A beginner friendly material to start with. These resources can be used as training material for freshers.

1. Data Types and Variables - https://www.baeldung.com/java-primitives
2. Access Modifiers - https://www.baeldung.com/java-access-modifiers
3. If-Else
4. https://www.baeldung.com/java-control-structures
5. https://www.baeldung.com/java-using-not-in-if-conditions
6. Switch Case - https://www.baeldung.com/java-switch
7. Loops - https://www.baeldung.com/java-loops
8. OOP Concepts - https://www.baeldung.com/java-oop

• 1.1 : Concrete Class, Abstract Class, Interface

1. https://www.baeldung.com/java-concrete-class
2. https://java2blog.com/difference-between-abstract-class-and-interface-in-java/

• 1.2 : Static, Final

1. https://www.baeldung.com/java-static
2. https://java2blog.com/final-keyword-java-example/
3. https://java2blog.com/static-block-java/
4. https://java2blog.com/java-static-import-example/

• 1.3 : Method Overloading and Overriding

1. https://www.baeldung.com/java-method-overload-override

1. https://www.baeldung.com/java-wrapper-classes

1. https://www.baeldung.com/a-guide-to-java-enums

1. https://www.baeldung.com/java-type-casting

https://www.baeldung.com/java-pojo-class

1. https://java2blog.com/core-java-tutorial-for-beginners-experienced/#Chapter_11_String_Handling

1. https://java2blog.com/exception-handling-java/
2. https://java2blog.com/can-we-have-try-without-catch-block-in-java/
3. https://java2blog.com/difference-between-throw-and-throws-in-java/
4. https://java2blog.com/how-to-create-custom-exception-in-java/
5. https://java2blog.com/difference-between-checked-and-unchecked-exception-in-java/
6. https://www.baeldung.com/java-try-with-resources (Introduced in Java 7)

1. https://www.baeldung.com/java-collections
2. LinkedList - https://www.baeldung.com/java-linkedlist
3. ArrayList - https://www.baeldung.com/java-arraylist
4. Immutable ArrayList - https://www.baeldung.com/java-immutable-list
5. TreeSet - https://www.baeldung.com/java-tree-set
6. HashSet - https://www.baeldung.com/java-tree-set
7. HashMap - https://www.baeldung.com/java-hashmap
8. https://www.baeldung.com/java-collections-complexity
9. https://springframework.guru/sorting-java-collections/

1. https://www.baeldung.com/java-streams
2. Java 8 Streams - https://www.baeldung.com/java-8-streams
3. Functional Interfaces in Java - https://www.baeldung.com/java-8-functional-interfaces
4. Lambda Expressions - https://www.baeldung.com/java-8-lambda-expressions-tips
5. Java Stream Filter Lambda - https://www.baeldung.com/java-stream-filter-lambda
6. Sort Lambda - https://www.baeldung.com/java-8-sort-lambda
7. https://www.youtube.com/watch?v=gpIUfj3KaOc&list=PLqq-6Pq4lTTa9YGfyhyW2CqdtW9RtY-I3 (Java Brains Video Course Youtube (2016))

1. https://www.baeldung.com/java-optional

1. https://www.baeldung.com/java-generics

1. https://www.baeldung.com/java-inheritance-composition

1. https://www.baeldung.com/java-string-pool

1. https://www.baeldung.com/java-replace-if-statements

1. https://www.baeldung.com/java-dependency-inversion-principle

• Java 8 Features: https://www.javacodegeeks.com/java-8-features-tutorial.html
• Java 9 Features: https://www.baeldung.com/new-java-9
• Java 10 Features: https://www.baeldung.com/java-10-overview
• Java 11 Features: https://www.baeldung.com/java-11-new-features
• Java 12 Features: https://www.baeldung.com/java-12-new-features
• Java 13 Features: https://www.baeldung.com/java-13-new-features
• Java 14 Features: https://www.baeldung.com/java-14-new-features
• Java 15 Features: https://www.baeldung.com/java-15-new
• Java 16 Features: https://blogs.oracle.com/java-platform-group/the-arrival-of-java-16
• Java 17 Features: https://www.techgeeknext.com/java/java17-features (September 2021)

