[VFS-726]getInputStream(int bufferSize) on SftpFileObject effectively ig

nores buffer size.

commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/bzip2/Bzip2FileObject.java

@@ -52,9 +52,9 @@ protected Bzip2FileObject(final AbstractFileName name, final FileObject containe
     }
 
     @Override
-    protected InputStream doGetInputStream() throws Exception {
+    protected InputStream doGetInputStream(final int bufferSize) throws Exception {
         // check file
-        final InputStream is = getContainer().getContent().getInputStream();
+        final InputStream is = getContainer().getContent().getInputStream(bufferSize);
         return wrapInputStream(getName().getURI(), is);
     }
 

commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/ftp/FTPClientWrapper.java

@@ -250,6 +250,20 @@ public InputStream retrieveFileStream(final String relPath) throws IOException {
         }
     }
 
+    @Override
+    public InputStream retrieveFileStream(final String relPath, final int bufferSize) throws IOException {
+        try {
+            final FTPClient client = getFtpClient();
+            client.setBufferSize(bufferSize);
+            return client.retrieveFileStream(relPath);
+        } catch (final IOException e) {
+            disconnect();
+            final FTPClient client = getFtpClient();
+            client.setBufferSize(bufferSize);
+            return client.retrieveFileStream(relPath);
+        }
+    }
+
     @Override
     public InputStream retrieveFileStream(final String relPath, final long restartOffset) throws IOException {
         try {
@@ -264,6 +278,11 @@ public InputStream retrieveFileStream(final String relPath, final long restartOf
         }
     }
 
+    @Override
+    public void setBufferSize(final int bufferSize) throws FileSystemException {
+        getFtpClient().setBufferSize(bufferSize);
+    }
+
     @Override
     public OutputStream storeFileStream(final String relPath) throws IOException {
         try {

commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/ftp/FtpClient.java

@@ -57,8 +57,17 @@ default int getReplyCode() throws IOException {
 
     InputStream retrieveFileStream(String relPath) throws IOException;
 
+    default InputStream retrieveFileStream(String relPath, int bufferSize) throws IOException {
+        // Backward compatibility: no buffer size.
+        return retrieveFileStream(relPath);
+    }
+
     InputStream retrieveFileStream(String relPath, long restartOffset) throws IOException;
 
+    default void setBufferSize(int bufferSize) throws FileSystemException {
+        // Backward compatibility: do nothing.
+    }
+
     OutputStream storeFileStream(String relPath) throws IOException;
 
 }