Codio
Skills you'll gain: Apache Maven, JSON, JUnit, Java Programming, Java, Restful API, Integrated Development Environments, Programming Principles, Data Structures, Object Oriented Programming (OOP), Network Protocols, Unit Testing, Style Guides
Intermediate · Course · 1 - 4 Weeks

EDUCBA
Skills you'll gain: Ajax, Web Design, Java Platform Enterprise Edition (J2EE), Cascading Style Sheets (CSS), Web Applications, Scripting, Javascript and jQuery, Web Development, Java, Hypertext Markup Language (HTML), Middleware, Model View Controller, Hibernate (Java), Service Oriented Architecture
Intermediate · Course · 1 - 3 Months

Skills you'll gain: Integration Testing, Command-Line Interface, Application Deployment, Dependency Analysis, Data Migration
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Spring Framework, Web Applications, Java Platform Enterprise Edition (J2EE), Java, Authentications, Application Development, Software Design, Database Design, Model View Controller, Databases, Object Oriented Programming (OOP), Hypertext Markup Language (HTML)
Mixed · Course · 1 - 4 Weeks

Skills you'll gain: Application Programming Interface (API)
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Object Oriented Programming (OOP), Object Oriented Design, Java Programming, Java, Computer Programming, Data Validation, Data Integrity, Computer Science
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Distributed Computing, Java, Middleware, NoSQL, Event-Driven Programming, Databases, Software Architecture, Servers, Web Services, Microservices, Scalability, Transaction Processing
Intermediate · Course · 1 - 3 Months

Board Infinity
Skills you'll gain: Classification Algorithms, Data Preprocessing, Model Deployment, Model Evaluation, Decision Tree Learning, Regression Analysis, Logistic Regression
Beginner · Course · 1 - 4 Weeks

Skills you'll gain: Java Programming, Java, Object Oriented Programming (OOP), Object Oriented Design, Eclipse (Software), Computer Programming, Development Environment, Integrated Development Environments, Data Structures, Software Installation
Beginner · Course · 1 - 3 Months

Skills you'll gain: Programming Principles, Java, Data Structures, Program Development, Eclipse (Software), Object Oriented Programming (OOP), Computer Programming, Debugging, Application Programming Interface (API), Database Application
Intermediate · Course · 1 - 4 Weeks

LearnQuest
Skills you'll gain: Spring Framework, JUnit, Unit Testing, Enterprise Application Management, Java, Integration Testing, Configuration Management, Software Design Patterns, Extensible Markup Language (XML), Context Management, Dependency Analysis
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: JUnit, Spring Framework, Spring Boot, Java, Apache Maven, Hibernate (Java), Unit Testing, Gradle, Microservices, Object-Relational Mapping, Software Testing, Testability, Restful API
Intermediate · Course · 1 - 3 Months