JDA - 如何等待下一条消息

我正在使用 JDA 制作一个不和谐的机器人，我想知道如何等待消息。像这样的东西

import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
import net.dv8tion.jda.api.hooks.ListenerAdapter;

public class Listener extends ListenerAdapter {
    public void onGuildMessageReceived(GuildMessageReceivedEvent event) {
        String message = event.getMessage().getContentRaw();
        boolean isBot = event.getAuthor().isBot();

        // Check if message is not from a bot
        if (!isBot) {
            if (message.equalsIgnoreCase("hi")) {
                event.getChannel().sendMessage("Hello, what's your name?").queue();
                // Wait for second message
                String name = event.getMessage().getContentRaw(); // Saving content from second message
                event.getChannel().sendMessage("Your name is: " + name).queue();
            }
        }
    }
}

User: Hi

机器人：你好，你叫什么名字？

User: 发送姓名

机器人：你的名字是：name

我如何收到第二条消息？

正如已经告诉过的Minn在评论中。您可以使用线程中给出的方法。不过，我建议使用 JDA-Utilities EventWaiter。

如果您使用 Maven 或 Gradle，请使用其中之一：

<!--- Place this in your repositories block --->
  <repository>
    <id>central</id>
    <name>bintray</name>
    <url>http://jcenter.bintray.com</url>
  </repository>

<!--- Place this in your dependencies block --->
  <dependency>
    <groupId>com.jagrosh</groupId>
    <artifactId>jda-utilities</artifactId>
    <version>JDA-UTILITIES-VERSION</version>  <!--- This will be the latest JDA-Utilities version. Currently: 3.0.4 --->
    <scope>compile</scope>
    <type>pom</type>
  </dependency>
  <dependency>
    <groupId>net.dv8tion</groupId>
    <artifactId>JDA</artifactId> <!--- This will be your JDA Version --->
    <version>JDA-VERSION</version>
  </dependency>

对于 gradle 来说更容易：

# Add this to the dependencies (What's inside this block, not the block itself.

dependencies {
    compile 'com.jagrosh:jda-utilities:JDA-UTILITIES-VERSION'
    compile 'net.dv8tion:JDA:JDA-VERSION'
}

# Same story for the repo's
repositories {
    jcenter()
}

加载后，我建议检查ExampleBot 主类。添加你自己的东西。因为我只会解释让 EventWaiter 工作的基础知识。

这将是机器人的主要类，当您运行它时，它将使用这些命令启动机器人。 ShutdownCommand 和 PingCommand 是实用程序的一部分。所以这些会自动添加。

public static void main(String[] args) throws IOException, LoginException, IllegalArgumentException, RateLimitedException
    {
        // the first is the bot token
        String token = "The token of your bot"
        // the second is the bot's owner's id
        String ownerId = "The ID of your user account"
        // define an eventwaiter, dont forget to add this to the JDABuilder!
        EventWaiter waiter = new EventWaiter();
        // define a command client
        CommandClientBuilder client = new CommandClientBuilder();
        // sets the owner of the bot
        client.setOwnerId(ownerId);
        // sets the bot prefix
        client.setPrefix("!!");
        // adds commands
        client.addCommands(
                // command to say hello
                new HelloCommand(waiter),
                // command to check bot latency
                new PingCommand(),
                // command to shut off the bot
                new ShutdownCommand());

        // start getting a bot account set up
        new JDABuilder(AccountType.BOT)
                // set the token
                .setToken(token)
                // set the game for when the bot is loading
                .setStatus(OnlineStatus.DO_NOT_DISTURB)
                .setActivity(Activity.playing("loading..."))
                // add the listeners
                .addEventListeners(waiter, client.build())
                // start it up!
                .build();
    }

现在，对于你好命令。首先创建一个名为“HelloCommand”的新类。在本课程中，您将扩展实用程序的“命令”部分。

public class HelloCommand extends Command
{
    private final EventWaiter waiter; // This variable is used to define the waiter, and call it from anywhere in this class.

    public HelloCommand(EventWaiter waiter)
    {
        this.waiter = waiter; // Define the waiter
        this.name = "hello"; // The command
        this.aliases = new String[]{"hi"}; // Any aliases about the command 
        this.help = "says hello and waits for a response"; // Description of the command
    }
    
    @Override
    protected void execute(CommandEvent event)
    {
        // ask what the user's name is
        event.reply("Hello. What is your name?"); // Respond to the command with a message.
        
        // wait for a response
        waiter.waitForEvent(MessageReceivedEvent.class, 
                // make sure it's by the same user, and in the same channel, and for safety, a different message
                e -> e.getAuthor().equals(event.getAuthor()) 
                        && e.getChannel().equals(event.getChannel()) 
                        && !e.getMessage().equals(event.getMessage()), 
                // respond, inserting the name they listed into the response
                e -> event.reply("Hello, `"+e.getMessage().getContentRaw()+"`! I'm `"+e.getJDA().getSelfUser().getName()+"`!"),
                // if the user takes more than a minute, time out
                1, TimeUnit.MINUTES, () -> event.reply("Sorry, you took too long."));
    }
    
}

现在，我们就到这里来看看有趣的东西了。使用事件服务员时。您需要检查几个区域。

        // wait for a response
        waiter.waitForEvent(MessageReceivedEvent.class, 
                // make sure it's by the same user, and in the same channel, and for safety, a different message
                e -> e.getAuthor().equals(event.getAuthor()) 
                        && e.getChannel().equals(event.getChannel()) 
                        && !e.getMessage().equals(event.getMessage()), 
                // respond, inserting the name they listed into the response
                e -> event.reply("Hello, `"+e.getMessage().getContentRaw()+"`! I'm `"+e.getJDA().getSelfUser().getName()+"`!"),
                // if the user takes more than a minute, time out
                1, TimeUnit.MINUTES, () -> event.reply("Sorry, you took too long."));

更详细地解释：

        waiter.waitForEvent(GuildMessageReceivedEvent.class, // What event do you want to wait for?
            p -> p.getAuthor().equals(message.getAuthor()) && p.getChannel().equals(message.getChannel()), // This is important to get correct, check if the user is the same as the one who executed the command. Otherwise you'll get a user who isn't the one who executed it and the waiter responds to it.
            run -> {
            // Run whatever stuff you want here.
        }, 1, // How long should it wait for an X amount of Y?
            TimeUnit.MINUTES, // Y == TimeUnit.<TIME> (Depending on the use case, a different time may be needed)
            () -> message.getChannel().sendMessage("You took longer then a minute to respond. So I've reverted this message.").queue()); // If the user never responds. Do this.

这应该是BASICS使用EventWaiter。这可能取决于您的用例。也可以仅使用 eventwaiter 类来完成。