--- old/src/share/classes/java/io/UncheckedIOException.java	2013-02-01 14:41:02.524350613 -0800
+++ new/src/share/classes/java/io/UncheckedIOException.java	2013-02-01 14:41:02.336350616 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,6 +24,8 @@
  */
 package java.io;
 
+import java.util.Objects;
+
 /**
  * Wraps an <code>{@link IOException}</code> with an unchecked exception
  *
@@ -31,16 +33,59 @@
  * @since   JDK1.8
  */
 public class UncheckedIOException extends RuntimeException {
+    private static final long serialVersionUID = -8134305061645241065L;
+
+    /**
+     * Constructs an instance of this class.
+     *
+     * @param   message
+     *          the detail message
+     * @param   cause
+     *          the {@code IOException}
+     *
+     * @throws  NullPointerException
+     *          if the cause is {@code null}
+     */
     public UncheckedIOException(String message, IOException cause) {
-        super(message, cause);
+        super(message, Objects.requireNonNull(cause));
     }
 
+    /**
+     * Constructs an instance of this class.
+     *
+     * @param   cause
+     *          the {@code IOException}
+     *
+     * @throws  NullPointerException
+     *          if the cause is {@code null}
+     */
     public UncheckedIOException(IOException cause) {
-        super(cause);
+        super(Objects.requireNonNull(cause));
     }
 
+    /**
+     * Returns the cause of this exception.
+     *
+     * @return  the cause
+     */
     @Override
     public IOException getCause() {
         return (IOException) super.getCause();
     }
+
+    /**
+     * Called to read the object from a stream.
+     *
+     * @throws  InvalidObjectException
+     *          if the object is invalid or has a cause that is not
+     *          an {@code IOException}
+     */
+    private void readObject(ObjectInputStream s)
+        throws IOException, ClassNotFoundException
+    {
+        s.defaultReadObject();
+        Throwable cause = super.getCause();
+        if (!(cause instanceof IOException))
+            throw new InvalidObjectException("Cause must be an IOException");
+    }
 }