41.What are the features of UDDI?

Following are the features of UDDI −

• UDDI is a specification for a distributed registry of web services.
• UDDI is platform independent, open framework.
• UDDI can communicate via SOAP, CORBA, and Java RMI Protocol.
• UDDI uses WSDL to describe interfaces to web services.
• UDDI is seen with SOAP and WSDL as one of the three foundation standards of web services.
• UDDI is an open industry initiative enabling businesses to discover each other and define how they interact over the Internet.

42.What are the primary security issues with web services?

There are three specific security issues with web services −

• Confidentiality
• Authentication
• Network Security

43.Which component of Web service describes interfaces to web services?

UDDI describes interfaces to web services.

44.Which language UDDI uses?

WSDL is the language that UDDI uses.

45.Is XML-RPC is platform-dependent?

No! XML-RPC is platform-independent.

46.If a client sends an XML request to a server, can we ensure that the communication remains confidential?

Yes! As XML-RPC and SOAP run primarily on top of HTTP and HTTP has support for Secure Socketes Layer SSL. Communication can be encrypted via SSL.

47.If a client connects to a web service, how do we identify the user? Is the user authorized to use the service?

The following options can be considered but there is no clear consensus on a strong authentication scheme.
HTTP includes built-in support for Basic and Digest authentication, and services can therefore be protected in much the same manner as HTML documents are currently protected.
SOAP Digital Signature SOAP − DSIG leverages public key cryptography to digitally sign SOAP messages. It enables the client or server to validate the identity of the other party. Check it at http://www.w3.org/TR/SOAP-dsig.
The Organization for the Advancement of Structured Information Standards OASIS is working on the Security Assertion Markup Language SAML.

48.What do you mean by Web services manageability?

Web services manageability is defined as a set of capabilities for discovering the existence, availability, health, performance, usage, as well as the control and configuration of a web service within the web services architecture. As web services become pervasive and critical to business operations, the task of managing and implementing them is imperative to the success of business operations.

49.How to handle Network security threats in Web services?

There are two possible solutions −

• Filter out all HTTP POST requests that set their content type to text/xml.
• Another alternative is to filter the SOAPAction HTTP header attribute.

50.What are web services ?

Main characteristics of the Web Services are :

• Interoperability
• Extensibility
• Machine processable descriptions.

51.What is the difference between SOA and a web service?

SOA (Service-Oriented Architecture) is an architectural pattern that makes possible for services to interact with one another independently.
Web Services is a realization of SOA concept, that leverages XML, JSON, etc. and common Internet protocols such as HTTP(S), SMTP, etc. SOA is a system-level architectural style that tries to expose business. WOA is an interface-level architectural style that focuses on the means by which these service capabilities are exposed to consumers.

52.What is REST?

REST (REpresentational State Transfer) is an architectural style by which data can be transmitted over transport protocol such as HTTP(S).

53.What is the difference between a REST web service and a SOAP web service?

Below are the main differences between REST and SOAP web service

• REST supports different formats like text, JSON and XML; SOAP only supports XML;
• REST works only over HTTP(S) on a transport layer; SOAP can be used different protocols on a transport layer;
• REST works with resources, each unique URL is some representation of a resource; SOAP works with operations, which implement some business logic through different interfaces;
• SOAP based reads can’t be cached, for SOAP need to provide caching; REST based reads can be cached;
• SOAP supports SSL security and WS-security(Web Service-security); REST onlysupports SSL security;
• SOAP supports ACID (Atomicity, Consistency, Isolation, Durability); REST supports transactions, but it is neither ACID compliant nor can provide two phase commit.

54.How to decide which one of web service to use REST or SOAP?

“REST vs SOAP” we can rephrased to "Simplicity vs Standard". Of course, "Simplicity" with REST at most cases wins, it wins in performance, scalability and support for multiple data formats, but SOAP is favored where service requires comprehensive support for security (WS-security) and transactional safety (ACID).

55.What is JAX-WS?

JAX-WS (Java API for XML Web Services) is a set of APIs for creating web services in XML format.

56.What is JAXB?

JAXB (Java Architecture for XML Binding) is a Java standard that defines how Java objects are converted from and to XML. It makes reading and writing of XML via Java relatively easy.

57.Can we send soap messages with attachments?

Yes, we can send different formats such as PDF document, image or other binary file with soap messages as an attachment. Messages send using the binary data. SOAP messages is attached with MIME extensions that come in multipart/related.
An example:
MIME-Version: 1.0
Content-Type: Multipart/Related; boundary=MIME_boundary; type=text/xml;
start="<claim061400a.xml@ javahungry.com>"
Content-Description: This is the optional message description.
<?xml version='1.0' ?>
<SOAP-ENV:Envelope
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
<SOAP-ENV:Body>
..
<theSignedForm href="cid:claim061400a.tiff@javahungry.com"/>
..
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>
--MIME_boundary
Content-Type: image/tiff
Content-Transfer-Encoding: binary
Content-ID: ...binary TIFF image...
--MIME_boundary—

58.What is MTOM?

MTOM (Message Transmission Optimization Mechanism) is a mechanism for transmitting large binary attachments with SOAP messages as raw bytes, allowing for smaller messages.

59.What is XOP?

XOP (XML-binary Optimized Packaging) is a mechanism defined for the serializationof XML Information Sets that contain binary data, as well as deserialization back into the XML Information Set.