Make Discord the flagship notification method for player joins

.github/workflows/test.yml

@@ -0,0 +1,30 @@
+name: Run Tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up JDK 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+        cache: 'gradle'
+
+    - name: Run tests with Gradle
+      run: gradle test --no-daemon
+
+    - name: Publish test results
+      uses: EnricoMi/publish-unit-test-result-action@v2
+      if: always()
+      with:
+        files: |
+          build/test-results/**/*.xml

.gitignore

@@ -112,4 +112,8 @@ buildNumber.properties
 # Common working directory
 run/
 
-.env
+.env
+
+# Gradle
+.gradle/
+build/

README.md

@@ -1,10 +1,12 @@
 # Herald
-Herald is a Minecraft server plugin that sends email notifications when players join the server.
+Herald is a Minecraft server plugin that sends notifications when players join the server. It supports both email and Discord notifications.
 
 ![screenshot of emails](./screenshots/mailhog-7-1-2025.PNG)
 
 ## Features
 - Email notification system for player logins
+- Discord webhook notifications for player logins
+- Configurable notification methods (email, Discord, or both)
 - Easy to configure and use
 - Built-in mail server setup with Docker
 
@@ -42,10 +44,10 @@ This setup creates two mail-related services:
 All emails sent to the mail server are relayed to MailHog, where you can view them in a convenient web interface.
 
 ## Configuration
-After first run, a configuration file will be created that you can modify to set up your email notification preferences.
+After first run, a configuration file will be created that you can modify to set up your notification preferences.
 
 ### Herald Plugin Configuration
-Update your Herald `config.yml` to use the mail server:
+Update your Herald `config.yml` to configure email and/or Discord notifications:
 
 ```yaml
 # Herald Configuration
@@ -66,10 +68,31 @@ smtp:
 
 email:
   sender: "minecraft@minecraft-mail.local"
+
+# Discord Configuration
+discord:
+  enabled: false         # Set to true to enable Discord notifications
+  webhook-url: ""        # Your Discord webhook URL
 ```
 
 Make sure to replace "mailserver" with your server's IP address if your Minecraft server is not running in the same Docker network.
 
+### Setting up Discord Notifications
+To enable Discord notifications:
+
+1. In your Discord server, go to Server Settings → Integrations → Webhooks
+2. Click "New Webhook"
+3. Configure the webhook:
+   - Set a name (e.g., "Herald Bot")
+   - Choose the channel where notifications should be sent
+   - Copy the webhook URL
+4. In your Herald `config.yml`, set:
+   - `discord.enabled: true`
+   - `discord.webhook-url: "<your-webhook-url>"`
+5. Restart your Minecraft server or reload the plugin
+
+You can use Discord notifications alone or in combination with email notifications.
+
 ## Testing
 The Docker Compose setup includes a test Minecraft server that can be used to test the Herald plugin:
 

build.gradle

@@ -21,12 +21,20 @@ repositories {
 dependencies {
     compileOnly("org.spigotmc:spigot-api:1.21.4-R0.1-SNAPSHOT")
     implementation 'com.sun.mail:jakarta.mail:2.0.1'
+
+    // Test dependencies
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.10.2'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
 tasks {
     runServer {
         minecraftVersion("1.21")
     }
+
+    test {
+        useJUnitPlatform()
+    }
 }
 
