*/
public boolean rename(String oldpath,String newpath) {
boolean flag=false;
ChannelSftp channel=getChannel();
try {
channel.rename(oldpath, newpath);
log.info("重命名文件"+oldpath+"成功");
log.info("更新后的文件名为:"+newpath);
flag=true;
} catch (SftpException e) {
log.error("重命名文件"+oldpath+"失败");