以下代码在pc上测试通过，可是在android模拟器上就不工作，不过还可以链接到服务器但不能得到文件 纠结了半天，原来是模式的问题，具体请Google 模拟器中采用建议被动模式

public void getWorkMessage(){                  FTPClient ftp = new FTPClient();            try {          ftp.connect(server);                    System.out.println("Connected to " + server);          System.out.print(ftp.getReplyString());            reply = ftp.getReplyCode();                    if(!FTPReply.isPositiveCompletion(reply)) {              ftp.disconnect();              System.err.println("FTP server refused connection.");              System.exit(1);           }          ftp.login(username, password);                    FTPFile[] files = ftp.listFiles("/");                    if(files!=null&&files.length>0){                            for(FTPFile f:files){                                    System.out.println("user:>>>"+f.getUser()+" name:>>>"+f.getName()+" size:>>>"+f.getSize()+" link:>>>"+f.getLink());                                }          }      } catch (SocketException e) {                    e.printStackTrace();      } catch (IOException e) {                    e.printStackTrace();      }              }

 加上被动模式之后，代码如下：

public void getWorkMessage(){                              FTPClient ftp = new FTPClient();                    try {              ftp.connect(server);                            System.out.println("Connected to " + server);              System.out.print(ftp.getReplyString());                reply = ftp.getReplyCode();                            if(!FTPReply.isPositiveCompletion(reply)) {                  ftp.disconnect();                  System.err.println("FTP server refused connection.");                  System.exit(1);               }              ftp.login(username, password);                           //设置为被动模式             ftp.enterLocalPassiveMode();                            FTPFile[] files = ftp.listFiles("/");                            if(files!=null&&files.length>0){                                    for(FTPFile f:files){                                            System.out.println("user:>>>"+f.getUser()+" name:>>>"+f.getName()+" size:>>>"+f.getSize()+" link:>>>"+f.getLink());                                        }              }          } catch (SocketException e) {                            e.printStackTrace();          } catch (IOException e) {                            e.printStackTrace();          }                          }

OK,这样就可以了。