20 Apache CXF Interview Questions and Answers

Apache CXF is a web service framework that helps developers create and deploy web services. When applying for a position that involves web service development, it is likely that you will be asked questions about Apache CXF. Knowing how to answer these questions can help you make a positive impression on the hiring manager and improve your chances of being hired. In this article, we discuss the most commonly asked Apache CXF questions and provide sample answers to help you prepare for your interview.

Apache CXF Interview Questions and Answers

Here are 20 commonly asked Apache CXF interview questions and answers to prepare you for your interview:

1. What is Apache CXF?

Apache CXF is an open source services framework. CXF helps you build and develop services using frontend programming APIs, like JAX-WS and JAX-RS. These services can then be deployed on a variety of transport layers, including HTTP, JMS, and Web services.

2. Can you explain the advantages of using Apache CXF?

Apache CXF is a popular open source framework for developing web services. Some of the advantages of using CXF include its ease of use, flexibility, and support for a wide range of web service standards.

3. How do you create web services with Apache CXF?

There are a few different ways to create web services with Apache CXF. One way is to use the JAX-WS API, which is a standard Java API for creating web services. Another way is to use the CXF specific APIs, which give you more control over the details of the web service. Finally, you can also use the CXF Simple Frontend, which is a simpler way to create web services that is geared towards those who are new to web services development.

4. What are some examples of projects that use Apache CXF?

Apache CXF is an open source services framework. A few examples of projects that use CXF are:

– Apache ServiceMix
– Apache Camel
– Red Hat Fuse
– Talend ESB

5. Do I need any third party libraries to run Apache CXF? If yes, then which ones and why?

No, you do not need any third party libraries to run Apache CXF. All of the libraries that Apache CXF needs are included in the distribution.

6. Can you give me an example of how a JAX-WS service can be exposed using Apache CXF?

Yes. A JAX-WS service can be exposed using Apache CXF by creating a class that extends org.apache.cxf.jaxws.JaxWsServerFactoryBean and configuring it with the appropriate service class and address.

7. Is it possible to expose a non-annotated POJO as a Web Service in Apache CXF? If yes, then how?

Yes, it is possible to expose a non-annotated POJO as a Web Service in Apache CXF. You will need to create a Service class and annotate it with the @WebService annotation. Then, you will need to create an endpoint class that extends the AbstractJaxWsServiceFactoryBean class. In this endpoint class, you will need to override the createServiceDelegate() method and return an instance of your POJO.

8. How do you generate Java artifacts from WSDL files in Apache CXF?

In Apache CXF, you can use the wsdl2java tool to generate Java artifacts from WSDL files. This tool will take a WSDL file and generate the necessary Java classes that can be used to access the services described in the WSDL file.

9. How can you set up security for web services in Apache CXF?

There are a few different ways to set up security for web services in Apache CXF. One way is to use a JAAS LoginModule. Another way is to use a WS-SecurityPolicy.

10. What are interceptors in Apache CXF?

Interceptors are a key part of the Apache CXF framework, providing a way for developers to add custom functionality at key points in the processing of a message. There are a number of different types of interceptors, each with its own specific purpose. For example, there are interceptors that can be used to log incoming and outgoing messages, or to add security headers to messages.

11. Is there any way to configure logging in Apache CXF? If so, then how?

Yes, you can configure logging in Apache CXF. You can do this by setting the logging category for org.apache.cxf to the desired level. For example, you could set it to DEBUG to get debug-level logging output.

12. How does Apache CXF help support contract first development?

Apache CXF helps support contract first development by providing tools that can generate WSDL files from Java code. This allows developers to start with the WSDL file and then generate the Java code that will implement the service. This can be helpful in ensuring that the service meets the requirements specified in the WSDL file.

13. How does Apache CXF handle concurrent requests?

Apache CXF uses a multi-threaded approach to handling concurrent requests. This means that each request is handled by a separate thread, and the threads are managed by a thread pool. This approach allows CXF to scale well and handle a large number of concurrent requests.

14. What are some ways to call a SOAP-based web service using Apache CXF?

There are a few ways to call a SOAP-based web service using Apache CXF. One way is to use the CXF Client API. This allows you to create a client object that can be used to make SOAP requests. Another way is to use the CXF JAX-WS API. This allows you to create a web service client that can be used to make SOAP requests.

15. How does Apache CXF compare to other popular frameworks like Spring or Jersey?

Apache CXF is a popular open source framework for developing web services. CXF offers a wide range of features, including support for multiple protocols and standards, a robust programming model, and easy integration with other frameworks. When compared to other frameworks, CXF provides more flexibility and customization options.

16. What’s your opinion on the performance of Apache CXF compared to its competitors?

I believe that Apache CXF is a very performant web service framework. I have used it in the past and it has always been able to handle the load that I have thrown at it.

17. What are the main differences between Apache CXF and Axis 2?

The main difference between Apache CXF and Axis 2 is that CXF is a much newer project, and thus benefits from a number of improvements in design and implementation. CXF also has a much more active community and is better supported than Axis 2.

18. Which version of Apache CXF should I use for my project?

The latest stable release is always the recommended version to use.

19. Why was Apache CXF created?

Apache CXF was created as a way to provide an open source implementation of the JAX-WS specification. JAX-WS is a set of Java APIs that allow for the creation of web services and web service clients. CXF aims to make it easy to create and deploy web services, as well as to integrate with existing applications.

20. What are some common problems encountered when using Apache CXF?

Some common problems that can be encountered when using Apache CXF include:
-Configuration errors
-Classloading issues
-Version compatibility issues
-Memory leaks