"The only way to learn a new programming language is by writing programs in it."
- OOP
- Exception Handling.
- Multithreading.
- Collections(List,Set,Map, ... )
- JDBC
- It is better to be familiar with java8 features stream and lambda expressions
- unit testing with JUnit
- maven
- Servlets
- JSP
- filters
- RESTful API (The Most popular With Spring)
- It is better to be familiar with SOAP Web Service
- Spring Core
- Spring Data
- spring AOP
- Spring Boot
- Spring RESTful API
- Spring MVC
- Spring Unit Test (test the service layer)
- Spring Security