DiscordBot JDA get all Messages in a Channel

Hey I tried to get all the messages from a channel but I always failed. I've already searched for similar questions and tried them but I couldn't find a solution...

I also tried @Minn's solution but it didn't work:

channel.getHistory().retrievePast(2)
       .map(messages -> messages.get(1)) // this assumes that the channel has at least 2 messages
       .queue(message -> { // success callback
           System.out.println("The second most recent message is: " + message.getContentDisplay();
       });

Or rather, I didn't manage to rescript it so that all messages are collected.

I found a Solution...

MessageHistory history = MessageHistory.getHistoryFromBeginning(channel).complete();
List<Message> mess = history.getRetrievedHistory();