Add empty file error code

doc/protocol.md

@@ -38,6 +38,7 @@ x bytes: [64-xx: PAYLOAD]
 	- `INTERNAL ERROR` (0xC2)
 	- `EMPTY DIRECTORY` (0xC3)
 	- `NOT FOUND` (0xC4)
+	- `EMPTY FILE` (0xC5)
 
 ### List
 Payload size for list request is always zero.

src/clientP2P/ClientManagementUDP.java

@@ -4,6 +4,7 @@ import exception.ProtocolError;
 import exception.SizeError;
 import exception.TransmissionError;
 import exception.VersionError;
+import remoteException.EmptyFile;
 import remoteException.EmptyDirectory;
 import remoteException.InternalRemoteError;
 import remoteException.NotFound;
@@ -92,7 +93,9 @@ public class ClientManagementUDP implements Runnable {
 		} catch (VersionRemoteError e) {
 			System.err.println("Error: Server cannot decode this version of the protocol");
 		} catch (NotFound e) {
-			System.err.println("Error: Server have not this file in directory");
+			System.err.println("Error: Server has not this file in directory");
+		} catch (EmptyFile e) {
+			System.err.println("Error: File is empty");
 		}
 	}
 
@@ -109,8 +112,9 @@ public class ClientManagementUDP implements Runnable {
 	 * @throws	InternalRemoteError
 	 * @throws	ProtocolRemoteError
 	 * @throws	VersionRemoteError
+	 * @throws	EmptyFile
 	 */
-	private void download(String filename) throws NotFound, InternalError, UnknownHostException, IOException, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
+	private void download(String filename) throws EmptyFile, NotFound, InternalError, UnknownHostException, IOException, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
 		ProtocolP2PDatagram d = new ProtocolP2PDatagram((Payload) new LoadRequest(filename));
 		d.send(socket, host, UDPPort);
 		try {
@@ -168,6 +172,8 @@ public class ClientManagementUDP implements Runnable {
 			}
 		} catch (NotFound e) {
 			throw new ProtocolError();
+		} catch (EmptyFile e) {
+			throw new ProtocolError();
 		}
 	}
 }

src/protocolP2P/FileList.java

@@ -66,7 +66,9 @@ public class FileList extends Payload {
 		int size = 8;
 		for (String s : fileList) {
 			size += s.length();
+			size += 1;
 		}
+		size -=1;
 		byte[] datagram = new byte[size]; // java initialize all to zero
 		// set request/response code
 		datagram[RequestResponseCode.RRCODE_POSITION] = requestResponseCode.codeValue;

src/protocolP2P/FilePart.java

@@ -32,7 +32,7 @@ public class FilePart extends Payload {
 		super(RequestResponseCode.LOAD_RESPONSE);
 		/* asserts to help debugging */
 		assert totalSize >= 0 : "totalSize cannot be negative";
-		assert partialContent.length != 0 : "partialContent.length cannot be zero"; 
+		assert partialContent.length != 0 : "partialContent.length cannot be zero, see RRCode.EMPTY_FILE"; 
 		assert totalSize >= partialContent.length : "totalSize must be greater than partialContent.length";
 		assert offset >= 0 : "offset cannot be negative";
 		assert filename != null : "filename is required";

src/protocolP2P/ProtocolP2PDatagram.java

@@ -9,6 +9,7 @@ import remoteException.InternalRemoteError;
 import remoteException.NotFound;
 import remoteException.ProtocolRemoteError;
 import remoteException.VersionRemoteError;
+import remoteException.EmptyFile;
 import protocolP2P.Payload;
 import protocolP2P.RequestResponseCode;
 import protocolP2P.LoadRequest;
@@ -108,8 +109,9 @@ public class ProtocolP2PDatagram {
 	 * @throws	EmptyDirectory
 	 * @throws	NotFound
 	 * @throws	IOException
+	 * @throws	EmptyFile
 	 */
-	public static ProtocolP2PDatagram receive(DatagramSocket socket) throws NotFound, EmptyDirectory, InternalRemoteError, VersionRemoteError, ProtocolRemoteError, TransmissionError, ProtocolError, VersionError, InternalError, SizeError, IOException {
+	public static ProtocolP2PDatagram receive(DatagramSocket socket) throws EmptyFile, NotFound, EmptyDirectory, InternalRemoteError, VersionRemoteError, ProtocolRemoteError, TransmissionError, ProtocolError, VersionError, InternalError, SizeError, IOException {
 		// reception
 		byte[] datagram = new byte[4096];
 		DatagramPacket reception = new DatagramPacket(datagram, datagram.length);
@@ -131,6 +133,8 @@ public class ProtocolP2PDatagram {
 					throw new EmptyDirectory();
 				case NOT_FOUND :
 					throw new NotFound();
+				case EMPTY_FILE:
+					throw new EmptyFile();
 				default :
 					return p;
 			}

src/protocolP2P/RequestResponseCode.java

@@ -20,7 +20,8 @@ public enum RequestResponseCode {
 	PROTOCOL_ERROR(CodeType.ERROR, (byte)0xC1),
 	INTERNAL_ERROR(CodeType.ERROR, (byte)0xC2),
 	EMPTY_DIRECTORY(CodeType.ERROR, (byte)0xC3),
-	NOT_FOUND(CodeType.ERROR, (byte)0xC4);
+	NOT_FOUND(CodeType.ERROR, (byte)0xC4),
+	EMPTY_FILE(CodeType.ERROR, (byte)0xC5);
 	
 	public final CodeType codeType;
 	public final byte codeValue;

src/remoteException/EmptyFile.java

@@ -0,0 +1,4 @@
+package remoteException;
+public class EmptyFile extends Exception {
+	private static final long serialVersionUID = 11L;
+}

src/serverP2P/ServerManagementUDP.java

@@ -22,6 +22,8 @@ import remoteException.InternalRemoteError;
 import remoteException.NotFound;
 import remoteException.ProtocolRemoteError;
 import remoteException.VersionRemoteError;
+import remoteException.EmptyFile;
+import java.util.Arrays;
 
 
 /** Implementation of P2P-JAVA-PROJECT VERSION 1.0 protocol for UDP.
@@ -70,10 +72,18 @@ public class ServerManagementUDP implements Runnable {
 							String filename = ((LoadRequest)p).getFilename();
 							try {
 								byte[] load = Files.readAllBytes(Paths.get(baseDirectory + filename));
-								try {
-									(new ProtocolP2PDatagram((Payload)(new FilePart(filename, load.length, 0, load)))).send(socket, pd);
-								} catch (Exception e2) {
-									System.err.println(e2);
+								if (Arrays.binarySearch(fileList, filename) >= 0) {
+									try {
+										if (load.length == 0) {
+											(new ProtocolP2PDatagram(new Payload(RequestResponseCode.EMPTY_FILE))).send(socket, pd);
+										} else {
+											(new ProtocolP2PDatagram((Payload)(new FilePart(filename, load.length, 0, load)))).send(socket, pd);
+										}
+									} catch (Exception e2) {
+										System.err.println(e2);
+									}
+								} else {
+									throw new IOException(); // to send a NOT_FOUND in the catch block
 								}
 							} catch (IOException e) {
 								try {
@@ -112,6 +122,7 @@ public class ServerManagementUDP implements Runnable {
 			} catch (VersionError e) {
 			} catch (InternalError e) {
 			} catch (SizeError e) {
+			} catch (EmptyFile e) {
 			}
 		}
 	}