Model

.gitignore

@@ -1,2 +1,3 @@
 target/
 /.idea/
+.env

pom.xml

@@ -45,6 +45,32 @@
             <artifactId>javafx-fxml</artifactId>
             <version>${javafx.version}</version>
         </dependency>
+        <dependency>
+            <groupId>io.github.cdimascio</groupId>
+            <artifactId>dotenv-java</artifactId>
+            <version>3.2.0</version>
+        </dependency>
+        <dependency>
+            <groupId>tools.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>3.0.1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjfx</groupId>
+            <artifactId>javafx-swing</artifactId>
+            <version>26-ea+16</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>2.0.17</version>
+        </dependency>
+        <dependency>
+            <groupId>org.wiremock</groupId>
+            <artifactId>wiremock</artifactId>
+            <version>4.0.0-beta.15</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

src/main/java/com/example/HelloController.java

@@ -1,22 +1,59 @@
 package com.example;
 
+import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
 import javafx.scene.control.Label;
+import javafx.scene.control.ListCell;
+import javafx.scene.control.ListView;
+import javafx.scene.control.TextField;
 
 /**
  * Controller layer: mediates between the view (FXML) and the model.
  */
 public class HelloController {
 
-    private final HelloModel model = new HelloModel();
+    private final HelloModel model = new HelloModel(new NtfyConnectionImpl());
+
+    @FXML
+    public ListView<NtfyMessageDto> messageView;
 
     @FXML
     private Label messageLabel;
 
+    @FXML
+    private TextField messageInput;
+
     @FXML
     private void initialize() {
         if (messageLabel != null) {
             messageLabel.setText(model.getGreeting());
         }
+        messageView.setItems(model.getMessages());
+
+        if (messageInput != null) {
+            messageInput.textProperty().bindBidirectional(model.messageToSendProperty());
+        }
+
+        messageView.setCellFactory(param -> new ListCell<>() {
+            @Override
+            protected void updateItem(NtfyMessageDto item, boolean empty) {
+                super.updateItem(item, empty);
+
+                if (empty || item == null) {
+                    setText(null);
+                } else {
+                    var time = java.time.Instant.ofEpochSecond(item.time())
+                            .atZone(java.time.ZoneId.systemDefault())
+                            .toLocalTime();
+                    var formatter = java.time.format.DateTimeFormatter.ofPattern("HH:mm");
+                    setText(time.format(formatter) + " " + item.message());
+                }
+            }
+        });
+    }
+
+
+    public void sendMessage(ActionEvent actionEvent) {
+        model.sendMessage();
     }
 }

src/main/java/com/example/HelloFX.java

@@ -1,5 +1,6 @@
 package com.example;
 
+import io.github.cdimascio.dotenv.Dotenv;
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
@@ -10,6 +11,14 @@ public class HelloFX extends Application {
 
     @Override
     public void start(Stage stage) throws Exception {
+        Dotenv dotenv = Dotenv.configure()
+                .ignoreIfMissing()
+                .load();
+        String hostName = dotenv.get("HOST_NAME");
+        if (hostName != null) {
+            System.out.println("Connected to: " + hostName);
+        }
+
         FXMLLoader fxmlLoader = new FXMLLoader(HelloFX.class.getResource("hello-view.fxml"));
         Parent root = fxmlLoader.load();
         Scene scene = new Scene(root, 640, 480);

src/main/java/com/example/HelloModel.java

@@ -1,9 +1,61 @@
 package com.example;
 
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import io.github.cdimascio.dotenv.Dotenv;
+import javafx.application.Platform;
+import javafx.beans.property.SimpleStringProperty;
+import javafx.beans.property.StringProperty;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import tools.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.ArrayList;
+import java.util.Objects;
+import java.util.function.Consumer;
+
 /**
  * Model layer: encapsulates application data and business logic.
  */
 public class HelloModel {
+
+    private final NtfyConnection connection;
+
+    private final Consumer<Runnable> uiExecutor;
+
+    private final ObservableList<NtfyMessageDto> messages = FXCollections.observableArrayList();
+    private final StringProperty messageToSend = new SimpleStringProperty();
+
+    public HelloModel(NtfyConnection connection, Consumer<Runnable> uiExecutor) {
+        this.connection = connection;
+        this.uiExecutor = uiExecutor;
+        receiveMessage();
+    }
+
+    public HelloModel(NtfyConnection connection) {
+        this(connection, Platform::runLater);
+    }
+
+    public ObservableList<NtfyMessageDto> getMessages() {
+        return messages;
+    }
+
+    public String getMessageToSend() {
+        return messageToSend.get();
+    }
+
+    public StringProperty messageToSendProperty() {
+        return messageToSend;
+    }
+
+    public void setMessageToSend(String message) {
+        messageToSend.set(message);
+    }
+
     /**
      * Returns a greeting based on the current Java and JavaFX versions.
      */
@@ -12,4 +64,15 @@ public String getGreeting() {
         String javafxVersion = System.getProperty("javafx.version");
         return "Hello, JavaFX " + javafxVersion + ", running on Java " + javaVersion + ".";
     }
+    public void sendMessage() {
+        String msg = messageToSend.get();
+        if (msg != null && !msg.isBlank()) {
+            connection.sendMessage(msg);
+        }
+    }
+
+    public void receiveMessage() {
+        connection.receiveMessage(m -> uiExecutor.accept(() -> messages.add(m)));
+    }
 }
+

