Top Java Web Services Interview Questions You Should Prepare
While preparing for your technical interview, it is critical to go over Java Web Services interview questions. Knowing what types of Java Web Services interview questions to expect and brushing up on fundamental Java concepts can help you ace the tech interview.
Java is a high-level, class-based, object-oriented programming language. Using Java Web Services, it can communicate and interact with PHP and.Net. Because Java can interface with various platforms, it can be utilized to create huge web applications. Java web development allows users to engage with the interface by creating dynamic web pages. As a result, Java Web Services interview questions play an important role in tech interviews for software engineers, software developers, and engineering managers.
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Here’s what we’ll cover in this article:
- Java Web Services Interview Questions and Answers
- Java SOAP Web Services Interview Questions and Answers
- Sample Java Web Services Questions for Practice
- FAQs on Java Web Services Interview Questions
Java Web Services Interview Questions and Answers
Listed below are Java Web Services interview questions and answers that you can refer to for a quick revision of vital concepts:
Q1. What is a Java Web Service? What are its types?
Generally, web services comprise applications that allow communication between devices over the internet. As web services use standardized XML for information exchange, they are usually independent of the languages and technologies in which the devices are built. XML stands for eXtensible Markup Language. Java web service is a method of communication between the client and server applications using HTTP over the World Wide Web through WSDL.
There are two primary types of Java Web Services:
- SOAP web services (Simple Object Access Protocol)
- RESTful web services (Representational State Transfer)
Q2. What are the components of web service?
It is one of the most popular Java Web Services interview questions that recruiters ask. The major web services components are:
- RDF: Resource Description Framework
- SOAP: Simple Object Access Protocol
- UDDI: Universal Description, Discovery, and Integration
- XML: Extensible Markup Language
- WSDL: Web Service Description Language
Q3. What does the term interoperability mean?
Many Java Web Services interview questions are about explaining certain terms.
In the context of web services, the term interoperability refers to the ability of systems to work in tandem without any special requirements. It is a fundamental characteristic of web services. It implies that communication, data sharing, and services amongst applications remain the same across different platforms.
Q4. What is a Web service protocol stack?
A web service protocol stack is a protocol stack that defines, locates, implements, and makes web services interact with one another. It is a stack of computer networking protocols.
Q5. What are the various layers of the Web service protocol stack?
Web service protocols form an integral part of Java Web Services interview questions in any tech interview. Therefore, you must not miss out on them when preparing sample Java Web Services interview questions.
There are four layers in the web service protocol stack. Every layer is associated with specific functions:
Service Transport: Service transport is first in the web service protocol stack. It transports XML messages to various client applications. The protocols used by the layer are:
- Block Extensible Exchange Protocol (BEEP)
- Hypertext Transport Protocol (HTTP)
- File Transfer Protocol (FTP)
- Simple Mail Transport Protocol (SMTP)
XML Messaging: The messages are encoded in the XML format in this layer. It consists of:
- Simple Object Access Protocol (SOAP)
Service Description: This layer comprises various XML messaging functions, locations, and data types. It includes the WSDL interface format.
Service Discovery: This layer helps publish and find devices and web services over the Web. It includes UDDI.
Q6. Explain UDDI with features
This is one of the most common Java Web Services interview questions for any tech interview. Ensure that the answer is precise and to the point.
UDDI stands for Universal Description Discovery and Integration. It is an XML-based standard under the service discovery layer of the web service protocol stack. It employs the use of Web Service Description Language (WSDL).
UDDI acts as a directory and helps in the registry for web services worldwide over the web.
The primary features of UDDI are:
- UDDI is platform-independent
- It is an open framework
- UDDI can communicate via SOAP, Java RMI Protocol, CORBA, and more
- UDDI uses Web Service Definition Language (WSDL) files
Q7. What do you understand about Web Service Architecture?
Applications require a set architecture that ensures whether the application is working as designed. Similarly, web service architecture comprises the operations between two different applications running on various platforms and frameworks. These are supported by a different standard called web service. The architecture of web service involves the interaction of three roles:
- Service requester
- Service provider
- Service registry
Java SOAP Web Service Interview Questions and Answers
Q1. What do you mean by SOAP? State any three advantages of SOAP.
SOAP or Simple Object Access Protocol is an XML-based protocol to access web services. It allows the interchange of data or information between two devices using request and XML-based protocols like HTTP, SMTP, and more.
The advantages of SOAP are:
- It is language and information independent.
- It offers web service security.
- It is easy to debug and eliminate firewall issues.
Q2. Briefly describe the different elements of the SOAP Document.
The SOAP message is an XML document consisting of three parts:
- SOAP Envelope is a mandatory packaging element that identifies XML documents as a SOAP message. It marks the beginning and the end of the message. Thus, the receiver knows that the entire message has been received.
- SOAP Header is an optional element that contains application-specific information.
