Add mulithreaded UDP client

This commit is contained in:
Louis Royer 2020-03-12 17:52:31 +01:00
parent e46be57b8c
commit 733767c4de
4 changed files with 697 additions and 99 deletions

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@ -0,0 +1,297 @@
package clientP2P;
import java.util.List;
import java.util.ArrayList;
import java.net.DatagramSocket;
import protocolP2P.ProtocolP2PPacketUDP;
import protocolP2P.Payload;
import protocolP2P.LoadRequest;
import protocolP2P.FilePart;
import exception.InternalError;
import remoteException.EmptyDirectory;
import remoteException.EmptyFile;
import exception.ProtocolError;
import remoteException.InternalRemoteError;
import remoteException.VersionRemoteError;
import exception.TransmissionError;
import remoteException.ProtocolRemoteError;
import exception.VersionError;
import exception.SizeError;
import remoteException.NotFound;
import java.nio.file.Files;
import java.io.File;
import java.nio.file.Paths;
import java.io.IOException;
/** Class to download file parts on udp.
* @author Louis Royer
* @author Flavien Haas
* @author JS Auge
* @version 1.0
*/
public class ClientDownloadPartUDP implements Runnable {
private List<Long> toDoTasks;
private List<Long> pendingTasks;
private List<Long> tasksDone;
private volatile boolean tasksListsLock;
private volatile boolean stop;
private volatile boolean failed;
private String filename;
private DatagramSocket socket;
private volatile boolean noTask;
private String partsSubdir;
private static final long MAX_PARTIAL_SIZE = 4096;
/** Constructor with filename, socket, and part subdir
* @param filename name of file to download
* @param socket socket to use
* @param partsSubdir directory to store .part files
*/
public ClientDownloadPartUDP(String filename, DatagramSocket socket, String partsSubdir) {
this.partsSubdir = partsSubdir;
this.filename = filename;
this.socket = socket;
stop = false;
failed = false;
pendingTasks = new ArrayList<>();
toDoTasks = new ArrayList<>();
tasksDone = new ArrayList<>();
noTask = true;
tasksListsLock = false;
}
/** True if thread has failed to get a file.
* @return true if thread has failed to get a file
*/
public boolean hasFailed() {
return failed;
}
/** Asks to stop thread.
* @throws InterruptedException
*/
public synchronized void setStop() throws InterruptedException {
stop = true;
this.notifyAll();
}
/** Runnable implementation */
public void run() {
while(!stop) {
try {
doTasks();
} catch(InterruptedException e) {
try {
setStop();
} catch (InterruptedException e2) {
}
}
}
System.err.println("Closing socket");
socket.close();
}
/** Get list of offsets that have not be downloaded if failed, else
* empty list.
* @return list of offsets
*/
public List<Long> getFailed() {
List<Long> ret = new ArrayList<>();
if (failed) {
ret.addAll(pendingTasks);
ret.addAll(toDoTasks);
}
return ret;
}
/** Get list of downloaded file parts offset, then clear this list.
* @return list of offsets
* @throws InterruptedException
*/
public List<Long> getDone() throws InterruptedException {
if (tasksDone.size() == 0) {
return new ArrayList<>();
} else {
synchronized (this) {
while(tasksListsLock) {
this.wait();
}
tasksListsLock = true;
List<Long> ret = new ArrayList<>(tasksDone);
tasksDone.clear();
tasksListsLock = false;
this.notifyAll();
return ret;
}
}
}
/** Adds offset of files parts to download.
* @param task offset to download
* @throws InterruptedException
*/
public synchronized void assignTask(Long task) throws InterruptedException {
synchronized(this) {
while(tasksListsLock) {
this.wait();
}
tasksListsLock = true;
toDoTasks.add(task);
noTask = false;
tasksListsLock = false;
this.notifyAll();
}
}
/** Send one request and wait for one response. Blocks when no task.
