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: Model View Controller, Java Platform Enterprise Edition (J2EE), Back-End Web Development, Server Side, Data Access, Apache Tomcat, Application Servers, Relational Databases, Databases, Java, Web Servers, SQL, Authentications, Web Applications, Secure Coding, Software Design Patterns, Data Persistence, Context Management
Intermediate · Course · 1 - 3 Months

Skills you'll gain: Frontend Performance, React.js, Web Development Tools, User Interface (UI)
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Object Oriented Design, Software Design Patterns, Functional Design, Maintainability
Intermediate · Course · 3 - 6 Months

Skills you'll gain: Object Oriented Programming (OOP), Software Documentation, Java Programming, Java, Computer Programming, Programming Principles, Computational Thinking, Computer Science
Intermediate · Course · 1 - 4 Weeks

LearnQuest
Skills you'll gain: Java Programming, Java, Object Oriented Programming (OOP), Object Oriented Design, Software Design
Intermediate · Course · 1 - 3 Months

LearnQuest
Skills you'll gain: Object-Relational Mapping, Java Platform Enterprise Edition (J2EE), Data Access, Data Persistence, Java, Relational Databases, Data Mapping, JUnit, Databases, Query Languages, Enterprise Application Management
Intermediate · Course · 1 - 4 Weeks
Skills you'll gain: OS Process Management, Operating Systems, System Programming, Performance Tuning, C (Programming Language), Data Structures, Debugging
Advanced · Course · 1 - 4 Weeks

Skills you'll gain: Apache Kafka, Spring Boot, Real Time Data, Java, Unit Testing, Restful API, JSON, Integration Testing, Data Transformation, Scalability, Debugging
Intermediate · Course · 3 - 6 Months

Skills you'll gain: Java Programming, Development Environment, Java, Integrated Development Environments, Encryption, Cryptography, Virtualization and Virtual Machines, Performance Tuning, Application Programming Interface (API), Object Oriented Programming (OOP), Scalability
Intermediate · Course · 1 - 3 Months

Skills you'll gain: Java Platform Enterprise Edition (J2EE), Object-Relational Mapping, Java, Application Servers, Middleware, Application Deployment, Data Persistence, Event-Driven Programming, Enterprise Application Management, Server Side, Context Management, Business Logic
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Java Programming, Functional Design, Performance Tuning, Application Programming Interface (API)
Intermediate · Course · 1 - 4 Weeks