Spring Boot
Spring Web MVC
Spring Data JPA
Spring Data JDBC
Spring REST
Spring WebFlux

Thymeleaf

Java SE
Java EE

JavaServer Pages (JSP)
JavaServer Faces (JSF)
Facelets
Expression Language (EL)
Swing

PrimeFaces
RichFaces
OmniFaces
ICEfaces

JDBC
Hibernate
jOOQ

JAX-RS
Jersey

Apache Maven
Gradle

Apache POI
Apache Log4J
Apache Commons CSV
Apache Commons IO
Apache Commons Validator
Apache Commons Lang

Selenium
JSoup
HtmlCleaner
HtmlUnit

Jackson
Google Gson
JSON-Java (org.json)

OkHttp
Unirest

Apache Tomcat
GlassFish

JUnit
Mockito