用websocket更改servlet上的图片

I have a small website that each times an user cliks on an image, it changes. It is made on HTML5, JS, Java and Wildfly. Does anyone know how do I update the image for the others users browsers as well? I mean, each time someone clicks on the image, it changes, and I want it to change on the other users that are on my website by the moment as well. I made the connection of JavaScript and Java with JSON, but how can I send a message from Java to Javascript? With JSON again?I have a small website that each times an user