Sending a BufferedImage with Discord4J

Test.java

package lt.ekgame.animation_test;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.SQLException;
import java.util.EnumSet;
import java.util.Set;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;

import org.apache.http.HttpEntity;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.message.BasicNameValuePair;

import com.google.gson.JsonSyntaxException;

import sx.blah.discord.Discord4J;
import sx.blah.discord.api.ClientBuilder;
import sx.blah.discord.api.EventDispatcher;
import sx.blah.discord.api.IDiscordClient;
import sx.blah.discord.api.IListener;
import sx.blah.discord.api.internal.DiscordEndpoints;
import sx.blah.discord.api.internal.DiscordUtils;
import sx.blah.discord.api.internal.Requests;
import sx.blah.discord.handle.impl.events.MessageReceivedEvent;
import sx.blah.discord.handle.impl.events.MessageSendEvent;
import sx.blah.discord.handle.impl.events.ReadyEvent;
import sx.blah.discord.handle.obj.IChannel;
import sx.blah.discord.handle.obj.IGuild;
import sx.blah.discord.handle.obj.IMessage;
import sx.blah.discord.handle.obj.IUser;
import sx.blah.discord.handle.obj.Permissions;
import sx.blah.discord.json.responses.MessageResponse;
import sx.blah.discord.util.DiscordException;
import sx.blah.discord.util.HTTP429Exception;
import sx.blah.discord.util.MissingPermissionsException;

public class Test {
	
	public static void main(String... args) throws DiscordException, SQLException {
		String token = "...";
		final IDiscordClient client = new ClientBuilder().withToken(token).login();
		EventDispatcher dispatcher = client.getDispatcher();
		
		dispatcher.registerListener(new IListener<MessageReceivedEvent>() {
			public void handle(MessageReceivedEvent event) {
				
				IChannel channel = event.getMessage().getChannel();
				
				BufferedImage img = new BufferedImage(50, 50, BufferedImage.TYPE_INT_ARGB);
				Graphics2D graphics = img.createGraphics();
				graphics.setColor(Color.BLACK);
				graphics.drawLine(0, 0, 50, 50);
				
				try {
					ByteArrayOutputStream output = new ByteArrayOutputStream();
					ImageIO.write(img, "png", output);
					sendBytesAsFile(client, channel, output.toByteArray(), "image/png", "thing.png");
				} catch (IOException e) {
					e.printStackTrace();
				} catch (JsonSyntaxException e) {
					e.printStackTrace();
				} catch (HTTP429Exception e) {
					e.printStackTrace();
				} catch (DiscordException e) {
					e.printStackTrace();
				} catch (MissingPermissionsException e) {
					e.printStackTrace();
				}
			}
		});
	}
	
	public static IMessage sendBytesAsFile(IDiscordClient client, IChannel channel, byte[] bytes, String mime, String filename) throws JsonSyntaxException, HTTP429Exception, DiscordException, MissingPermissionsException {
		DiscordUtils.checkPermissions(client, channel, EnumSet.of(Permissions.SEND_MESSAGES, Permissions.ATTACH_FILES));
		
		if (client.isReady()) {
			MultipartEntityBuilder builder = MultipartEntityBuilder.create().addBinaryBody("file", bytes, ContentType.create(mime), filename);

			HttpEntity fileEntity = builder.build();
			MessageResponse response = DiscordUtils.GSON.fromJson(Requests.POST.makeRequest(
					DiscordEndpoints.CHANNELS+channel.getID()+"/messages",
					fileEntity, new BasicNameValuePair("authorization", client.getToken())), MessageResponse.class);
			IMessage message = DiscordUtils.getMessageFromJSON(client, channel, response);
			client.getDispatcher().dispatch(new MessageSendEvent(message));
			return message;
		} else {
			Discord4J.LOGGER.error("Bot has not signed in yet!");
			return null;
		}
	}
}

Cool

Can you give a tutorial ?

Because , I am new to java.

help!!!

This is what I did, I used ImageIO.write to get

BufferedImage bufferedImage; // pretend this is initialized
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "png", outputStream);
InputStream inputStream = new ByteArrayInputStream(outputStream.toByteArray());
event.getMessage().getChannel().block().createMessage(messageCreateSpec ->
{
	messageCreateSpec.addFile("output.png", inputStream);
}).block();