LearnQuest
Skills you'll gain: Java Programming, Java, File I/O, Eclipse (Software), Object Oriented Programming (OOP), Object Oriented Design, Integrated Development Environments, Development Environment, Software Design, Computer Programming, Application Frameworks, Programming Principles, Virtual Machines, Web Development, Debugging, Data Persistence, Package and Software Management, Data Structures
Intermediate · Specialization · 3 - 6 Months

Skills you'll gain: Programming Principles, Data Import/Export, Integrated Development Environments, Debugging, File Management
Beginner · Course · 3 - 6 Months

LearnQuest
Skills you'll gain: Apache Maven, Spring Framework, Microservices, Java Platform Enterprise Edition (J2EE), Spring Boot, Java, Java Programming, Back-End Web Development, Software Architecture, Load Balancing, Application Servers, Restful API, Web Applications, Scalability
Advanced · Course · 1 - 4 Weeks

Amazon
Skills you'll gain: File I/O, Object Oriented Programming (OOP), Object Oriented Design, Java, Software Design, Maintainability, Debugging, Data Structures
Beginner · Course · 1 - 4 Weeks

LearnKartS
Skills you'll gain: JUnit, File I/O, Java Programming, Object Oriented Programming (OOP), Java, Unit Testing, Program Development, Maintainability, Software Development, Secure Coding, Software Testing, Programming Principles, Computer Programming, Test Case, Application Development, Authentications, Application Security, Application Design, Software Design Patterns, Debugging
Beginner · Specialization · 1 - 3 Months

Skills you'll gain: Kotlin, Android Development, Android Studio, Unit Testing, Object Oriented Programming (OOP), Mobile Development, Test Driven Development (TDD), Software Testing, Functional Design
Intermediate · Course · 1 - 4 Weeks
Multiple educators
Skills you'll gain: Unit Testing, Data Structures, Event-Driven Programming, File I/O, Interactive Data Visualization, Java, Java Programming, User Interface (UI), Object Oriented Programming (OOP), JUnit, Debugging, Object Oriented Design, Computer Programming, Cryptography, Software Engineering, Performance Tuning, Algorithms, Data Analysis, Software Design, Problem Solving
Beginner · Specialization · 3 - 6 Months

Skills you'll gain: Java Programming, Object Oriented Design, Virtual Machines, Linux Commands
Intermediate · Specialization · 1 - 3 Months

Duke University
Skills you'll gain: Debugging, Java, Algorithms, Java Programming, Program Development, Programming Principles, Statistical Analysis, Software Design, Computer Programming, Data Import/Export, Integrated Development Environments, File I/O, Data Processing, Software Documentation, Data Manipulation, Object Oriented Programming (OOP), API Design, Data Analysis, Software Testing, Problem Solving
Beginner · Course · 1 - 3 Months

Scrimba
Skills you'll gain: Ajax, Object Oriented Programming (OOP), Javascript, JSON, Application Programming Interface (API), Scripting, Software Design Patterns, Data Management, Data Structures, Event-Driven Programming, Data Validation, Prototyping, Computational Logic, Maintainability, Programming Principles, Web Development, Software Development, Debugging, Software Engineering, Performance Tuning
Intermediate · Specialization · 1 - 3 Months

Skills you'll gain: Responsive Web Design, User Interface (UI), Cascading Style Sheets (CSS), User Interface and User Experience (UI/UX) Design, Web Applications, Web Development, Front-End Web Development, HTML and CSS, Javascript, Real Time Data, Hypertext Markup Language (HTML), Application Programming Interface (API), Event-Driven Programming, Animations
Advanced · Course · 3 - 6 Months

Skills you'll gain: Hibernate (Java), Object-Relational Mapping, CI/CD, Spring Boot, Restful API, Java Programming, Integration Testing, Docker (Software), Database Development, Cloud Deployment, Application Security, Java, Containerization, SQL, Databases, MySQL, NoSQL, Kubernetes, Test Driven Development (TDD), Object Oriented Design
Beginner · Specialization · 1 - 3 Months