Skip to main content

Calling Struts Action by Javascript

To call a struts action by Javascript on an event, you need to write a function which is invoked when the event occurs and this function makes an AJAX call. The AJAX call can send a request to the same URL which is provided in action attribute of form tag or html:form tag.

e.g. In case your action URL is something like
that you provide in action attribute of html:form, you can pass the same url to the mentioned code snippet below:

function makeRequest(url, callbackfunction)
var http_request = getXMLHttpObject();
url = url + "isComingFromAjax=true";

if (url.indexOf('?') != -1)
url = url + "&" ;
url = url + "?" ;

url = url + "isComingFromAjax=true";
http_request.onreadystatechange = callbackfunction;'POST', url.substring(0, url.indexOf('?')), true);
http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
http_request.send(url.substring(url.indexOf('?') + 1));

Some of points to be considered in given code snippet:
1. callbackfunction is the function which will be invoked when response is received
2. "isComingFromAjax=true" parameter has been added as a extra parameter to differentiate between the normal action request and the AJAX request to do any special handling on the server side.

I have not covered details of creating XMLHttpRequest Object and other AJAX related things assuming you know it. You can write the logic for handling the response received from server in callbackfunction.


Popular posts from this blog

Drools - An overview

For Java based applications the most challenging part has always been the business logic maintenance, and pick any applications which you find complex and if we ask ourself how complex it would be moving forward, the answer will always be nX times.

What do we do ? Drools comes for Rescue as a Rule Engine.

Drools provides mechanism:

a. To write business logic in simple english language
b. Easy to maintain and very simple to extend
c. Reusability of logic by defining keywords in a DSL file and using them in DSLR file.

But be careful nothing comes free, everything takes cost in terms of memory and time space.

Use Drools if you really have :

a. Business logic which you think is getting cluttered with multiple if conditions because of variety of scenarios
b. You will have growing demand of increase in the complexity
c. The business logic changes would be frequent (1 - 2 times a year would also be frequent)
d. Your server's have enough of memory as it is a memory hungary tool, it provi…

MQTT - Eclipse Paho integration for Android

For MQTT integration, recently explored Paho Android project, very simple to use, here are the steps:

Intialize a client, set required options and connect.

    MqttAndroidClient mqttClient = new MqttAndroidClient(BaseApplication.getAppContext(), broker, MQTT_CLIENT_ID);
    //Set call back class
    mqttClient.setCallback(new MqttCallbackHandler(BaseApplication.getAppContext()));
    MqttConnectOptions connOpts = new MqttConnectOptions();
    IMqttToken token = mqttClient.connect(connOpts);

Subscribe to a topic.

    token.setActionCallback(new IMqttActionListener() {
      public void onSuccess(IMqttToken arg0) {
           mqttClient.subscribe("TOPIC_NAME" + userId, 2, null, new IMqttActionListener() {
                public void onSuccess(IMqttToken asyncActionToken) {
                    Log.d(LOG_TAG, "Successfully subscribed to topic.");

                public void onFailure…

Mobile Testing

Mobile application testing falls into broadly two types:

Hardware Testing This includes testing internal hardware, screen size, resolution, space, camera, Bluetooth, WIFI etc.
Software or Application Testing This includes testing the application that are running on device. Because of types of apps this can be divided into following categories: Native appsMobile web appsHybrid apps There are some key things to be considered when testing mobile apps: Native apps have single platformNative apps are written in platforms like SDKs while Mobile web are written in html, cssNative/Hybrid apps may or may not require internet connectionMobile web apps require internet connectionNative/Hybrid apps are downloaded from playstoreMobile web apps are accessible from internet Mobile Testing complexity in comparison web applications Different range of mobile devices, screen sizes etc.Various manufactures customizationsOS types iOS, Android, Windows etc.Different versions of OS e.g. Android 4.x, 5.x, 6.x, 7.x…