All the questions I was asked on my job interview (within the past few weeks), first Java job. First phone interview: Interviewer: Do you know what a platform is? Me: Platform? In what context? I'm sorry, I know what the word platform means, but in what context ... Interviewer: As in, you know that there are hardware platforms and software platforms and that Java is a software platform. Me: (A bit stunned.) Yes, I know that Java is a software platform and not hardware. I: What is the difference between the JVM and the JRE? M: The JVM is the Java Virtual Machine, it converts the code we write to bytecode the computer can run and the JRE is the ... well, the JRE is the Java Runtime Environment and it... Hmmm. I can't quite remember what the JRE does specifically. Let me think. There's the JDK, the JRE, the JVM. The JDK has the ... I: That's fine. Don't worry. That's fine. Do you know what the classloader is and what it does? M: No. We used classes in school. We used interfaces, classes, and inheritance in the parent classes to child classes configuration, but I'm not sure what the classloader does. I can look that up for you and get back ... I: No, no. That's fine. Someone will call you tomorrow. They'll ask you some more basic questions. Me: Great. Thanks. Second phone call. Interviewer: Is Java pass-by-reference or pass-by-value? Me: Java is pass-by-value. If you send a primitive into a method and change that primitive inside that method it will not change outside that method unless you return it. Interviewer: Is that the same for objects? Me: That's not the same for objects. This is where it gets a little tricky. If you send in, say, an ArrayList into a method and add an entry into that ArrayList it will be added to that object outside the method. An object such as an ArrayList has a structure of items in it ... Interviewer: That's fine. That's fine. What if I have an ArrayList A. And I make a second ArrayList --let's say ArrayList B. Now I assign ArrayList B as ArrayList A like "ArrayList B = ArrayList A". What happens if I change ArrayList B? Me: ArrayList A will also change. Because when you assign ArrayList B with an "=" sign it's really just pointing to that object (ArrayList A) on the heap. They're the same thing. Interviewer: All right. Come in Monday for an interview. In-person interview. Interviewer: On the whiteboard can you map out some inherited classes, let's say, using animals. Start with animal and work down to ... dogs. Me: I just drew some boxes marked "Animals," "Mammals," "Canines," and "Dogs". I was super awkward and nervous and didn't really know what he wanted. Interviewer: Okay, where would ... say wolves be in here? Me: I just drew a line over from "Canines" and made another box marked "Wolves." Interviewer: Okay, now do wolves and dogs have the same attributes and actions? Me: They can. Yes. Or you can override the functions of each so that they're different. Interviewer: Okay, would "Animals" be a class or an interface in this instance? Me: I don't rightly know. I guess that's an architecture decision. I'm going to go out on a limb here and say it's a class. Interviewer: No, it's an interface. (We all laugh.) Me: All right. I blew that one. Interviewer: No, you're right, this is too abstract an example to say whether it's definitively one way or another. I mean, these are just boxes of animals on a whiteboard. But, we use interfaces here a lot. Our motto is "If it's not an interface, make it an interface. If you can't make it an interface, stop and get someone else to look at it. Then make it an interface." Me: Well, I'm a very junior developer. This will be my very first job. I'll rely on the team for much of the design aspect. Interviewer: All right. Thanks for coming in. Because I had gotten so many things wrong, I kinda thought I blew the interview. But they called a couple days later and said that I did really well and that they'd send me an offer by the end of the week. Anyway, these are all the job interview questions I got on my first Java job interview which was just a few weeks ago. Good luck. More on reddit.com

If this is for a junior positition, honestly just make it clear that you are very willing to learn. Motivated people that want to learn are way more valuable than someone with some more experience who doesn't. Regarding questions, in my first job interview they asked me about dependency injection, why letting spring control your beans (services,..) was good, some questions about transactions,.. Regarding java, the basics were asked (access modifiers, immutability, some stuff about OO approach; inheritance/polymorphism,...) Honestly if you do OK in the technical interview and make sure you are enthousiastic, you'll be fine. A major plus for me is when people ask questions and not just answer mine. If you don't know something, just be honest about it. A good hiring team will appreciate honesty a lot. Good luck! More on reddit.com

You can’t. There are so many topics and everyone asks different questions. Some just want to know some concepts others want you to code.

So relax and see what will happen.

Good luck

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I would add the application- contexts, bean factories, Environments/profiles, xml config, java config. Be prepared to choose one config type and talk about how you wire it up and add/remove/override properties. The spring- boot- starter basics and the changes to the POM required to make a project a spring project. What kind of decisions spring boot makes when it sees certain jars in a classpath Annotations for all the major things,configuration, components, requests, values, profiles, propertyscans Scope -singleton/prototype view/dispatcher/handler Spring Cloud setup logging and trouble shooting various things ie...startup failures, port conflicts, JPA/ Spring JDBC, Rest over a DB Webclient vs rest template perhaps new changes in boot 3/ spring 6 -- features More on reddit.com