 def targetJavaVersion = 21

src/main/java/com/dansplugins/herald/DiscordNotifier.java

@@ -0,0 +1,62 @@
+package com.dansplugins.herald;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+
+public class DiscordNotifier {
+
+    private final String webhookUrl;
+
+    public DiscordNotifier(String webhookUrl) {
+        this.webhookUrl = webhookUrl;
+    }
+
+    /**
+     * Send a message to Discord via webhook
+     * @param content The message content to send
+     * @throws IOException if there's an error sending the message
+     */
+    public void sendMessage(String content) throws IOException {
+        if (webhookUrl == null || webhookUrl.isEmpty()) {
+            throw new IllegalArgumentException("Discord webhook URL is not configured");
+        }
+
+        URL url = new URL(webhookUrl);
+        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+        connection.setRequestMethod("POST");
+        connection.setRequestProperty("Content-Type", "application/json");
+        connection.setDoOutput(true);
+
+        // Create JSON payload with the message content
+        String jsonPayload = String.format("{\"content\": \"%s\"}", escapeJson(content));
+
+        try (OutputStream os = connection.getOutputStream()) {
+            byte[] input = jsonPayload.getBytes(StandardCharsets.UTF_8);
+            os.write(input, 0, input.length);
+        }
+
+        int responseCode = connection.getResponseCode();
+        if (responseCode < 200 || responseCode >= 300) {
+            throw new IOException("Discord webhook returned error code: " + responseCode);
+        }
+    }
+
+    /**
+     * Escape special characters in JSON strings
+     * @param text The text to escape
+     * @return The escaped text
+     */
+    String escapeJson(String text) {
+        if (text == null) {
+            return "";
+        }
+        return text.replace("\\", "\\\\")
+                   .replace("\"", "\\\"")
+                   .replace("\n", "\\n")
+                   .replace("\r", "\\r")
+                   .replace("\t", "\\t");
+    }
+}

src/main/java/com/dansplugins/herald/Herald.java

@@ -21,6 +21,9 @@ public final class Herald extends JavaPlugin implements Listener {
     private String smtpPassword;
     private String emailSender;
     private boolean useTLS;
+    private boolean discordEnabled;
+    private String discordWebhookUrl;
+    private DiscordNotifier discordNotifier;
 
     @Override
     public void onEnable() {
@@ -52,6 +55,16 @@ private void loadConfiguration() {
         smtpPassword = getConfig().getString("smtp.password");
         emailSender = getConfig().getString("email.sender");
         useTLS = getConfig().getBoolean("smtp.use-tls", true);
+
+        // Load Discord settings
+        discordEnabled = getConfig().getBoolean("discord.enabled", false);
+        discordWebhookUrl = getConfig().getString("discord.webhook-url");
+
+        // Initialize Discord notifier if enabled
+        if (discordEnabled && discordWebhookUrl != null && !discordWebhookUrl.isEmpty()) {
+            discordNotifier = new DiscordNotifier(discordWebhookUrl);
+            getLogger().info("Discord notifications enabled");
+        }
     }
 
     @EventHandler
@@ -73,6 +86,21 @@ public void onPlayerJoin(PlayerJoinEvent event) {
                 e.printStackTrace();
             }
         });
+
+        // Send Discord notification if enabled
+        if (discordEnabled && discordNotifier != null) {
+            String discordMessage = "**" + playerName + "** joined the **" + serverName + "** server";
+
+            getServer().getScheduler().runTaskAsynchronously(this, () -> {
+                try {
+                    discordNotifier.sendMessage(discordMessage);
+                    getLogger().info("Discord notification sent successfully for player: " + playerName);
+                } catch (Exception e) {
+                    getLogger().severe("Failed to send Discord notification: " + e.getMessage());
+                    e.printStackTrace();
+                }
+            });
+        }
     }
 
     private void sendEmail(String subject, String body) throws MessagingException {

src/main/resources/config.yml

@@ -15,4 +15,9 @@ smtp:
   use-tls: false       # Set to true if using port 587
 
 email:
-  sender: "minecraft@minecraft-mail.local"
+  sender: "minecraft@minecraft-mail.local"
+
+# Discord Configuration
+discord:
+  enabled: false       # Set to true to enable Discord notifications
+  webhook-url: ""      # Discord webhook URL for the channel you want to send notifications to

src/main/resources/plugin.yml

@@ -3,4 +3,4 @@ version: '${version}'
 main: com.dansplugins.herald.Herald
 api-version: '1.16'
 authors: ["Daniel McCoy Stephenson"]
-description: Sends email notifications when players join the server
+description: Sends email and Discord notifications when players join the server