InfoWindows displays content in a floating window above the map. It has a content area and tapered stem, where the tip of the stem is at specified location of marker on the map. You can see the info window by clicking particular markers on Google map. To make the info window visible, you need to call the open() method, passing google maps and marker. If no marker is provided, then the info window will open at this position property. InfoWindow needs a Info Window options object, which specifies a set of initial parameters for displaying info window.
InfoWindowOptions infoWindowOptions = InfoWindowOptions.create();
InfoWindow infoWindow = InfoWindow.create(infoWindowOptions);
(For Creation of mapWidget and marker refer previous post).