Question

I have a database which contains users, roles, and permissions. I want to be able to map this to the front end (Java Swing) so a user who can’t do an action can’t see it.

An example:

• Role AddressManager has permissions create_address, edit_address and
  remove_address.
• User A has permissions create_address and edit_address.
• User B has permission remove_address.

I want three buttons for the address view that represent the roles from the AddressManager, and for the users A and B to enable / disable the buttons.

Question: Is there any easy way to map database table values to Swing components (Buttons)?

One way is to assign enable/disable manually to every single component, but that’s unpractical if there are 40 dialogs in the application with about 200 components that must have permission.

Answer 1

What you can do is to write a class like this and use it everywhere.
In your example you would add it with new ActionContainer(“adress”); and it will create a create_address, edit_address, delete_address Button that are enabled if the user posses the matching right.

package de.steamnet.samples;

// This class is a Panel that renders buttons based on rights.

import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JPanel;

public class ActionContainer extends JPanel {
    List<JButton> buttons = new ArrayList<JButton>();

    public ActionContainer(String rightBase) {
        List<String> rights = database.getRightsStartingWith(rightBase);
        for(String nextRight : rights) {
            JButton next = new JButton(nextRight);
            buttons.add(next);
            if(user.hasRight(nextRight)) {
                next.setEnabled(true);
            } else {
                next.setEnabled(false);
            }
            add(next);
        }
    }

    public void addActionListener(ActionListener al) {
        for(JButton next: buttons) {
            next.addActionListener(al);
        }
    }
}