WebhookBuilder

import javax.net.ssl.HttpsURLConnection;
import java.awt.*;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Array;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.List;

public class MessageBuilder {

    private final String url;

    private String content;

    private String username;

    private String avatarUrl;

    private boolean tts;

    private List<EmbedObject> embeds = new ArrayList<>();

    public MessageBuilder(String webhook) {
        this.url = webhook;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setAvatarUrl(String avatarUrl) {
        this.avatarUrl = avatarUrl;
    }

    public void setTts(boolean tts) {
        this.tts = tts;
    }

    public void addEmbed(EmbedObject embed) {
        this.embeds.add(embed);
    }

    public void execute() throws IOException {
        if (this.content == null && this.embeds.isEmpty())
            throw new IllegalArgumentException("Set content or add at least one EmbedObject");
        JSONObject json = new JSONObject();
        json.put("content", this.content);
        json.put("username", this.username);
        json.put("avatar_url", this.avatarUrl);
        json.put("tts", Boolean.valueOf(this.tts));
        if (!this.embeds.isEmpty()) {
            List<JSONObject> embedObjects = new ArrayList<>();
            for (EmbedObject embed : this.embeds) {
                JSONObject jsonEmbed = new JSONObject();
                jsonEmbed.put("title", embed.getTitle());
                jsonEmbed.put("description", embed.getDescription());
                jsonEmbed.put("url", embed.getUrl());
                if (embed.getColor() != null) {
                    Color color = embed.getColor();
                    int rgb = color.getRed();
                    rgb = (rgb << 8) + color.getGreen();
                    rgb = (rgb << 8) + color.getBlue();
                    jsonEmbed.put("color", Integer.valueOf(rgb));
                }
                EmbedObject.Footer footer = embed.getFooter();
                EmbedObject.Image image = embed.getImage();
                EmbedObject.Thumbnail thumbnail = embed.getThumbnail();
                EmbedObject.Author author = embed.getAuthor();
                List<EmbedObject.Field> fields = embed.getFields();
                if (footer != null) {
                    JSONObject jsonFooter = new JSONObject();
                    jsonFooter.put("text", footer.getText());
                    jsonFooter.put("icon_url", footer.getIconUrl());
                    jsonEmbed.put("footer", jsonFooter);
                }
                if (image != null) {
                    JSONObject jsonImage = new JSONObject();
                    jsonImage.put("url", image.getUrl());
                    jsonEmbed.put("image", jsonImage);
                }
                if (thumbnail != null) {
                    JSONObject jsonThumbnail = new JSONObject();
                    jsonThumbnail.put("url", thumbnail.getUrl());
                    jsonEmbed.put("thumbnail", jsonThumbnail);
                }
                if (author != null) {
                    JSONObject jsonAuthor = new JSONObject();
                    jsonAuthor.put("name", author.getName());
                    jsonAuthor.put("url", author.getUrl());
                    jsonAuthor.put("icon_url", author.getIconUrl());
                    jsonEmbed.put("author", jsonAuthor);
                }
                List<JSONObject> jsonFields = new ArrayList<>();
                for (EmbedObject.Field field : fields) {
                    JSONObject jsonField = new JSONObject();
                    jsonField.put("name", field.getName());
                    jsonField.put("value", field.getValue());
                    jsonField.put("inline", Boolean.valueOf(field.isInline()));
                    jsonFields.add(jsonField);
                }
                jsonEmbed.put("fields", jsonFields.toArray());
                embedObjects.add(jsonEmbed);
            }
            json.put("embeds", embedObjects.toArray());
        }
        URL url = new URL(this.url);
        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.addRequestProperty("Content-Type", "application/json");
        connection.addRequestProperty("User-Agent", "Dan");
        connection.setDoOutput(true);
        connection.setRequestMethod("POST");
        OutputStream stream = connection.getOutputStream();
        stream.write(json.toString().getBytes(StandardCharsets.UTF_8));
        stream.flush();
        stream.close();
        connection.getInputStream().close();
        connection.disconnect();
    }

    public static class EmbedObject {
        private String title;

        private String description;

        private String url;

        private Color color;

        private Footer footer;

        private Thumbnail thumbnail;

        private Image image;

        private Author author;

        private List<Field> fields = new ArrayList<>();

        public String getTitle() {
            return this.title;
        }

        public EmbedObject setTitle(String title) {
            this.title = title;
            return this;
        }

        public String getDescription() {
            return this.description;
        }

        public EmbedObject setDescription(String description) {
            this.description = description;
            return this;
        }

        public String getUrl() {
            return this.url;
        }

        public EmbedObject setUrl(String url) {
            this.url = url;
            return this;
        }

        public Color getColor() {
            return this.color;
        }

        public EmbedObject setColor(Color color) {
            this.color = color;
            return this;
        }

