import  org.apache.commons.net.ftp.*;
 import  java.util.Calendar;
 import  java.text.DateFormat;
 import  java.io.File;
 import  java.io.FileOutputStream;
 import  java.util.Date;

 public   class  ftpRun {
   public  ftpRun() {
  }
   public   static   void  getDataFiles(String server, String username, String password,
                                  String folder, String destinationFolder) {
     try  {
      // Connect and logon to FTP Server
      FTPClient ftp =  new  FTPClient();
      ftp.connect(server);
      ftp.login(username, password);
      // List the files in the directory
      ftp.changeWorkingDirectory(folder);
      FTPFile[] files = ftp.listFiles();
       for  ( int  i =  0 ; i < files.length; i++) {
        Date fileDate = files[i].getTimestamp().getTime();
        File file =  new  File(destinationFolder + File.separator + files[i].getName());
        FileOutputStream fos =  new  FileOutputStream(file);
        ftp.retrieveFile(files[i].getName(), fos);
        fos.close();
      }
      // Logout from the FTP Server and disconnect
      ftp.logout();
      ftp.disconnect();
    }
     catch  (Exception e) {
      e.printStackTrace();
    }
  }
}

java.lang.UnsupportedClassVersionError: org/apache/commons/net/ftp/FTPClient (Unsupported major.minor version  48 . 0 )
at java.lang.ClassLoader.defineClass0( Native  Method)	
at java.lang.ClassLoader.defineClass(ClassLoader.java: 486 )	
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java: 111 )
at com.sun.jnlp.JNLPClassLoader.defineClass(Unknown Source)
at com.sun.jnlp.JNLPClassLoader.access$ 1 (Unknown Source)
at com.sun.jnlp.JNLPClassLoader$ 1 .run(Unknown Source)	
at java.security.AccessController.doPrivileged( Native  Method)	
at com.sun.jnlp.JNLPClassLoader.findClass(Unknown Source)	
at java.lang.ClassLoader.loadClass(ClassLoader.java: 297 )	
at java.lang.ClassLoader.loadClass(ClassLoader.java: 253 )	
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java: 313 )	
at ftp.ftp.main(ftp.java: 28 )	
at java.lang.reflect.Method.invoke( Native  Method)	
at com.sun.javaws.Launcher.executeApplication(Unknown Source)	
at com.sun.javaws.Launcher.executeMainClass(Unknown Source)	
at com.sun.javaws.Launcher.continueLaunch(Unknown Source)	
at com.sun.javaws.Launcher.handleApplicationDesc(Unknown Source)	
at com.sun.javaws.Launcher.handleLaunchFile(Unknown Source)	
at com.sun.javaws.Launcher.run(Unknown Source)	
at java.lang.Thread.run(Thread.java: 484 )