@Test
public void handleError_withPreAllocateException() {
    final DownloadTaskAdapter mockTaskAdapter = mock(DownloadTaskAdapter.class);
    final ProgressAssist mockProgressAssist = mock(ProgressAssist.class);
    when(mockTaskAdapter.getProgressAssist()).thenReturn(mockProgressAssist);
    when(mockTaskAdapter.getRetryAssist()).thenReturn(null);
    when(mockProgressAssist.getSofarBytes()).thenReturn(1L);
    final Exception mockException = mock(PreAllocateException.class);

    compatListenerAssist.handleError(mockTaskAdapter, mockException);

    verify(callback, never()).retry(
            any(DownloadTaskAdapter.class), any(Throwable.class), anyInt(), anyLong());
    final ArgumentCaptor<Throwable> throwableCaptor = ArgumentCaptor.forClass(Throwable.class);
    final ArgumentCaptor<DownloadTaskAdapter> taskCaptor = ArgumentCaptor
            .forClass(DownloadTaskAdapter.class);
    verify(callback).error(taskCaptor.capture(), throwableCaptor.capture());
    assertThat(taskCaptor.getValue()).isEqualTo(mockTaskAdapter);
    assertThat(throwableCaptor.getValue())
            .isExactlyInstanceOf(FileDownloadOutOfSpaceException.class);
}
 

private void handlePreAllocate(long totalLength, String path)
        throws IOException, IllegalAccessException {

    FileDownloadOutputStream outputStream = null;
    try {

        if (totalLength != TOTAL_VALUE_IN_CHUNKED_RESOURCE) {
            outputStream = FileDownloadUtils.createOutputStream(model.getTempFilePath());
            final long breakpointBytes = new File(path).length();
            final long requiredSpaceBytes = totalLength - breakpointBytes;

            final long freeSpaceBytes = FileDownloadUtils.getFreeSpaceBytes(path);

            if (freeSpaceBytes < requiredSpaceBytes) {
                // throw a out of space exception.
                throw new FileDownloadOutOfSpaceException(freeSpaceBytes,
                        requiredSpaceBytes, breakpointBytes);
            } else if (!FileDownloadProperties.getImpl().fileNonPreAllocation) {
                // pre allocate.
                outputStream.setLength(totalLength);
            }
        }
    } finally {
        if (outputStream != null) outputStream.close();
    }
}