Java courses can help you learn object-oriented programming, data structures, exception handling, and multithreading concepts. You can build skills in writing efficient algorithms, debugging code, and developing user interfaces. Many courses introduce tools like Eclipse and IntelliJ IDEA, which are commonly used for coding and testing Java applications, along with frameworks such as Spring and Hibernate that facilitate web development and database management.

University of Colorado Boulder
Skills you'll gain: Object Oriented Design, Object Oriented Programming (OOP), Unified Modeling Language, JUnit, Software Testing, Software Engineering, Java, Java Programming, Computer Programming, Unit Testing, Program Development, Software Design, Test Driven Development (TDD), Conceptual Design
Build toward a degree
Intermediate · Course · 1 - 3 Months

LearnQuest
Skills you'll gain: Restful API, Web Services, Java Platform Enterprise Edition (J2EE), Software Design, Java, Application Programming Interface (API), API Design, JSON, Web Applications, Software Architecture
Beginner · Course · 1 - 4 Weeks

Skills you'll gain: Google Cloud Platform, Cloud Deployment, YAML, Restful API, Load Balancing, Configuration Management
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: React.js, JavaScript Frameworks, Data Persistence, Javascript, Context Management, Web Development
Intermediate · Guided Project · Less Than 2 Hours

Skills you'll gain: API Testing, Cucumber (Software), Behavior-Driven Development, JSON, Restful API, Application Programming Interface (API), Test Tools, Test Case, JUnit, Security Testing, Test Script Development, Test Data, Test Automation, Apache Maven, Authentications, Development Environment, Authorization (Computing)
Mixed · Course · 1 - 4 Weeks

Scrimba
Skills you'll gain: TypeScript, Node.JS, Web Development Tools, React.js, Server Side, Javascript, Data Structures, Web Development, Data Validation, Web Design, Computer Programming
Intermediate · Course · 1 - 4 Weeks

Board Infinity
Skills you'll gain: Angular, Cascading Style Sheets (CSS), Front-End Web Development, HTML and CSS, Responsive Web Design, jQuery, React.js, Javascript, Web Applications, JavaScript Frameworks, Web Development, Web Components, Web Design and Development, Web Development Tools, UI Components, User Interface and User Experience (UI/UX) Design, Web Content Accessibility Guidelines, User Interface (UI), Event-Driven Programming, Maintainability
Beginner · Specialization · 1 - 3 Months

Skills you'll gain: Spring Boot, React.js, Object-Relational Mapping, Restful API, YAML, Data Access, Web Applications, Databases, Application Performance Management, Full-Stack Web Development, Configuration Management, Command-Line Interface
Intermediate · Course · 1 - 4 Weeks

Infosec
Skills you'll gain: Authentications, Cryptography, Application Security, Web Applications, Javascript, Identity and Access Management, Node.JS, Browser Compatibility
Intermediate · Course · 1 - 4 Weeks

Johns Hopkins University
Skills you'll gain: Javascript, Ajax, JSON, Web Applications, Web Development, Scripting, Hypertext Markup Language (HTML), Object Oriented Programming (OOP), Event-Driven Programming, Web Services, Programming Principles, Prototyping, Network Protocols
Mixed · Course · 1 - 4 Weeks

Board Infinity
Skills you'll gain: Angular, HTML and CSS, JavaScript Frameworks, Application Frameworks, Javascript, Hypertext Markup Language (HTML), Front-End Web Development, Scalability, Web Applications, Cascading Style Sheets (CSS), Web Development, Software Design, UI Components
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Version Control, Unity Engine, GitHub, Bitbucket, Git (Version Control System), Android Development, C# (Programming Language), Android (Operating System), Game Design, Mobile Development, Scripting, User Interface (UI), 3D Assets, Video Game Development, Animation and Game Design, User Interface (UI) Design, Computer Graphics, Application Development, Graphics Software, Animations
Beginner · Specialization · 3 - 6 Months