        public Footer getFooter() {
            return this.footer;
        }

        public Thumbnail getThumbnail() {
            return this.thumbnail;
        }

        public EmbedObject setThumbnail(String url) {
            this.thumbnail = new Thumbnail(url);
            return this;
        }

        public Image getImage() {
            return this.image;
        }

        public EmbedObject setImage(String url) {
            this.image = new Image(url);
            return this;
        }

        public Author getAuthor() {
            return this.author;
        }

        public List<Field> getFields() {
            return this.fields;
        }

        public EmbedObject setFooter(String text, String icon) {
            this.footer = new Footer(text, icon);
            return this;
        }

        public EmbedObject setAuthor(String name, String url, String icon) {
            this.author = new Author(name, url, icon);
            return this;
        }

        public EmbedObject addField(String name, String value, boolean inline) {
            this.fields.add(new Field(name, value, inline));
            return this;
        }

        private class Footer {
            private String text;

            private String iconUrl;

            private Footer(String text, String iconUrl) {
                this.text = text;
                this.iconUrl = iconUrl;
            }

            private String getText() {
                return this.text;
            }

            private String getIconUrl() {
                return this.iconUrl;
            }
        }

        private class Thumbnail {
            private String url;

            private Thumbnail(String url) {
                this.url = url;
            }

            private String getUrl() {
                return this.url;
            }
        }

        private class Image {
            private String url;

            private Image(String url) {
                this.url = url;
            }

            private String getUrl() {
                return this.url;
            }
        }

        private class Author {
            private String name;

            private String url;

            private String iconUrl;

            private Author(String name, String url, String iconUrl) {
                this.name = name;
                this.url = url;
                this.iconUrl = iconUrl;
            }

            private String getName() {
                return this.name;
            }

            private String getUrl() {
                return this.url;
            }

            private String getIconUrl() {
                return this.iconUrl;
            }
        }

        private class Field {
            private String name;

            private String value;

            private boolean inline;

            private Field(String name, String value, boolean inline) {
                this.name = name;
                this.value = value;
                this.inline = inline;
            }

            private String getName() {
                return this.name;
            }

            private String getValue() {
                return this.value;
            }

            private boolean isInline() {
                return this.inline;
            }
        }
    }

    private class Footer {
        private String text;

        private String iconUrl;

        private Footer(String text, String iconUrl) {
            this.text = text;
            this.iconUrl = iconUrl;
        }

        private String getText() {
            return this.text;
        }

        private String getIconUrl() {
            return this.iconUrl;
        }
    }

    private class Thumbnail {
        private String url;

        private Thumbnail(String url) {
            this.url = url;
        }

        private String getUrl() {
            return this.url;
        }
    }

    private class Image {
        private String url;

        private Image(String url) {
            this.url = url;
        }

        private String getUrl() {
            return this.url;
        }
    }

    private class Author {
        private String name;

        private String url;

        private String iconUrl;

        private Author(String name, String url, String iconUrl) {
            this.name = name;
            this.url = url;
            this.iconUrl = iconUrl;
        }

        private String getName() {
            return this.name;
        }

        private String getUrl() {
            return this.url;
        }

        private String getIconUrl() {
            return this.iconUrl;
        }
    }

    private class Field {
        private String name;

        private String value;

        private boolean inline;

        private Field(String name, String value, boolean inline) {
            this.name = name;
            this.value = value;
            this.inline = inline;
        }

        private String getName() {
            return this.name;
        }

        private String getValue() {
            return this.value;
        }

        private boolean isInline() {
            return this.inline;
        }
    }

    private class JSONObject {
        private final HashMap<String, Object> map = new HashMap<>();

        private JSONObject() {
        }

        void put(String key, Object value) {
            if (value != null)
                this.map.put(key, value);
        }

        public String toString() {
            StringBuilder builder = new StringBuilder();
            Set<Map.Entry<String, Object>> entrySet = this.map.entrySet();
            builder.append("{");
            int i = 0;
            for (Map.Entry<String, Object> entry : entrySet) {
                Object val = entry.getValue();
                builder.append(quote(entry.getKey())).append(":");
                if (val instanceof String) {
                    builder.append(quote(String.valueOf(val)));
                } else if (val instanceof Integer) {
                    builder.append(Integer.valueOf(String.valueOf(val)));
                } else if (val instanceof Boolean) {
                    builder.append(val);
                } else if (val instanceof JSONObject) {
                    builder.append(val.toString());
                } else if (val.getClass().isArray()) {
                    builder.append("[");
                    int len = Array.getLength(val);
                    for (int j = 0; j < len; j++)
                        builder.append(Array.get(val, j).toString()).append((j != len - 1) ? "," : "");
                    builder.append("]");
                }
                builder.append((++i == entrySet.size()) ? "}" : ",");
            }
            return builder.toString();
        }

        private String quote(String string) {
            return "\"" + string + "\"";
        }
    }
}