Cant replaceAll using getMember on guildmemberjoin

Question

import net.dv8tion.jda.core.EmbedBuilder;
import net.dv8tion.jda.core.hooks.ListenerAdapter;

import java.awt.*;
import java.util.Random;

public class GuildMemberJoinEvent extends ListenerAdapter {

    String[] messages = {
            "[member] joined. You must construct additional pylons.",
            "Never gonna give [member] up. Never let [member] down!",
            "Hey! Listen! [member] has joined!",
            "Ha! [member] has joined! You activated my trap card!",
            "We've been expecting you, [member].",
            "It's dangerous to go alone, take [member]!",
            "Swoooosh. [member] just landed.",
            "Brace yourselves. [member] just joined the server.",
            "A wild [member] appeared.",
            "Is it hot in here or is it just me? Oh [member] joined that explains it"
    };
    public void onGuildMemberJoin(GuildMemberJoinEvent event){
        Random rand = new Random();
        int number = rand.nextInt(messages.length);

        EmbedBuilder join = new EmbedBuilder();
        join.setColor(Color.red);
        join.setDescription(messages[number].replaceAll("[member]]", event.getMember().getAsMention()));

    }
}

For some reason jda is not allowing me to event.getMember() when using replaceAll on guildjoinevent and i really dont have a clue as to why that is.

_For some reason jda is not allowing me to event.getMember() when using replaceAll on guildjoinevent_ – always to be as specific as possible – with this description we have to guess that _probably_ your problem is your usage of `replaceAll`; but maybe there's another problem (which would not be easy to see). So, if there's an error message, include it; if there's no error message, then include what you expect and what's actually happening (the unexpected outcome). Also refer to [How to create a Minimal, Reproducible Example](https://stackoverflow.com/help/minimal-reproducible-example). — Ivo Mori, Jul 14 '20 at 01:39
_i really dont have a clue as to why that is._ – Have a look at [How to debug small programs](https://ericlippert.com/2014/03/05/how-to-debug-small-programs/). — Ivo Mori, Jul 14 '20 at 01:42
Also, don't forget to accept an answer (tick the check-mark next to an answer) when it answers your question. In this way your question won't show up as unanswered in searches. — Ivo Mori, Jul 14 '20 at 01:44

Ivo Mori · Accepted Answer · 2020-07-14T01:59:59.490

You have two problems

There is a typo.
The 1^st argument for replaceAll is interpreted as a Regular Expression (regex), and [ ] defines a character class (has a special meaning within a regex).

How to solve it?

Fix your typo: "[member]]" ⟹ "[member]"
If you want to use replaceAll you need to escape [ ] ⟹ "\\[member]"

As an alternative you may use the replace method which does not take a regex as its 1^st argument, but the passed in string as a literal (meaning as is). However, you still need to fix your typo as in messages[number].replace("[member]", ...).

Probably it's easiest to look at it in a simplified manner

static String[] messages = {
        "[member] joined. You must construct additional pylons.",
        "Never gonna give [member] up. Never let [member] down!",
        "Hey! Listen! [member] has joined!",
        "Ha! [member] has joined! You activated my trap card!",
        "We've been expecting you, [member].",
        "It's dangerous to go alone, take [member]!",
        "Swoooosh. [member] just landed.",
        "Brace yourselves. [member] just joined the server.",
        "A wild [member] appeared.",
        "Is it hot in here or is it just me? Oh [member] joined that explains it"
};

public static void main(String[] args) {
    Random rand = new Random();
    int number = rand.nextInt(messages.length);

    String member = "Stanley42";

    String original = messages[number].replaceAll("[member]]", member);
    String originalWithEscaping = messages[number].replaceAll("\\[member]]", member);
    String fixedOriginal = messages[number].replaceAll("\\[member]", member);

    String useReplace = messages[number].replace("[member]]", member);
    String fixedUseReplace = messages[number].replace("[member]", member);

    System.out.println(original);
    System.out.println(originalWithEscaping);
    System.out.println(fixedOriginal);
    System.out.println(useReplace);
    System.out.println(fixedUseReplace);
}

will then give you this sample output

Never gonna give [membeStanley42 up. Never let [membeStanley42 down!
Never gonna give [member] up. Never let [member] down!
Never gonna give Stanley42 up. Never let Stanley42 down!
Never gonna give [member] up. Never let [member] down!
Never gonna give Stanley42 up. Never let Stanley42 down!

Thank you so much! this helped me understand it way better thanks to the simplied example, It still didnt allow me to use event.getMember().getAsMention but I figured it was bcs of the "public void onGuildMemberJoin(GuildMemberJoinEvent event)" which for some reason didnt allow that to happen so it changed it to "public void onGuildMemberJoin(net.dv8tion.jda.core.events.guild.member.GuildMemberJoinEvent event)" — Berdasco 19, Jul 14 '20 at 09:18

Cant replaceAll using getMember on guildmemberjoin

1 Answers1