How to call a SOAP web service on Android

java

android-soap

xml-parsing

httpclient

byAnton Shumikhin·Oct 30, 2024

Call a SOAP web service on Android with kSOAP2 by creating a SoapObject for the request, setting up a SoapSerializationEnvelope, and sending the request with HttpTransportSE. Here's how you do it:

SoapObject request = new SoapObject(NAMESPACE, METHOD);
request.addProperty("Param", "Value"); // "Value" is a placeholder, not a life advice

SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.setOutputSoapObject(request); 

HttpTransportSE transport = new HttpTransportSE(URL);

try {
    transport.call(SOAP_ACTION, envelope);
    SoapPrimitive response = (SoapPrimitive) envelope.getResponse();
    String result = response.toString(); // Now I speak SOAP fluently
} catch (Exception e) {
    // When life gives you SOAP, make soapade
}

Replace placeholders with actual service details. This approach swiftly guides you to create and execute a SOAP request on Android.

Diving deeper: Working with SOAP on Android

Although kSOAP2 is the silver bullet for SOAP communications in Android, bear in mind that Android leans towards REST and JSON for web services due to their inherent simplicity and lightweight nature. If SOAP usage is necessary, kSOAP2 comes to the rescue by eliminating manual XML parsing.

XmlPullParser should be your go-to for efficient and friendly XML parsing. If you're dipping your toes into Android messaging, the XMPP protocol might be worth exploring.

The NetBeans IDE could be your faithful servant for web service creation. When invoking SOAP on Android, establish server communications with HttpClient and HttpGet classes to ensure smooth sailing.

XML-based services can seem like a Gordian knot due to their intricate structure and verbosity. Dealing with SOAP implies wrestling with this complexity and sizeable overhead. Hence, always keep an eye on the efficiency of your implementation.

Tackling the SOAP overhead

XML verbosity

Adopt strategies like SOAP message compression or selective querying to fetch only the necessary data. This helps to slim down the payload size over the network.

Server Output

Take advantage of kSOAP2's ability to cherry-pick the needed information from the response. This approach bestows some control over the server's XML output without the need to process the whole payload.

Efficient SOAP Communication

Make sure to implement asynchronous calls to shield your UI from blocking. Using Android's AsyncTask can help you align with Android's guidelines for background operations.

Taking care of additional considerations

Robust error handling

Incorporate robust try-catch blocks to handle various exceptions like SocketTimeoutException or XmlPullParserException, which, just like Monday mornings, can pop up unexpectedly during SOAP communication.

Threading

SOAP calls should be handled on a separate thread from the UI to ensure a smooth user experience- just like you'd prefer different queues for coffee and freshly baked muffins. Main thread operations can lead to an Application Not Responding (ANR) dialog.

Security Implications

Employ stringent security measures like WS-Security for encrypting and signing your SOAP messages. Especially crucial when exchanging sensitive data- nobody likes intruders.