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

Board Infinity
Skills you'll gain: Angular, HTML and CSS, Front-End Web Development, Javascript, Software Design Patterns, Web Components, Web Applications, Cascading Style Sheets (CSS), Web Development, TypeScript, Responsive Web Design
Intermediate · Course · 1 - 4 Weeks

Rice University
Skills you'll gain: Java Programming, Java, Data Structures, System Programming, Programming Principles, Debugging, Algorithms, Performance Testing
Intermediate · Course · 1 - 3 Months

Skills you'll gain: JUnit, Restful API, Software Design, JSON, Software Testing
Intermediate · Course · 3 - 6 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

Board Infinity
Skills you'll gain: Data Preprocessing, Model Deployment, Apache Mahout, Java, Java Programming, Apache Spark, Classification Algorithms, Applied Machine Learning, Deep Learning, Model Evaluation, Natural Language Processing, Data Cleansing, Machine Learning, Feature Engineering, Regression Analysis
Intermediate · Course · 1 - 4 Weeks

Coursera
Skills you'll gain: Data Preprocessing, Java, Data Structures, File I/O, Java Programming
Intermediate · Guided Project · Less Than 2 Hours

Johns Hopkins University
Skills you'll gain: Apache Hadoop, File Systems, Big Data, Data Infrastructure, Java, Data Structures, File Management, Systems Architecture, Data Processing, Distributed Computing, Data Storage, Development Environment, Scalability
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: File I/O, Data Import/Export, Java Programming, Java, Computer Programming, Data Structures, Object Oriented Programming (OOP), Integrated Development Environments, Computer Science
Beginner · Course · 1 - 4 Weeks

LearnQuest
Skills you'll gain: Spring Framework, Object-Relational Mapping, Transaction Processing, Data Persistence, Database Systems, Java, Restful API, Web Services, Web Applications
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Maintainability
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Object Oriented Programming (OOP), Java, Java Programming, Computer Programming, Programming Principles, Software Design, Data Structures, Debugging
Beginner · Course · 1 - 3 Months