Projet_JAVA_P2P_STRI2A/src/clientP2P/ClientManagementUDP.java

package clientP2P;
import exception.InternalError;
import exception.ProtocolError;
import exception.SizeError;
import exception.TransmissionError;
import exception.VersionError;
import remoteException.EmptyDirectory;
import remoteException.InternalRemoteError;
import remoteException.NotFound;
import remoteException.ProtocolRemoteError;
import remoteException.VersionRemoteError;
import java.net.UnknownHostException;
import java.util.Scanner;
import java.net.InetAddress;
import java.net.DatagramSocket;
import java.net.SocketException;
import java.io.IOException;
import java.nio.file.Files;
import java.io.File;
import protocolP2P.ProtocolP2PDatagram;
import protocolP2P.Payload;
import protocolP2P.RequestResponseCode;
import protocolP2P.FileList;
import protocolP2P.FilePart;
import protocolP2P.LoadRequest;

/** Implementation of P2P-JAVA-PROJECT CLIENT
 * @author	Louis Royer
 * @author	Flavien Haas
 * @author	JS Auge
 * @version	1.0
 */
public class ClientManagementUDP implements Runnable {
	private String baseDirectory;
	private int UDPPort;
	private String host;
	private DatagramSocket socket;



	/** Constructor for UDP implementation, with baseDirectory and UDPPort parameters.
	 * @param baseDirectory	the root directory where files are stored
	 * @param host	hostname of the server
	 * @param UDPPort	the server will listen on this port
	 */
	public ClientManagementUDP(String baseDirectory, String host, int UDPPort) {
		this.baseDirectory = baseDirectory;
		this.host = host;
		this.UDPPort = UDPPort;
		try {
			socket = new DatagramSocket();
		} catch (SocketException e) {
			System.err.println("Error: No socket available.");
			System.exit(-1);
		}
	}

	/** Implementation of Runnable
	 */
	public void run() {
		try {
			String[] list = listDirectory();
			System.out.println("Files present on the server:");
			for(String listItem: list) {
				System.out.println(listItem);
			}
			System.out.println("Name of the file to download:");
			Scanner scanner = new Scanner(System.in);
			String f = scanner.nextLine();
			download(f);
			System.out.println("File sucessfully downloaded");
		} catch (EmptyDirectory e) {
			System.err.println("Error: Server has no file in directory");
		} catch (InternalError e) {
			System.err.println("Error: Client internal error");
		} catch (UnknownHostException e) {
			System.err.println("Error: Server host is unknown");
		} catch (IOException e) {
			System.err.println("Error: Request cannot be send or response cannot be received");
		} catch (TransmissionError e) {
			System.err.println("Error: Message received is too big");
		} catch (ProtocolError e) {
			System.err.println("Error: Cannot decode server’s response");
		} catch (VersionError e) {
			System.err.println("Error: Server’s response use bad version of the protocol");
		} catch (SizeError e) {
			System.err.println("Error: Cannot handle this packets because of internal representation limitations of numbers on the client");
		} catch (InternalRemoteError e) {
			System.err.println("Error: Server internal error");
		} catch (ProtocolRemoteError e) {
			System.err.println("Error: Server cannot decode client’s request");
		} 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");
		}
	}

	/** Try to download a file
	 * @param filename	name of the file to download
	 * @throws	NotFound
	 * @throws	InternalError
	 * @throws	UnknownHostException
	 * @throws	IOException
	 * @throws	TransmissionError
	 * @throws	ProtocolError
	 * @throws	VersionError
	 * @throws	SizeError
	 * @throws	InternalRemoteError
	 * @throws	ProtocolRemoteError
	 * @throws	VersionRemoteError
	 */
	private void download(String filename) throws 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 {
			Payload p = ProtocolP2PDatagram.receive(socket).getPayload();
			assert p instanceof FilePart : "This payload must be instance of FilePart";
			if (!(p instanceof FilePart)) {
				throw new InternalError();
			} else {
				FilePart fp = (FilePart)p;
				if (!fp.getFilename().equals(filename)) {
					System.err.println("Error: wrong file received");
					throw new ProtocolError();
				}
				if (fp.getOffset() != 0 || fp.getPartialContent().length != fp.getTotalSize()) {
					System.err.println("offset: " + fp.getOffset() + " ; content.length: " + fp.getPartialContent().length + " ; totalSize: " + fp.getTotalSize());
					System.err.println("Error: cannot handle partial files (not implemented)");
					throw new InternalError();
				}
				try {
					Files.write(new File(baseDirectory + filename).toPath(), fp.getPartialContent());
				} catch (IOException e) {
					System.err.println("Error: cannot write file (" + baseDirectory + filename + ")");
				}
			}
		} catch (EmptyDirectory e) {
		throw new ProtocolError();
	}

	}

	/** list server’s directory content
	 * @return	list of files
	 * @throws	InternalError
	 * @throws	UnknowHostException
	 * @throws	IOException
	 * @throws	TransmissionError
	 * @throws	ProtocolError
	 * @throws	VersionError
	 * @throws	SizeError
	 * @throws	EmptyDirectory
	 * @throws	InternalRemoteError
	 * @throws	ProtocolRemoteError
	 * @throws	VersionRemoteError
	 */
	private String[] listDirectory() throws EmptyDirectory, InternalError, UnknownHostException, IOException, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
		ProtocolP2PDatagram d = new ProtocolP2PDatagram(new Payload(RequestResponseCode.LIST_REQUEST));
		d.send(socket, host, UDPPort);
		try {
			Payload p = ProtocolP2PDatagram.receive(socket).getPayload();
			assert p instanceof FileList : "This payload must be instance of Filelist";
			if (!(p instanceof FileList)) {
				throw new InternalError();
			} else {
				return ((FileList)p).getFileList();
			}
		} catch (NotFound e) {
			throw new ProtocolError();
		}
	}
}