import java.util.*;
import java.io.*;
public class BackUpSql {
public static void main(String[] args) {
try {
Runtime rt = Runtime.getRuntime();
rt.exec("cmd.exe /c start C:\\ab.bat");
System.exit(0);
}
catch(Exception ex){
ex.printStackTrace();
}
}
}

Here is the ab.bat:

set path=%path%;C:\Program files\MySQL\MySQL Server 5.0\bin;
mysqldump -uroot -proot register>C:\back.sql

where root is the username and password and register is the database.

For more information, visit the following link:

http://www.roseindia.net/mysql/mysqlbackuprestore.shtml