Google Maps in Java Swing Application
If you need to embed and display Google Maps in your Java Desktop Swing application, then JxBrowser Java library is what you need.
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Join For FreeIf you need to embed and display Google Maps in your Java Desktop Swing application, then JxBrowser Java library is what you need.
JxBrowser is a cross-platform Java library that allows embedding Google Chromium-based web browser component into Java Swing applications to display web pages built with HTML5, CSS3, JavaScript, AJAX etc. The Browser component that displays web pages is totally lightweight, so you can forget about well known “Mixing heavyweight and lightweight components in Java Swing” issue.
In order to embed and display Google Maps in your Java Desktop application you just need to create Browser instance, embed it into JFrame or any other Swing container and load the http://maps.google.com web page. The following simple example demonstrates how to do this:
import com.teamdev.jxbrowser.chromium.Browser;
import com.teamdev.jxbrowser.chromium.BrowserFactory;
import javax.swing.*;
import java.awt.*;
public class GoogleMapsSample {
public static void main(String[] args) {
Browser browser = BrowserFactory.create();
JFrame frame = new JFrame("JxBrowser Google Maps");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(browser.getView().getComponent(), BorderLayout.CENTER);
frame.setSize(700, 500);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
browser.loadURL("http://maps.google.com");
}
}
In this example we create Browser instance, embed it into JFrame and load http://maps.google.com into it to display Google Maps.
Once you compile and run this GoogleMapsSample in your favorite Java IDE you should see the following output:
You can find the instruction about how to use JxBrowser in your Java application in JxBrowser Programmer’s Guide.
What if we need to communicate with the loaded map from Java code? For example, provide user with ability to zoom in/out of the map from Java Swing application. In this case we need to communicate with Google Maps API via JavaScript. JxBrowser API allows executing any JavaScript code on the loaded web page.
To work with the loaded Map we need to use google.maps.Map JavaScript object. Since Google updates http://maps.google.com very often, you may not know how to access this object on the loaded web page. To avoid this issue I recommend that you embed Google Maps using your own HTML file. You just need to create the map.html file with the following content:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html { height: 100% }
body { height: 100%; margin: 0; padding: 0 }
#map-canvas { height: 100% }
</style>
<script type="text/javascript"
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB7J1zsErb9_7jxNu5KU5kIENFObAQEbl0&sensor=false">
</script>
<script type="text/javascript">
var map;
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(48.209331, 16.381302),
zoom: 4
};
map = new google.maps.Map(document.getElementById("map-canvas"),
mapOptions);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<div id="map-canvas"/>
</body>
</html>And load the map.html file using the following method:
browser.loadURL("C:\\map.html");The output should be the following:
Now we can access google.maps.Map JavaScript object and invoke its zoom in/out methods. To change zoom of the map we can use the map.setZoom(zoom:number) method. Let’s add zoom in/out buttons in our example:
import com.teamdev.jxbrowser.chromium.Browser;
import com.teamdev.jxbrowser.chromium.BrowserFactory;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class GoogleMapsSample {
public static final int MIN_ZOOM = 0;
public static final int MAX_ZOOM = 21;
/**
* In map.html file default zoom value is set to 4.
*/
private static int zoomValue = 4;
public static void main(String[] args) {
final Browser browser = BrowserFactory.create();
JButton zoomInButton = new JButton("Zoom In");
zoomInButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (zoomValue < MAX_ZOOM) {
browser.executeJavaScript("map.setZoom(" + ++zoomValue + ")");
}
}
});
JButton zoomOutButton = new JButton("Zoom Out");
zoomOutButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (zoomValue > MIN_ZOOM) {
browser.executeJavaScript("map.setZoom(" + --zoomValue + ")");
}
}
});
JPanel toolBar = new JPanel();
toolBar.add(zoomInButton);
toolBar.add(zoomOutButton);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(browser.getView().getComponent(), BorderLayout.CENTER);
frame.add(toolBar, BorderLayout.NORTH);
frame.setSize(700, 500);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
browser.loadURL("C:\\map.html");
}
}
Now you can zoom in/out the map directly from Java Swing application:
Using JxBrowser API you can invoke other methods of the google.maps.Map JavaScript object to access all the required functionality of Google Maps in your Java Swing application.
Useful Links:
- Google Maps API: https://developers.google.com/maps/documentation/javascript/reference
- JxBrowser: http://www.teamdev.com/jxbrowser
- JxBrowser API: https://s3.amazonaws.com/cloud.teamdev.com/downloads/jxbrowser/javadoc/index.html
- JxBrowser Programmer’s Guide: http://cloud.teamdev.com.s3.amazonaws.com/downloads/jxbrowser/docs/JxBrowser-PGuide.html
- Samples: https://sites.google.com/a/teamdev.com/jxbrowser-support/samples
- Licensing: http://www.teamdev.com/jxbrowser#licensing-pricing
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