Core Java courses can help you learn object-oriented programming, exception handling, multithreading, and Java Collections. 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.

LearnQuest
Skills you'll gain: Java Programming, Java, Object Oriented Programming (OOP), Computer Programming, Object Oriented Design, Development Environment, Programming Principles, Data Structures
Intermediate · Course · 1 - 4 Weeks

Peking University
Skills you'll gain: Java Programming, Java, Object Oriented Programming (OOP), Object Oriented Design, Computer Programming, C and C++, JUnit, Programming Principles, Network Model, UI Components, Software Design Patterns, User Interface (UI), Data Access, Data Structures, Application Development, File I/O, Event-Driven Programming, Maintainability, Software Development Tools
Intermediate · Course · 1 - 3 Months

EDUCBA
Skills you'll gain: Object Oriented Programming (OOP), Java Programming, Java, Object Oriented Design, File I/O, Application Development, Data Access, Systems Development, Computer Programming, User Interface (UI), Application Design, UI Components, Program Development, Programming Principles, Database Application, Database Management, Databases, System Design and Implementation, Event-Driven Programming, Integrated Development Environments
Beginner · Course · 1 - 3 Months

Skills you'll gain: Java Programming, Development Environment, Java, Integrated Development Environments, Key Management, Software Development Tools, Cryptographic Protocols, Encryption, Cryptography, Performance Tuning, Memory Management, Scalability, Software Installation
Intermediate · Course · 1 - 3 Months

Board Infinity
Skills you'll gain: Java Platform Enterprise Edition (J2EE), Application Performance Management, Software Design Patterns, Java, Enterprise Architecture, Java Programming, Enterprise Application Management, Secure Coding, Software Design, Model View Controller, System Monitoring, Security Controls, Software Architecture, Application Security, Maintainability, Application Frameworks, Programming Principles, Authorization (Computing), Authentications, Program Development
Intermediate · Course · 1 - 4 Weeks

Skills you'll gain: Selenium (Software), Ajax, Java Programming, Test Script Development, Java, Software Testing, Test Automation, Scripting, Automation, Cascading Style Sheets (CSS)
Intermediate · Course · 3 - 6 Months

Skills you'll gain: Spring Framework, JUnit, Restful API, Spring Boot, Unit Testing, Java Programming, Java, Hibernate (Java), Model View Controller, Java Platform Enterprise Edition (J2EE), Web Services, Object-Relational Mapping, Software Testing, Test Script Development, Apache Maven, Data Access, Databases, Database Management, Web Applications, Gradle
Beginner · Course · 3 - 6 Months

Skills you'll gain: Selenium (Software), Java, Java Programming, File I/O, File Management, Cascading Style Sheets (CSS), Extensible Markup Language (XML), Test Automation, Extensible Languages and XML, Test Script Development, Web Scraping, Apache, Web Development Tools, Data Import/Export, Verification And Validation, HTML and CSS, Hypertext Markup Language (HTML)
Intermediate · Course · 1 - 3 Months

Skills you'll gain: Java Programming, Java, Performance Tuning, System Programming, Code Reusability, Application Performance Management, Algorithms, JUnit, OS Process Management, Application Frameworks, Frontend Performance, Frontend Integration, Programming Principles, Spring Boot
Beginner · Course · 1 - 3 Months

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

Board Infinity
Skills you'll gain: Classification Algorithms, Java Programming, Data Preprocessing, Machine Learning Software, Model Training, Model Deployment, Model Evaluation, Decision Tree Learning, Logistic Regression
Beginner · Course · 1 - 4 Weeks

LearnQuest
Skills you'll gain: Spring Framework, JUnit, Application Frameworks, Unit Testing, Java Programming, Enterprise Application Management, Integration Testing, Configuration Management, Development Environment, Extensible Markup Language (XML), Context Management
Intermediate · Course · 1 - 4 Weeks