Resource.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/io/Resource.java
@@ -133,9 +133,4 @@ public interface Resource extends InputStreamSource {
 	 */
 	String getDescription();
 
-	/**
-	 * {@inheritDoc}
-	 * @return the input stream for the underlying resource (must not be {@code null}).
-	 */
-	public InputStream getInputStream() throws IOException;
 }