mysqldump creates a blank file using java

Question

Goodmorning everyone. I have a problem with my java program: i would like to create a directory to store a .sql file, which will be generated through mysqldump.exe. I've been trying to follow guides on Stack Overflow or others, but i still can't resolve my problem: directory and .sql file are generated, but the file is totally blank. The best part is that pasting the same command (ctrl+C, ctrl+V) on the command line, it works well and generates an ordinary .sql file for a dump operation.

Please help me. I'm using NetBeans 8.0.2 as IDE, there's my code (there are some variables, like SelectedTable, that allows me to get the current user, password etc. Don't care about them: those parts works and the command is correctly generated):

 private void jMenuExternalBackupActionPerformed(java.awt.event.ActionEvent evt) { 
 LocalDate today = LocalDate.now();
 GregorianCalendar now = new GregorianCalendar();
 String BackupFolderName = SelectedTable.getMaster().getName()+" "+SelectedTable.getName()+" "+today.getYear()+"_"+today.getMonth().getValue()+"_"+today.getDayOfMonth()+" "+now.get(now.HOUR_OF_DAY)+"_"+now.get(now.MINUTE)+"_"+now.get(now.SECOND);
 new File("/HyperSQL/Backups/").mkdirs();
 new File("/HyperSQL/Backups/"+BackupFolderName+"/").mkdirs();
 String command; 
 if (SelectedTable.getMasterApplication().getPassword().isEmpty())
 command = "mysqldump -u" + SelectedTable.getMasterApplication().getUserLogged() + " " + SelectedTable.getMaster().getName() + ""
 + " > \"C:\\HyperSQL\\Backups\\"+BackupFolderName+"\\backup.sql\"";
 else
 command = "mysqldump -u" + SelectedTable.getMasterApplication().getUserLogged() + " -p" + SelectedTable.getMasterApplication().getPassword() + " " + SelectedTable.getMaster().getName() + ""
 + " > \"C:\\HyperSQL\\Backups\\"+BackupFolderName+"\\backup.sql\""; 
 try
 {
 Process exec = Runtime.getRuntime().exec(new String[]{"cmd.exe","/c", command});
 }
 catch (Exception e)
 {
 e.printStackTrace();
 }
} 

• Ankit Tripathi: Possible duplicate of stackoverflow.com/questions/5969724/…
• Stephen C: Is the "mysqldump" program on the command search path? Try using the full pathname for mysqldump instead.
• kucing_terbang: hmm, you might want to print out the content of the output stream and error stream to make sure there is no error.
• Daniele Manicardi: @StephenC i tried to but it doesn't create the file...
• Stephen C: Have you tried looking at the error message (stderr) and the exit status?