- SOAP Body is another mandatory element containing call and response information. It contains XML data with the message that is being sent.
Q3. What do you understand about RESTful Services? Mention two advantages.
It is important to practice RESTful web services interview questions and answers in Java for tech interviews.
REST stands for Representational State Transfer. RESTful web services are used for producing loosely coupled applications over HTTP. The main advantages are:
- REST protocol separates the user interface from the data server and storage.
- REST web services are language-independent. They can be implemented using several languages like PHP, Python, and Java.
- It is a lightweight protocol. It enables information exchange with XML or JSON formats — image, text, XML formats.
Q4. Are there any advantages of using RESTful web services over SOAP web services?
This is also among Java’s most popular RESTful web services interview questions and answers.
Yes, there are multiple advantages of using RESTful services over SOAP, for instance:
- REST has increased speed and formatting flexibility in comparison to SOAP.
- REST is lightweight and has a smaller learning curve, while SOAP has security, addressing, and more standards.
Q5. Mention three primary security issues of Web Services.
This is one of the most common web service security interview questions in Java. You must briefly describe the security issues as well.
The three primary security issues of web services are:
- Confidentiality of the data by preventing the unauthorized disclosure of information.
- Network security such as data loss, malicious attacks, hacking, and security breaches.
- Authentication of a user when they have provided their security credentials.
Q6. What do you understand about EIS and EPS?
EIS stands for Entrust Identification Service. The Entrust Security platform generates EIS. It allows the corporates to handle and control the identities trusted to perform web service transactions.
EPS refers to Entrust Privacy Service, which deals with security and confidentiality by encrypting data. It ensures that only authorized parties can access the data.
Q7. Name some commonly implemented frameworks for Java Web Services.
The commonly implemented Java Web Services frameworks are:
- Apache Axis2
- Apache CXF
- Glassfish/Java Web Services Development Pack
- Web Services Interoperability Technology (WSIT)
- Web Services Interoperability Framework (WSIF)
Q8. What is XML-RPC? Mention a few features of XML-RPC.
XML-RPC is an XML-based protocol. It is simple and helps exchange information between two devices over a network. It is compatible with Perl, Java, Python, and C.
- XML Response is set in the HTTP response to pass information from a client computer to a server computer.
- XML is platform-independent.
Q9. What is Java API for XML Messaging (JAXM)?
JAXM is a SOAP-based standard to send XML documents from the Java platform over the internet. It can also work with higher-level messaging protocols. This can be done by adding the protocol’s functionality on top of the SOAP.
Q10. List the different JAVA packages in the JAXB binding framework
There are three JAVA packages in the JAXB binding framework:
- xml.bind package defines abstract classes and interfaces which can be used directly with content classes
- xml.bind.helper package provides a partial implementation for javax.xml.bind interfaces
- xml.bind.utilI package consists of utility classes that can be used by client applications to manage validation, marshaling, and unmarshalling events.
The applications that are already executing JAXB architecture cannot use these APIs.
Q11. What is JAX PACK?
Java API is for the XML pack. For different web services development, it integrates all the programming interfaces by SUN. JAX Pack is a bundle of JAXM, JAXB, JAX-RPC, and JAXR. It includes the documentation for support for the WSDL, XSLT, SAX, DOM.SOAP, EBXML, UDDI standards.
Sample Java Web Services Questions for Practice
Following are sample Java Web Services interview questions for coding interviews that you can practice.
- Discuss the working of Java Web Services.
- List the advantages of Java Web Services.
- What is a SOAP message?
- What are the important elements of Web Services Description Language?
- What do you mean by SOA in Java?
- List the tools to test the Java Web Services.
- What is loosely coupled architecture in Java Web Services?
- What are the different approaches to developing SOAP-based java web services?
- What are the primary security issues of Java Web Services?
- What are the components that are published while deploying a web service?
FAQs on Java Web Services Interview Questions
Q1. Why do we need Java Web Services?
Java web services allow applications to communicate and share data among themselves. For example, .Net can communicate to Java and vice versa. These web services allow the application and technology to work independently.
Q2. Is REST API a web service?
REST APIs are a form of Web Service API. A REST API is a Web Service API architecture approach that is standardized. The use of HTTP methods to make a network request is one of the requirements for being a REST API.
Q3. What is SOAP in web services?
SOAP is an XML-based communications technology for transmitting data between two computers over the internet. Because SOAP messages are entirely generated in XML, they are independent of platform and language. An Envelope that marks the message's start and end is included in a SOAP message.
Q4. Are Java Web Services interview questions asked at Java fresher interviews?
As a fresher, you are expected to know the primary applications of Java, and web services are one of them. Thus, Java Web Services interview questions are important for freshers and experienced developers.
Q5. What are the web services that Java has to offer?
The various web services that Java provides are REST web service, SOAP web service, JAX-WS, JAX-RS, and more.
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