JxBrowser API provides functionality that you can use to handle loading and decide whether specified URL should be loaded in Chromium engine or not. The following example demonstrates how to register LoadHandler and cancel navigation to all URL that starts with http://www.google: 

import com.teamdev.jxbrowser.chromium.Browser;
import com.teamdev.jxbrowser.chromium.DefaultLoadHandler;
import com.teamdev.jxbrowser.chromium.LoadParams;
import com.teamdev.jxbrowser.chromium.swing.BrowserView;

import javax.swing.*;
import java.awt.*;

/**
 * This sample demonstrates how to cancel loading of a specific URL.
 */
public class LoadHandlerSample {
    public static void main(String[] args) {
        Browser browser = new Browser();
        BrowserView view = new BrowserView(browser);

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.add(view, BorderLayout.CENTER);
        frame.setSize(700, 500);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

        browser.setLoadHandler(new DefaultLoadHandler() {
            public boolean onLoad(LoadParams params) {
                // Cancel loading URL that starts with http://www.google
                return params.getURL().startsWith("http://www.google");
            }
        });
        browser.loadURL("http://www.google.com");
    }
} 

If you run the example above, you should see a white screen that indicates that the requested URL loading was suppressed because of our LoadHandler implementation.