EROAD

Java Technical Test

This test is in two parts.

Part one needs to be completed within an hour and sent back via email.

Part two is a practical coding test – this has a time frame of an hour and a half.  (We will send you Part two at an agreed time, once you have completed the first stage).

Part One – JAVA GENERAL
Please answer as many of the following questions as possible within 1 hour. Keep your answers brief. Your answers will be examined by a person, not a machine, with a focus on identifying the breadth of your knowledge. Do not struggle to provide perfect answers, or concern yourself with recalling exact UML notation. We are not testing your skills as a compiler or a drawing tool.


 	Java General
1. What is a transient variable?
2. Show a class that illustrates overloaded methods.
3. What is serialization?
4. What order should catch statements for FileNotFoundException and IOExcepton be written and why? Or does it not matter?
5. Given that class B extends A, and that A implements a method “doStuff()”, what would B's implementation of “doStuff()” look like if it needed to call A's implementation?
6. If you're overriding the method equals() of an object, which other method might you also consider?
7. What access level do you need to specify in the class declaration to ensure that only classes from the same package can access it?
8. What does it mean that a class or method is final?
9. Put down a few points on what ‘bad code’ means to you?

Database
1. You have a SQL query which is performing badly, what steps would you take to ascertain why?
2. What is a view?
3. Compare the two common locking approaches that are used by RDBMSs giving any advantages or disadvantages you can think of.


Patterns/UML
1. What is the chain of responsibility pattern?
2. List 3 classic Gang of Four design patterns.
3. A class 'Dog' is a subclass of 'Animal'. 'Dog' also implements a tagged interface 'Pet'. ‘Dog’ has four ‘Leg’s and  may also have ‘Flea’s. Draw a UML class diagram illustrating these relationships and classes: ‘Dog’, ‘Animal’, ‘Pet’, ‘Leg’, “Flea’.

HTML / XML / Web Services
1. What's special about a CDATA section?
2. What's the difference between HTTP GET and POST?
3. Name two different ways of parsing XML documents?
4. What is difference between a SOAP and REST web service?

J2EE
1. What does JNDI do?
2. In Spring what does a Controller class do?
3. In Spring how do you prevent a certain field in the model being updated?
4. What are the different kinds of enterprise beans, and what do they do?
5. What is the main advantage of local interfaces?
6. What are the different messaging models available in JMS?
7. What is an XA transaction?

Unix
1. How do you rename a file in Unix?
2. What command would you use to remove a directory and all the files beneath it?
3. How would you add execute permission to a script?
4. What command would you use to view what a process is writing to a log file.
5. How would you search for files suffixed with ".txt" in a given directory, and its subdirectories?