U should have good hold of ur Basic Java concepts and whatever u have written on ur CV. In 1st round they will check it. In 2nd round they will ask u to do coding for 2 questions and some other questions based on Collections and Multithreading. Some questions on Java 8 and Spring. 3rd round is Techno-Managerial: U will be be asked about deep concepts of Java like INTEGER POOLING and its limitations. Various technical scenarios will be given to u and u need to solve them within a time limit. This will generally be an average difficulty round.