How to get JSON response from JSF?

Many JavaScript widgets expect data and options in JSON format. Nowadays, it is really easy to choose a cool widget and wrap it in a composite component. But the first question is how to send an AJAX request and to recieve a response in a proper JSON format. This question is often raised by JSF users. All that you need is a XHTML facelet like this one:

<f:view encoding="UTF-8" contentType="text/html"
  <h:outputText value="#{stationView.getClosestStations(param.longitude, param.latitude)}" escape="false"/>

Please consider the contentType=”text/html” (application/json will not work here) and escape=”false” in the h:outputText. The method getClosestStations() in the bean StationView produces an JSON output for a list of special Java objects. I advise to use the Gson library in order to serialize any Java object to JSON. Short example:

String[] strings = {"abc", "def", "ghi"};
Gson gson = new Gson();
gson.toJson(strings);  ==> prints ["abc", "def", "ghi"]

The XHTML file above is located under the web context. Say, under the path /rest/stations.xhtml. Ajax call in your JavaScript code should look like this one:

    url: requestContextPath + '/rest/stations.xhtml',
    type: "GET",
    data: {
        "longitude": x,
        "latitude": y
    dataType: "json",
    success: function (data) {
        $.each(data, function (i, station) {
    error: function () {

Please refer the jQuery docu for more information regarding $.ajax. Note: if you omit dataType: “json”, you have to parse the JSON string manually.

success: function (data) {
    $.each($.parseJSON(data), function (i, station) {

The response is a pure JSON string (no HTML tags) like this one:

[{"latitude":46.947045,"longitude":7.443922,"distanz":110,"name":"Bern, Bundesplatz"},{....},...]

Need more examples for JSON response in JSF? In one of my next posts I will probably explain how to implement a cool autocomplete component without writing too much code.

Related Whitepaper:

Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions

Get ready to program in a whole new way!

Functional Programming in Java will help you quickly get on top of the new, essential Java 8 language features and the functional style that will change and improve your code. This short, targeted book will help you make the paradigm shift from the old imperative way to a less error-prone, more elegant, and concise coding style that’s also a breeze to parallelize. You’ll explore the syntax and semantics of lambda expressions, method and constructor references, and functional interfaces. You’ll design and write applications better using the new standards in Java 8 and the JDK.

Get it Now!  

2 Responses to "How to get JSON response from JSF?"

  1. Mauricio says:

    See JAX-RS, there is no reason to make a xhtml in order implement a rest like service… or make a servlet..
    What are the advantages of doing that???

Leave a Reply

four − = 3

Java Code Geeks and all content copyright © 2010-2014, Exelixis Media Ltd | Terms of Use | Privacy Policy
All trademarks and registered trademarks appearing on Java Code Geeks are the property of their respective owners.
Java is a trademark or registered trademark of Oracle Corporation in the United States and other countries.
Java Code Geeks is not connected to Oracle Corporation and is not sponsored by Oracle Corporation.
Do you want to know how to develop your skillset and become a ...
Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you two of our best selling eBooks for FREE!

Get ready to Rock!
You can download the complementary eBooks using the links below: