SOAP Interview Frequently Asked Questions and Answers

SOAP Interview Frequently Asked Questions and Answers

Define Web Service?

A web service is a kind of software that is accessible on the Internet. It makes use of the XML messaging system and offers an easy to understand, interface for the end users.

Define WSDL?

It means Web Services Description Language. It is basically the service description layer in the web service protocol stock. The Service Description layer describes the user interface to a web service.

Discuss various approaches to develop SOAP based web service?

We can develop SOAP based web service with two different types of approaches such as contract-first and contract-last. In the first approach, the contract is defined first and then the classes are derived from the contract while in the later one, the classes are defined first and then the contract is derived from these classes.

What are the types of information included in SOAP header?

Header of SOAP contains information like that,
1. In SOAP header client should handle authentication and transaction.
2. The SOAP message should process by client.
3. EncodingStyle is also has in header.

What is SOAP and how we can utilize this with Web components ?

SOAP is stands for Simple Object Access Protocol. SOAP was first comes in 1990 after that in 2000 it introduced to W3C.
In Web Component we use SOAP to send an request for to invoke programs on remote computers with using XML wrappers.
The main purpose to use SOAP in Web Service is that to send messages over HTTP protocol.

Element that we used in SOAP?

1. An envelope element is used to identifies and translates the XML document into a SOAP message.
2. A header element is used to contain header message.
3. A body is used to contain call and response message.
4. Fault element is used to communicate about the errors occurred during the process.

What are the disadvantages of SOAP?

1. It is much slower than middleware technologies.
2. Because we used HTTP for transporting messages and not use to defined ESB or WS-Addressing interaction of parties over a message is fixed.
3. Application protocol level is problematic because usability of HTTP for different purposes is not present.

What types of operations are available in WSDL?

There are four operations available:
1. One-way, where the operation can receive a message but will not return a response.
2. Request-response, where the operation can receive a request and will return a response.
3. Solicit-response, where the operation can send a request and will wait for a response.
4. Notification, where the operation can send a message but will not wait for a response.

What are transport methods in SOAP?

Different application running on different types of operating systems and using different technologies.
Example: To find company details, a SOAP request GetCompanyDetail() is sent to the server with the company id as the parameter. In response, details of company are returned via XML.

What are Transport methods in SOAP?

Application layer and transport layers of a network are used by SOAP. SMTP and HTTP are the valid application layer protocol uses as transport for SOAP. Wider acceptance is gained by HTTP, as it works better with the current internet infrastructure, especially with firewalls.

Give examples where SOAP is used.

Remote methods over multiple platforms and technologies are used with HTTP. SOAP is XML based protocol and platform-agnostic. Each application uses different technology. This may cause problems with proxy server and firewalls. SOAP is the solution for this situation.
Industries transport the request for finding best route and best cost price. So the application transfers a request to other similar services which uses SOAP.

Explain the role of XML in SOAP.

XML is used as the common format for data in cross platform applications. This file is used for representing message for communication. XML is mostly accepted standard for open source applications. XML format is more reliable format for Application Layer protocols for message transmission and negotiation.

What are SOAP Envelope element, SOAP actor element and SOAP body element?

Envelope Element: Envelope element contains header child and body child element.
Actor Element: Actor element specifies an entity by which an element is processed. It is referred as the ultimate recipient of the message, and used for assigning header entries to specific entities.
Body Element: Body element encloses the body entries of the message.

What do you mean by SOAP encoding?

XML format is used by SOAP for encoding data. It maps the high level data types into a serialized XML format known as Section 5 encoding (also known as SOAP encoding) and literal encoding. The other type of encoding named Literal encoding uses XML schema to validate information.

Why Encrypt SOAP messages?

The main purpose of SOAP is to exchange messages over HTTP. For communication it uses XML. The messages exchanged if done in plain text can be potentially viewed by anyone across the internet. SOAP over HTTPS is secured. The entire HTTP message, including both the headers and the body of the HTTP message is encrypted using public asymmetric encryption algorithms.