Authenticate in Confluence Cloud through JAVA

Hello everybody,

i already worked with in java to manage the JIRA-projects and issues. I could proceed very well so far.

Now, i would also manage the Confluence pages in Java.
For better understanding i show you an example from the web :

"import com.atlassian.confluence.pages.Page;
import com.atlassian.confluence.pages.PageManager;
import com.atlassian.spring.container.ContainerManager;

class MyPageManager {

public static Page createChildPage(Page parentPage, String pageTitel){
PageManager pageManager = (PageManager) ContainerManager.getComponent(“pageManager”);

Page child = new Page();
pageManager.saveContentEntity(child, null);

return child;

i would like to use the same (similar) approach.
But i can’t figure out how to AUTHENTICATE ??

I searched so much and still no answer.
In Jira it was the JiraRestClient, in Confluence i don’t know what it is.

i would appreciate any advice