Add progress listener interface to copy operation.

diff --git a/src/de/todesbaum/util/io/StreamCopier.java b/src/de/todesbaum/util/io/StreamCopier.java
index dccd09a..ee87c19 100644 (file)
--- a/src/de/todesbaum/util/io/StreamCopier.java
+++ b/src/de/todesbaum/util/io/StreamCopier.java
@@ -20,6 +20,7 @@ import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.EventListener;
 
 /**
  * Copies input from an {@link InputStream} to an {@link OutputStream}.
@@ -105,6 +106,23 @@ public class StreamCopier {
        }
 
        /**
+        * Copies the stream data. If the input stream is depleted before the
+        * requested number of bytes have been read an {@link EOFException} is
+        * thrown.
+        *
+        * @param progressListener
+        *            The progress listener (may be {@code null})
+        * @throws EOFException
+        *             if the input stream is depleted before the requested number
+        *             of bytes has been read
+        * @throws IOException
+        *             if an I/O error occurs
+        */
+       public void copy(ProgressListener progressListener) throws EOFException, IOException {
+               copy(inputStream, outputStream, length, bufferSize, progressListener);
+       }
+
+       /**
         * Copies <code>length</code> bytes from the <code>inputStream</code> to
         * the <code>outputStream</code>.
         *
@@ -123,6 +141,25 @@ public class StreamCopier {
 
        /**
         * Copies <code>length</code> bytes from the <code>inputStream</code> to
+        * the <code>outputStream</code>.
+        *
+        * @param inputStream
+        *            The input stream to read from
+        * @param outputStream
+        *            The output stream to write to
+        * @param length
+        *            The number of bytes to copy
+        * @param progressListener
+        *            The progress listener (may be {@code null})
+        * @throws IOException
+        *             if an I/O exception occurs
+        */
+       public static void copy(InputStream inputStream, OutputStream outputStream, long length, ProgressListener progressListener) throws IOException {
+               copy(inputStream, outputStream, length, BUFFER_SIZE, progressListener);
+       }
+
+       /**
+        * Copies <code>length</code> bytes from the <code>inputStream</code> to
         * the <code>outputStream</code> using a buffer with the specified size
         *
         * @param inputStream
@@ -137,6 +174,27 @@ public class StreamCopier {
         *             if an I/O exception occurs
         */
        public static void copy(InputStream inputStream, OutputStream outputStream, long length, int bufferSize) throws IOException {
+               copy(inputStream, outputStream, length, bufferSize, null);
+       }
+
+       /**
+        * Copies <code>length</code> bytes from the <code>inputStream</code> to
+        * the <code>outputStream</code> using a buffer with the specified size
+        *
+        * @param inputStream
+        *            The input stream to read from
+        * @param outputStream
+        *            The output stream to write to
+        * @param length
+        *            The number of bytes to copy
+        * @param bufferSize
+        *            The size of the copy buffer
+        * @param progressListener
+        *            The progress listener (may be {@code null})
+        * @throws IOException
+        *             if an I/O exception occurs
+        */
+       public static void copy(InputStream inputStream, OutputStream outputStream, long length, int bufferSize, ProgressListener progressListener) throws IOException {
                long remaining = length;
                byte[] buffer = new byte[bufferSize];
                while (remaining > 0) {
@@ -146,7 +204,30 @@ public class StreamCopier {
                        }
                        outputStream.write(buffer, 0, read);
                        remaining -= read;
+                       if (progressListener != null) {
+                               progressListener.onProgress(length - remaining, length);
+                       }
                }
        }
 
+       /**
+        * Interface for objects that want to be notified about the progress of a
+        * {@link StreamCopier#copy()} operation.
+        *
+        * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
+        */
+       public static interface ProgressListener extends EventListener {
+
+               /**
+                * Notifiies a listener that a copy process made some progress.
+                *
+                * @param copied
+                *            The number of bytes that have already been copied
+                * @param length
+                *            The total number of bytes that will be copied
+                */
+               public void onProgress(long copied, long length);
+
+       }
+
 }