How do I connect database to the application?

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Java

MySQL

i did a program to save inquiries and send those inquiries to people who responsible.
i have completed the application and we have 20 networked computers with me.
i wanted to install the program to each computer and runs it.

when someone login into my application,
user have to fill the form and when they submit it.. email goes to responsible user.
and the other end data goes to database and save.
so now i want to do this same procedure in another computer.

try{
        Class.forName("com.mysql.jdbc.Driver");
        connect=DriverManager.getConnection("jdbc:mysql://localhost:3306/userdb","root","");
        preSt=connect.prepareStatement("insert into enqsheet values(?,?,?,?,?,?,?,?,?,?)");

what happened if i put my ipaddress instead localhost or how can i make it accessible from other computers.

is there any possible way to attach this database for each application?

What I have tried:

i have clean and build the application.
then i got java.jar file.
i double clicked it and opened it in another computer.
so it gives packet not sent and communication error.
but email will send to the user.