Tutorialspoint Design Patterns in Java Tutorial
https://www.tutorialspoint.com/design_pattern/index.htm
Javatpoint Design Patterns in Java Tutorial
https://www.javatpoint.com/design-patterns-in-java
DZone Design Patterns for Begineers with Java Examples
https://dzone.com/articles/design-patterns-for-beginners-with-java-examples
HowToDoInJava Design Patterns Tutorials
https://howtodoinjava.com/design-patterns/
W3spoint Java Design Patterns
https://www.w3spoint.com/java-design-patterns-tutorial-with-examples
SourceMaking Design Patterns
https://sourcemaking.com/design_patterns