my java backend road map

Java SE

OOP
Exception Handling.
Multithreading.
Collections(List,Set,Map, ... )
JDBC
It is better to be familir with #java8 features stream and lambda expressions
unit testing with JUnit
maven

Java EE

Servlets
JSP
filters

Hibernate

Web Service

RESTful API (The Most popular With Spring)
It is better to be familiar with SOAP Web Service

Spring

Spring Core
Spring Data
spring AOP
Spring Boot
Spring RESTful API
Spring MVC
Spring Unit Test (test the service layer)
Spring Security