* @throws InterruptedException
*/
public synchronized void doTasks() throws InterruptedException {
while(noTask && !stop) {
this.wait();
}
if (!stop) {
try {
Long offset = toDoTasks.get(0);
ProtocolP2PPacketUDP p = reqPart(offset);
if (p == null) {
stop = true;
}
failed = downloadPart(p);
if (failed) {
System.err.println("Error: DownloadPart failed.");
stop = true;
} else if (toDoTasks.isEmpty()) {
noTask = true;
}
} catch (IndexOutOfBoundsException e) {
noTask = true;
}
}
}
public ProtocolP2PPacketUDP reqPart(Long offset) {
System.err.println("New request: "+ offset);
// maintain tracking of tasks
if (toDoTasks.contains(offset)) {
try {
synchronized (this) {
while(tasksListsLock) {
this.wait();
}
tasksListsLock = true;
toDoTasks.remove(offset);
pendingTasks.add(offset);
tasksListsLock = false;
this.notifyAll();
}
} catch(InterruptedException e) {
System.err.println("Error: reqPart interruptedException");
return null;
}
} else {
System.err.println("Error: reqPart (offset " + offset + " not in toDoTasks)");
return null;
}
// send request
try {
ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, offset.longValue(), MAX_PARTIAL_SIZE));
d.sendRequest((Object)socket);
return d;
} catch (InternalError e) {
System.err.println("Error: reqPart internalError");
return null;
} catch (IOException e) {
e.printStackTrace();
System.err.println("Error: reqPart ioexception");
return null;
}
}
public boolean downloadPart(ProtocolP2PPacketUDP d) {
if (d == null) {
System.err.println("Error: downloadPart -> d is null.");
return true;
}
try {
Payload p = d.receiveResponse().getPayload();
assert p instanceof FilePart : "This payload must be instance of FilePart";
if (!(p instanceof FilePart)) {
System.err.println("Error: cannot get size.");
return true;
} else {
FilePart fp = (FilePart)p;
if (!fp.getFilename().equals(filename)) {
System.err.println("Error: wrong file received: `" + fp.getFilename() + "`");
return true;
}
Long offset = Long.valueOf(fp.getOffset());
if (pendingTasks.contains(offset)) {
try {
Files.write(new File(partsSubdir + filename + "_" + offset + ".part").toPath(), fp.getPartialContent());
} catch (IOException e) {
System.err.println("Error: cannot write file (" + partsSubdir + filename + "_" + offset + ".part)");
}
} else {
System.err.println("Error: wrong file part received.");
return true;
}
try {
synchronized(this) {
while(tasksListsLock) {
this.wait();
}
tasksListsLock = true;
pendingTasks.remove(offset);
tasksDone.add(offset);
tasksListsLock = false;
this.notifyAll();
}
} catch(InterruptedException e) {
System.err.println("Error: DownloadPart Interrupted exception");
return true;
}
}
} catch (EmptyDirectory e) {
System.err.println("Error: empty directory.");
return true;
} catch (EmptyFile e) {
System.err.println("Error: downloadPart emptyFile");
// TODO: use more specific errors
return true;
} catch (ProtocolError e) {
System.err.println("Error: downloadPart protocolError");
return true;
} catch (InternalRemoteError e) {
System.err.println("Error: downloadPart internalRemoteError");
return true;
} catch (VersionRemoteError e) {
System.err.println("Error: downloadPart versionRemoteError");
return true;
} catch (ProtocolRemoteError e) {
System.err.println("Error: downloadPart protocolRemoteError");
return true;
} catch (TransmissionError e) {
System.err.println("Error: downloadPart transmissionError");
return true;
} catch (VersionError e) {
System.err.println("Error: downloadPart versionError");
return true;
} catch (SizeError e) {
System.err.println("Error: downloadPart sizeError");
return true;
} catch (NotFound e) {
System.err.println("Error: downloadPart notFound");
return true;
} catch (IOException e) {
System.err.println("Error: downloadPart ioexception");
return true;
} catch (InternalError e) {
System.err.println("Error: downloadPart internalError");
return true;
}
return false;
}
}

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@ -0,0 +1,372 @@
package clientP2P;
import clientP2P.ClientDownloadPartUDP;
import tools.HostItem;
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import remoteException.EmptyDirectory;
import remoteException.EmptyFile;
import remoteException.VersionRemoteError;
import remoteException.ProtocolRemoteError;
import remoteException.NotFound;
import remoteException.InternalRemoteError;
import protocolP2P.HashAlgorithm;
import protocolP2P.HashResponse;
import protocolP2P.HashRequest;
import protocolP2P.ProtocolP2PPacketUDP;
import protocolP2P.Payload;
import exception.ProtocolError;
import exception.InternalError;
import exception.TransmissionError;
import exception.SizeError;
import exception.VersionError;
import protocolP2P.FilePart;
import protocolP2P.LoadRequest;
import java.io.IOException;
import java.nio.file.Files;
import java.io.File;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.nio.file.StandardCopyOption;
