Classes part of sending logic.

src/main/java/java/src/Sending/Data/OnlineStateNotification.java

@@ -0,0 +1,31 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record OnlineStateNotification(Peer sender, Peer receiver) implements Sendable {
+
+    @Override
+    public EDataType getType() {
+        return EDataType.OnlineStateNotification;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String request =
+            "{\"onlineState\":\"online\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return request.getBytes();
+    }
+    
+}

src/main/java/java/src/Sending/Data/OnlineStateRequest.java

@@ -0,0 +1,31 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record OnlineStateRequest(Peer sender, Peer receiver) implements Sendable {
+
+    @Override
+    public EDataType getType() {
+        return EDataType.OnlineStateRequest;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String request =
+            "{\"onlineState\":\"\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return request.getBytes();
+    }
+    
+}

src/main/java/java/src/Sending/Data/OnlineStateResponse.java

@@ -0,0 +1,31 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record OnlineStateResponse(Peer sender, Peer receiver) implements Sendable {
+
+    @Override
+    public EDataType getType() {
+        return EDataType.OnlineStateResponse;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String response =
+            "{\"onlineState\":\"online\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return response.getBytes();
+    }
+    
+}

src/main/java/java/src/Sending/Data/PublishFileNameNotification.java

@@ -0,0 +1,31 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record PublishFileNameNotification(Peer sender, Peer receiver, String fileName) implements Sendable {
+
+    @Override
+    public EDataType getType() {
+        return EDataType.PublishFileNameNotification;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String response =
+            "{\"publishFileName\":\"" + fileName +"\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return response.getBytes();
+    }
+    
+}

src/main/java/java/src/Sending/Data/PullFileListRequest.java

@@ -0,0 +1,34 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+/**
+ * Is never getting sent because szenario is, that all peers come online and stay online forever.
+ */
+public record PullFileListRequest(Peer sender, Peer receiver) implements Sendable {
+
+    @Override
+    public EDataType getType() {
+        return EDataType.PullFileListRequest;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String response =
+            "{\"pullFileList\":\"\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return response.getBytes();
+    }
+    
+}

src/main/java/java/src/Sending/Data/PullFileRequest.java

@@ -0,0 +1,31 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record PullFileRequest(Peer sender, Peer receiver, String fileName) implements Sendable {
+    
+    @Override
+    public EDataType getType() {
+        return EDataType.PullFileRequest;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String response =
+            "{\"pullFile\":\"" + fileName + "\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return response.getBytes();
+    }
+
+}

src/main/java/java/src/Sending/Data/SendFileReply.java

@@ -0,0 +1,33 @@
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+public record SendFileReply(Peer sender, Peer receiver, String fileContent, String fileName) implements Sendable {
+    
+    @Override
+    public EDataType getType() {
+        return EDataType.PullFileRequest;
+    }
+
+    @Override
+    public Peer getSender() {
+        return this.sender;
+    }
+
+    @Override
+    public Peer getReceiver() {
+        return this.receiver;
+    }
+
+    @Override
+    public byte[] getMessage() {
+        String response =
+            "{\"sendFile\":\"" + fileContent + "\"" +
+            "," + 
+            "\"fileName\":\"" + fileName + "\"" +
+            "," + 
+            "\"ipPort\":\"" + sender.ipAddress() + ":" + sender.port() + "\"}";
+        return response.getBytes();
+    }
+
+}

src/main/java/java/src/Sending/Data/Sendable.java

@@ -0,0 +1,18 @@
+/**
+ * @author Aaron Moser
+ */
+
+package java.src.Sending.Data;
+
+import java.src.Peers.Peer;
+
+/**
+ * An instance of this class represents data to send to another peer, by also providing information
+ * about this peer and the receiving peer.
+ */
+public interface Sendable {
+    public EDataType getType();
+    public Peer getSender();
+    public Peer getReceiver();
+    public byte[] getMessage();
+}

src/main/java/java/src/Sending/SenderThread.java

@@ -0,0 +1,59 @@
+/**
+ * @author Aaron Moser
+ */
+
+package java.src.Sending;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.src.Terminatable;
+import java.src.Sending.Data.Sendable;
+
+public class SenderThread extends Thread implements Terminatable {
+
+    private DatagramSocket ds = null;
+    private SendingQueue sendingQueue = null;
+
+    public SenderThread(DatagramSocket ds, SendingQueue sendingQueue) {
+        this.ds = ds;
+        this.sendingQueue = sendingQueue;
+    }
+
+    private boolean senderThreadRunning = true;
+
+    @Override
+    public void run() {
+        while (senderThreadRunning) {
+            try {
+                Sendable dataToSent = sendingQueue.take();
+
+                byte[] fileData = dataToSent.getMessage();
+
+                if (fileData != null) {
+                    String receiverIpAddress = dataToSent.getReceiver().ipAddress();
+                    int receiverPort = dataToSent.getReceiver().port();
+                    int fileDataLength = fileData.length;
+
+                    DatagramPacket dp =
+                        new DatagramPacket(fileData, fileDataLength, InetAddress.getByName(receiverIpAddress), receiverPort);
+                    ds.send(dp);
+                }
+            } catch (UnknownHostException e) {
+                System.out.println("Error, host is unknown or unreachable.");
+            } catch (IOException e) {
+                System.out.println("Error, wasn't able to send data, because of problem with socket.");
+            } catch (InterruptedException e) {
+                System.out.println("Error, sending queue was interrupted. Terminating (this) sending thread..");
+                this.terminate();
+            }
+        }
+    }
+
+    public void terminate() {
+        senderThreadRunning = false;
+    }
+}
+

src/main/java/java/src/Sending/SendingQueue.java

@@ -0,0 +1,10 @@
+/**
+ * @author Aaron Moser
+ */
+
+package java.src.Sending;
+
+import java.src.Sending.Data.Sendable;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class SendingQueue extends LinkedBlockingQueue<Sendable> {}