src/main/java/com/example/NtfyConnection.java

@@ -0,0 +1,10 @@
+package com.example;
+
+import java.util.function.Consumer;
+
+public interface NtfyConnection {
+
+    public boolean sendMessage(String message);
+
+    public void receiveMessage(Consumer<NtfyMessageDto> messageHandler);
+}

src/main/java/com/example/NtfyConnectionImpl.java

@@ -0,0 +1,95 @@
+package com.example;
+
+import io.github.cdimascio.dotenv.Dotenv;
+import javafx.application.Platform;
+import tools.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+public class NtfyConnectionImpl implements NtfyConnection {
+
+    private final HttpClient http = HttpClient.newHttpClient();
+    private final String hostName;
+    private final ObjectMapper mapper = new ObjectMapper();
+
+    public NtfyConnectionImpl() {
+        Dotenv dotenv = Dotenv.load();
+        String envHost = dotenv.get("HOST_NAME");
+        if (envHost == null || envHost.isBlank()) {
+            throw new IllegalStateException("Environment variable 'HOST_NAME' is required but was not found.");
+        }
+        hostName = envHost;
+    }
+
+    public NtfyConnectionImpl(String hostName) {
+        this.hostName = hostName;
+    }
+
+    @Override
+    public boolean sendMessage(String message) {
+        //Todo: Send message using HTTPClient
+        HttpRequest httpRequest = HttpRequest.newBuilder()
+                .POST(HttpRequest.BodyPublishers.ofString(message))
+                .uri(URI.create(hostName + "/mytopic"))
+                .timeout(java.time.Duration.ofSeconds(5))
+                .build();
+        //Todo: handle long blocking send requests to not freeze the JavaFX thread
+        //1. Use thread send message?
+        //2. Use async?
+        var response = http.sendAsync(httpRequest, HttpResponse.BodyHandlers.ofString())
+                .orTimeout(5, java.util.concurrent.TimeUnit.SECONDS)
+                .join();
+        if (response.statusCode() != 200) {
+            System.err.println("Failed to send message. HTTP Status: " + response.statusCode());
+            System.err.println("Response body: " + response.body());
+            return false;
+        }
+        return true;
+    }
+
+
+    @Override
+    public void receiveMessage(Consumer<NtfyMessageDto> messageHandler) {
+        HttpRequest httpRequest = HttpRequest.newBuilder()
+                .GET()
+                .uri(URI.create(hostName + "/mytopic/json"))
+                .build();
+
+        http.sendAsync(httpRequest, HttpResponse.BodyHandlers.ofLines())
+                .thenAccept(response -> {
+                    if (response.statusCode() != 200) {
+                        System.err.println("Error connecting to stream. HTTP Status: " + response.statusCode());
+                        return;
+                    }
+                    response.body()
+                            .map(s -> {
+                                try {
+                                    return mapper.readValue(s, NtfyMessageDto.class);
+                                } catch (Exception e) {
+                                    System.err.println("Failed to parse JSON: " + e.getMessage());
+                                    return null;
+                                }
+                            })
+                            .filter(Objects::nonNull)
+                            .filter(message -> "message".equals(message.event()))
+                            .peek(m -> {
+                                var time = java.time.Instant.ofEpochSecond(m.time())
+                                        .atZone(java.time.ZoneId.systemDefault())
+                                        .toLocalTime();
+                                System.out.println(time + " " + m.message());
+                            })
+                            .forEach(messageHandler);
+                }).exceptionally(e -> {
+                    System.err.println("Async connection error: " + e.getMessage());
+                    e.printStackTrace();
+                    return null;
+                });
+    }
+}
+

src/main/java/com/example/NtfyMessageDto.java

@@ -0,0 +1,6 @@
+package com.example;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record NtfyMessageDto(String id, long time, String event, String topic, String message){}

src/main/java/module-info.java

@@ -1,6 +1,10 @@
 module hellofx {
     requires javafx.controls;
     requires javafx.fxml;
+    requires io.github.cdimascio.dotenv.java;
+    requires java.net.http;
+    requires tools.jackson.databind;
+    requires javafx.graphics;
 
     opens com.example to javafx.fxml;
     exports com.example;

src/main/resources/com/example/hello-view.fxml

@@ -2,8 +2,13 @@
 <?import javafx.scene.layout.StackPane?>
 <?import javafx.scene.control.Label?>
 
-<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://javafx.com/fxml" fx:controller="com.example.HelloController">
-    <children>
+<?import javafx.scene.layout.VBox?>
+<?import javafx.scene.control.Button?>
+<?import javafx.scene.control.ListView?>
+<?import javafx.scene.control.TextField?>
+<VBox alignment="CENTER" xmlns="http://javafx.com/javafx" xmlns:fx="http://javafx.com/fxml" fx:controller="com.example.HelloController">
         <Label fx:id="messageLabel" text="Hello, JavaFX!" />
-    </children>
-</StackPane>
+        <Button text="Send message" onAction="#sendMessage"/>
+        <ListView fx:id="messageView"/>
+        <TextField fx:id="messageInput"/>
+</VBox>