/** Class to download file from udp
* @author Louis Royer
* @author Flavien Haas
* @author JS Auge
* @version 1.0
*/
public class ClientDownloadUDP implements Runnable {
private List<HostItem> hostList;
private String filename;
private byte[] hash512;
private List<ClientDownloadPartUDP> sockList = new ArrayList<ClientDownloadPartUDP>();
private List<Long> offsetsToAsk = new ArrayList<Long>();
private List<Long> offsetsPending = new ArrayList<Long>();
private boolean stop;
private long size;
private static final long MAX_PARTIAL_SIZE = 4096;
private String partsSubdir;
private String dirStorage;
private boolean success = false;
/** Constructor with parameters: filename, list of hosts, parts subdirectory and dirStorage
* @param filename name of file to download
* @param hostList list of servers
* @param partsSubdir directory to store .part files
* @param dirStorage directory to write assembled file
*/
public ClientDownloadUDP(String filename, List<HostItem> hostList, String partsSubdir, String dirStorage) {
this.partsSubdir = partsSubdir;
this.dirStorage = dirStorage;
this.filename = filename;
this.hostList = hostList;
this.stop = false;
}
/** Asks thread to stop
*/
public void setStop() {
stop = true;
}
/** Runnable implementation
*/
public void run() {
try {
init();
if (stop) {
System.err.println("File is smaller than part max size.");
hostList.get(0).closeUDPSocket();
} else {
System.err.println("File is bigger than part max size.");
purgeList();
initThreads();
while(!stop) {
checkTasksStatus();
assignTasks();
}
}
System.err.println("Reassembling file parts.");
reassembleFile();
} catch(InternalError e) {
System.err.println("Error while downloading file. Aborting.");
} finally {
stopTasks();
}
}
/** Starts threads for each server in hostList.
*/
private void initThreads() {
for(HostItem hostItem: hostList) {
sockList.add(new ClientDownloadPartUDP(filename, hostItem.getUDPSocket(), partsSubdir));
}
for(ClientDownloadPartUDP c: sockList) {
Thread t = new Thread(c);
t.start();
}
System.err.println("Threads initialized");
}
/** Remove tasks from failed threads. Update done status.
* @throws InternalError
*/
private void checkTasksStatus() throws InternalError {
List<ClientDownloadPartUDP> sockListCpy = new ArrayList<>(sockList);
for(ClientDownloadPartUDP c: sockListCpy) {
if (c.hasFailed() == true) {
sockList.remove(c);
offsetsPending.removeAll(c.getFailed());
offsetsToAsk.addAll(c.getFailed());
}
try {
offsetsPending.removeAll(c.getDone());
} catch (InterruptedException e) {
throw new InternalError();
}
}
System.err.println("Task check status: " + offsetsToAsk.size() + " to asks, " + offsetsPending.size() + " pending");
if (offsetsToAsk.isEmpty() && offsetsPending.isEmpty()) {
stop = true;
}
if (sockList.size() == 0) {
System.err.println("No thread working");
throw new InternalError();
}
}
/** Assign tasks randomly to threads.
* @throws InternalError
*/
private void assignTasks() throws InternalError {
Random rand = new Random();
for(long offset : offsetsToAsk) {
try {
sockList.get(rand.nextInt(sockList.size())).assignTask(offset);
offsetsPending.add(offset);
System.err.println("Assigned task "+ offset);
} catch(InterruptedException e) {
throw new InternalError();
}
}
offsetsToAsk.removeAll(offsetsPending);
}
/** Stop threads */
private void stopTasks() {
for(ClientDownloadPartUDP c : sockList) {
try {
c.setStop();
} catch (InterruptedException e) {}
}
}
/** Get hashsum from server.
* @param hostItem server to ask hash
* @return hash512sum
* @throws InternalError
*/
private byte[] getHashSum512(HostItem hostItem) throws InternalError {
byte[] hash;
HashAlgorithm[] hashesAlgo = new HashAlgorithm[1];
hashesAlgo[0] = HashAlgorithm.SHA512;
ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new HashRequest(filename, hashesAlgo));
try {
d.sendRequest((Object)hostItem.getUDPSocket());
try {
Payload pHash = d.receiveResponse().getPayload();
assert pHash instanceof HashResponse : "This payload must be instance of HashResponse";
if (!(pHash instanceof HashResponse)) {
throw new InternalError();
} else {
hash = ((HashResponse)pHash).getHash(HashAlgorithm.SHA512);
}
} catch (EmptyDirectory e) {
hash = new byte[0];
} catch (NotFound e) {
hash = new byte[0];
// TODO: use more specific errors
} catch (EmptyFile e) {
throw new InternalError();
} catch (ProtocolError e) {
throw new InternalError();
} catch (InternalRemoteError e) {
throw new InternalError();
} catch (VersionRemoteError e) {
throw new InternalError();
} catch (ProtocolRemoteError e) {
throw new InternalError();
} catch (TransmissionError e) {
throw new InternalError();
} catch (VersionError e) {
throw new InternalError();
} catch (SizeError e) {
throw new InternalError();
}
return hash;
} catch (IOException e) {
throw new InternalError();
}
}
/** Removes servers not owning the correct file to download from list.
