Using threads, write a program to print 1-100. (I used atomicInteger) PS- Remember to learn the import statements because imports you have to write yourself. ReEntrantLock. Is it a class or interface? Which class/interface it implements/extends. Have you heard of effectively immutable. Can concurrentHashmap store null key and null value? Working of concurrentHashMap. Suppose two thread try to read and write on the same segment/bucket of concurrentHashmap. Is it possible to happen parallely? Fail-safe v/s fail-fast. Hashmap internal bucket linkedlist or trees? What if I have an implementation where the hashCode of hashMap always returns 1 what will happen if I try to insert 10 data to this hashMap? CopyOnWriteArrayList. Is the iteration happen on copy or the original list. How does it perform? Liskov substitution principle. Difference in PUT and POST Convert an array of primitive int to it’s square and sort it. int a[]= {5,6,2,3,9} -> List<Integer> - {4,9,25,36,81} Convert an array of Integer to List. Now can you add any number to it? What is UnSupportedException? (java.lang.ClassCastException: java.util.Arrays$ArrayList cannot be cast to java.util.ArrayList - Stack Overflow) What is ExecutionException? Why completableFuture over ExecutorService? ForkJoinPool. What it implements? Is it class or interface? Where it is used? Transaction in microservices. Transaction in spring. How rollbacks happen? What is scope What is profiler? Can we extend throwable class? Docker command to create image. Kubernetes command to get pods. Arraylist default size. HappensBefore principle in Java. Is the read happen first or write in concurrentHashmap conflict. HTTPCode 4XX meaning, 5XX meaning (400,401,402,500) Have you optimized JVM? How garbage collector works? How the request flows from frontEnd to backend? Is there any buffer space in between? If the request is taking to long from server, How frontEnd handles this situation? How Kafka works? IS there any ordering in Kafka? What if