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.

Board Infinity
Skills you'll gain: React.js, Responsive Web Design, Front-End Web Development, Bootstrap (Front-End Framework), JavaScript Frameworks, UI Components, Programming Principles, Javascript, HTML and CSS, Web Applications, Event-Driven Programming, Web Development, User Interface (UI)
Intermediate · 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

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

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

LearnQuest
Skills you'll gain: JUnit, Unit Testing, Software Testing, Mockups, Test Case, Test Driven Development (TDD), Java
Intermediate · Course · 1 - 4 Weeks

Infosec
Skills you'll gain: Application Security, Serverless Computing, Secure Coding, Risk Management Framework, Threat Modeling, Cloud Security, Infrastructure Security, Cloud Services, Web Applications, Cloud Platforms, Javascript, Node.JS, Amazon Web Services
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: JSON, Javascript, Ajax, JavaScript Frameworks, Web Development Tools, Software Testing, Frontend Performance, Event-Driven Programming, Hypertext Markup Language (HTML), Web Servers, Data Validation, Data Structures
Beginner · Course · 1 - 3 Months

Scrimba
Skills you'll gain: JSON, Restful API, Web Applications, Application Programming Interface (API), Responsive Web Design, Cascading Style Sheets (CSS), Event-Driven Programming, HTML and CSS, Javascript, Back-End Web Development, Frontend Integration, Web Development, Web Services, Real Time Data, Web Development Tools, Game Design, Hypertext Markup Language (HTML), Servers, Software Development
Intermediate · Specialization · 1 - 4 Weeks

Skills you'll gain: Angular, Authorization (Computing), JavaScript Frameworks, Network Routing, Application Programming Interface (API), TypeScript, Javascript, Web Development
Advanced · Guided Project · Less Than 2 Hours

Microsoft
Skills you'll gain: Game Design, Software Development, Development Environment, Software Documentation, Data Validation, Javascript, Debugging, Maintainability, Data Structures, Software Design, Computer Programming, Data Management
Beginner · Course · 1 - 4 Weeks

Skills you'll gain: Angular, JavaScript Frameworks, Model View Controller, Javascript, Web Development Tools, Web Development, Software Development
Intermediate · Guided Project · Less Than 2 Hours

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