Interview Questions

WebService

Difference between SOAP & REST base web services

1.) SOAP relies exclusively on XML to provide messaging services.
2.) SOAP has some rigid set of messaging patterns than REST.
The rules in SOAP are important because without these rules,
you can’t achieve any level of standardization.
3.) SOAP is designed to support expansion, so it has all sorts of other acronyms and abbreviations associated with it, such as WS-Addressing, WS-Policy, WS-Security, WS-Federation, WS-ReliableMessaging, WS-Coordination, WS-AtomicTransaction, and WS-RemotePortlets.

Web Service Architecture

What is the format of SOAP message?

<SOAP-ENV:Envelope
    <SOAP-ENV:Header>
    …
    </SOAP-ENV:Header>

    </SOAP-ENV:Body>
    ….
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

What are the components of SOAP?

The various components of SOAP protocol are,

1. SOAP Envelope
It is the root element in the SOAP message. It has an optional Header element and a mandatory Body element.

2. SOAP Header
It is an optional element which is used to pass the application specific information like Authentication information etc.

3. SOAP Body
It is the mandatory element which carries the data between the Client and the Server machines.

4. SOAP Fault
This is used to carry the Error information in the SOAP message

How Web Services works?

In this let’s see how applications running in different platforms interact with each other using Web Services.

WS Server application:

What is WSDL?

WSDL stands for Web Service Description Language. WSDL describes the Web services (i.e., describes the list of methods defined in the Web service) and also locates the Web services

What is UDDI?

UDDI stands for Universal Description, Discovery and Integration.

It is directory service where companies can register their Web Services and can be used by others by looking in to the UDDI interface.

What is SOAP?

SOAP stands for Simple Object Access Protocol. It is an XML based protocol by which applications can exchange information in the form of XML over HTTP interface.

Web Services uses SOAP for sending and receiving the messages between different applications.

What is Web Service?

Web Service provides the standard for communication between different software applications that are running in different platform. For example, an application developed using the language “C++” in Windows can communicate with another application developed using “Java” in Linux.

By this way, any applications can communicate with other application provided they follow the standards defined by Web Service.