Javadoc.

src/main/java/org/apache/commons/io/input/BufferedFileChannelInputStream.java

@@ -157,6 +157,7 @@ public synchronized int read(final byte[] b, final int offset, int len) throws I
      * Checks whether data is left to be read from the input stream.
      *
      * @return true if data is left, false otherwise
+     * @throws IOException if an I/O error occurs.
      */
     private boolean refill() throws IOException {
         if (!byteBuffer.hasRemaining()) {

src/main/java/org/apache/commons/io/input/ReadAheadInputStream.java

@@ -283,7 +283,11 @@ public int read(final byte[] b, final int offset, int len) throws IOException {
         return len;
     }
 
-    /** Read data from underlyingInputStream to readAheadBuffer asynchronously. */
+    /** 
+     * Read data from underlyingInputStream to readAheadBuffer asynchronously.
+     *
+     * @throws IOException if an I/O error occurs.
+     */
     private void readAsync() throws IOException {
         stateChangeLock.lock();
         final byte[] arr;
@@ -398,6 +402,7 @@ public long skip(final long n) throws IOException {
      *
      * @param n the number of bytes to be skipped.
      * @return the actual number of bytes skipped.
+     * @throws IOException if an I/O error occurs.
      */
     private long skipInternal(final long n) throws IOException {
         assert stateChangeLock.isLocked();