1. Maven - Video Tutorial (Java Brains) : https://www.youtube.com/watch?v=al7bRZzz4oU&list=PL92E89440B7BFD0F6&index=1&ab_channel=JavaBrainsJavaBrainsVerified
2. Gradle - Video Tutorial (Linkedin Learning) : https://www.linkedin.com/learning/gradle-for-java-developers

• What is apache tomcat? : https://www.youtube.com/watch?v=kkQOm02kep0&ab_channel=KKJavaTutorialsKKJavaTutorials
• What is Servlet? : https://www.javatpoint.com/servlet-tutorial
• Lifecycle of a Servlet : https://www.javatpoint.com/life-cycle-of-a-servlet
• How Servlet Works? : https://www.javatpoint.com/how-servlet-works
• Servlet Context : https://www.javatpoint.com/servletcontext
• Servlet Filter : https://www.javatpoint.com/servlet-filter
• What is war file? : https://www.javatpoint.com/war-file
• Introduction to Servlet : Video Tutorial - https://www.youtube.com/watch?v=7TOmdDJc14s
• Intro to servets - https://www.baeldung.com/intro-to-servlets
• Oracle Servlet Documentation : https://docs.oracle.com/javaee/6/tutorial/doc/bnafd.html
• Servlet MVC : https://www.baeldung.com/mvc-servlet-jsp

• What is dependency Injection : https://www.youtube.com/watch?v=GB8k2-Egfv0&list=PLC97BDEFDCDD169D7&ab_channel=JavaBrainsJavaBrainsVerified
• Dependency Inversion and Injection : https://www.baeldung.com/inversion-control-and-dependency-injection-in-spring
• Spring vs Spring Boot : https://www.baeldung.com/spring-vs-spring-boot
• Spring Boot : https://spring.io/guides/gs/spring-boot/
• Basic Spring Boot Course (Java Brains) : https://www.youtube.com/watch?v=YXlSkWq04jk&list=PLqq-6Pq4lTTbx8p2oCgcAQGQyqN8XeA1x&index=4&ab_channel=JavaBrainsJavaBrainsVerified
• Spring MVC : https://docs.spring.io/spring-framework/docs/3.2.x/spring-framework-reference/html/mvc.html
• Spring Quick Start Project : https://spring.io/quickstart
• Guide to Spring MVC : https://spring.io/guides/gs/serving-web-content/
• Restful Service with Spring : https://spring.io/guides/gs/rest-service/
• Core concepts of Spring (Optional) :
• https://www.springbyexample.org/examples/core-concepts.html
• https://www.springbyexample.org/examples/core-concepts-dependency-injection-to-the-rescue.html
• https://docs.spring.io/spring/docs/3.2.x/spring-framework-reference/html/mvc.html#mvc-servlet
• Java Jdbc : https://www.javatpoint.com/java-jdbc
• Spring Jdbc : https://www.baeldung.com/spring-jdbc-jdbctemplate
• Spring Data :
• JPA : https://www.javatpoint.com/jpa-tutorial (all topics)
• https://www.baeldung.com/the-persistence-layer-with-spring-data-jpa
• https://spring.io/guides/gs/accessing-data-jpa/
• Jackson Object Mapper : https://www.baeldung.com/jackson-object-mapper-tutorial
• Spring Security : https://www.youtube.com/watch?v=sm-8qfMWEV8&list=PLqq-6Pq4lTTYTEooakHchTGglSvkZAjnE&ab_channel=LinuxTexLinuxTex (*)
• Form Submission :
• https://spring.io/guides/gs/handling-form-submission/
• https://spring.io/guides/gs/validating-form-input/
• Java Front Controller Pattern : https://www.baeldung.com/java-front-controller-pattern
• Spring Core Annotations : https://www.baeldung.com/spring-core-annotations
• Spring MVC Annotations : https://www.baeldung.com/spring-mvc-annotations
• Spring Boot Annotations : https://www.baeldung.com/spring-boot-annotations
• Spring Data Annotations : https://www.baeldung.com/spring-data-annotations
• Spring Bean Annotations : https://www.baeldung.com/spring-bean-annotations

https://www.baeldung.com/thymeleaf-in-spring-mvc

• https://www.baeldung.com/start-here
• A quick migration guide from C++ to Java.