Help for creating own library (add java file to sketch)

[quark]

@Wolfgang

i created a class called Adressbook. I copy the class inside the sketchbook.

I assume you mean Addressbook and that the file you created contains Java source code, not a compiled class

1. Name the file you created as Addressbook.java, must be the same name including capital letters as the class name.
2. The sketch name must NOT be the same as the class
3. The Addressbook.java file must be in the same folder as the sketch pde file.

@Wolfgang

and entered import Adressbook;

4. Do not add the import statement because it is not needed

@Wolfgang

no library found for Addressbook — I got as error.

5. Theis error was created because of the import statement.