How to Java Documentation
Being able to navigate the Java documentation is very important. It contains a large amount of information and explanations on many libraries you will be using during the lecture. Knowing what functionality is offered by which library gives you an advantage when solving exercises.
Java Documentation Version
The Java documentation is one of the first results that will show up whenever you search for a Java class or method on the internet. Make sure however that the Java documentation is not outdated. You want to be using the version 19 or later.
How to Find Things
Use the search field on the top right to search for the keyword you are looking to find information about. Click on the corresponding result in the classes and interfaces tab. If you are searching for the term x then you click on the class / interface that has x at the end of the package name.
The first part of the Java documentation will tell you what interfaces the class you searched for implements and what classes it extends. This information is useful as all methods of the extended class will also be part of this part (directly or in overwritten form). It implementing Iterable for example tells you that the class has an iterator constructor and you can thus use it in for-each loops and iterate over it.
Fields, Constructors and Methods
This section is the one you will use the most as it contains all the information on what fields, constructors and methods are available and what they do and how to call them. You can click on the method and then a more detailed description will be shown to you.
Java Documentation in Eclipse
You can open the Java Documentation by clicking on a class / method / interface you would like to see the Java documentation off and then press F2 (Fn must be on). This will open a little window. From there you can also click the "Open Attached Javadoc in Browser" to see the actual Java documentation inside of Eclipse. This link has been helpful as well.