JSF: Exibir um popup durante a execução de um evento

<a4j:commandButton
status="waitModalStatus"
title="Enviar arquivo via FTP"
actionListener="#{processoMB.sendFtp(upload)}"
image="/resources/images/16x16/up.png">

<rich:popupPanel
    id="waitModal" style="text-align:center" autosized="true" modal="true" width="200" >
<h:graphicImage library="images" name="ajaxloader32.gif" alt="ai"/><br />
    <h:outputText value="Transmitindo o arquivo, aguarde!" />
</rich:popupPanel>

<a4j:status name="waitModalStatus">
    <f:facet name="start">
        <rich:componentControl event="start" operation="show" target="waitModal" />
    </f:facet>  
    <f:facet name="stop">
        <rich:componentControl event="stop" operation="hide" target="waitModal" />
    </f:facet>
</a4j:status>

Copiar arquivos no Java

Dessa forma o arquivo de destino não é alterado durante a cópia:

1.  public static void copyFile(File source, File destination) throws IOException {  
2.      if (destination.exists())  
3.          destination.delete();  
4.   
5.      FileChannel sourceChannel = null;  
6.      FileChannel destinationChannel = null;  
7.   
8.      try {  
9.          sourceChannel = new FileInputStream(source).getChannel();  
10.          destinationChannel = new FileOutputStream(destination).getChannel();  
11.          sourceChannel.transferTo(0, sourceChannel.size(),  
12.                  destinationChannel);  
13.      } finally {  
14.          if (sourceChannel != null && sourceChannel.isOpen())  
15.              sourceChannel.close();  
16.          if (destinationChannel != null && destinationChannel.isOpen())  
17.              destinationChannel.close();  
18.     }  
19. }  

Dessa forma o arquivo de destino pode sofrer alterações:

1. public class Teste {  
2.     public static void main(String[] args) throws IOException {  
3.         File arquivoOrigem = new File("c:/temp/original.txt");  
4.         FileReader fis = new FileReader(arquivoOrigem);  
5.         BufferedReader bufferedReader = new BufferedReader(fis);  
6.         StringBuilder buffer = new StringBuilder();  
7.         String line = "";  
8.         while ((line = bufferedReader.readLine()) != null) {  
9.             buffer.append(line).append("\n");             
10.         }  
11.           
12.         fis.close();  
13.         bufferedReader.close();  
14.           
15.         File arquivoDestino = new File("C:/temp/copia.txt");  
16.         FileWriter writer = new FileWriter(arquivoDestino);  
17.         writer.write(buffer.toString());  
18.         writer.flush();  
19.         writer.close();  
20.           
21.           
22.           
23.           
24.     }  
25. } 

Fonte: http://www.guj.com.br/java/220023-copiar-arquivo-para-outro-diretorio