* This is done by comparing hash512sum.
* @throws InternalError
*/
private void purgeList() throws InternalError {
List<HostItem> blackList = new ArrayList<HostItem>();
boolean first = false;
byte[] hashsum;
for(HostItem host: hostList) {
// already have hashsum from 1st server
if (!first) {
first = true;
continue;
}
// ask hashsum
hashsum = getHashSum512(host);
if (!Arrays.equals(hash512, hashsum)) {
blackList.add(host);
}
}
// purge list
for(HostItem host: blackList) {
hostList.remove(host);
}
System.err.println("Host list purge: done");
}
/** Getter for hash512sum
* @return hash512sum
*/
public byte[] getHashSum512() {
return hash512;
}
/** Initialize infos about file to download (size, hash512sum, partslist to dl).
* Also download first partfile (to get size).
* @throws InternalError
*/
private void init() throws InternalError {
// get size
setSize();
// get hashsum from 1st server in list
hash512 = getHashSum512(hostList.get(0));
if (hash512.length == 0) {
System.err.println("Error: no hash512sum support.");
throw new InternalError();
}
// Add tasks
if (!stop) {
for(long i=MAX_PARTIAL_SIZE; i<size;i+=MAX_PARTIAL_SIZE) {
offsetsToAsk.add(Long.valueOf(i));
}
System.err.println("Adding tasks: done");
}
}
/** Set size of file to download. Also download first file part.
* @throws InternalError
*/
private void setSize() throws InternalError {
ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
try {
d.sendRequest((Object)hostList.get(0).getUDPSocket());
try {
Payload p = d.receiveResponse().getPayload();
assert p instanceof FilePart : "This payload must be instance of FilePart";
if (!(p instanceof FilePart)) {
System.err.println("Error: cannot get size.");
throw new InternalError();
} else {
FilePart fp = (FilePart)p;
if (!fp.getFilename().equals(filename)) {
System.err.println("Error: wrong file received: `" + fp.getFilename() + "`");
throw new ProtocolError();
}
if (fp.getOffset() == 0) {
try {
Files.write(new File(partsSubdir + filename + "_0.part").toPath(), fp.getPartialContent());
} catch (IOException e) {
System.err.println("Error: cannot write file (" + partsSubdir + filename + "_0.part)");
}
size = fp.getTotalSize();
if (fp.getPartialContent().length == size) {
stop = true;
}
} else {
System.err.println("Error: wrong file part received.");
throw new InternalError();
}
}
} catch (EmptyDirectory e) {
System.err.println("Error: empty directory.");
throw new InternalError();
} catch (EmptyFile e) {
// TODO: use more specific errors
throw new InternalError();
} catch (ProtocolError e) {
throw new InternalError();
} catch (InternalRemoteError e) {
throw new InternalError();
} catch (VersionRemoteError e) {
throw new InternalError();
} catch (ProtocolRemoteError e) {
throw new InternalError();
} catch (TransmissionError e) {
throw new InternalError();
} catch (VersionError e) {
throw new InternalError();
} catch (SizeError e) {
throw new InternalError();
} catch (NotFound e) {
throw new InternalError();
}
} catch (IOException e) {
throw new InternalError();
}
}
/** Success getter.
* @return true when file have successfully been reassembled.
*/
public boolean getSuccess() {
return success;
}
private void reassembleFile() {
boolean firstPart = true;
boolean abort = false;
long nextOffset = 0;
do {
if (firstPart) {
System.err.println("Reassembling: First part");
try {
// create file
Files.copy(new File(partsSubdir + filename + "_" + nextOffset + ".part").toPath(), new File(dirStorage + filename).toPath(), StandardCopyOption.REPLACE_EXISTING);
nextOffset = (new File(dirStorage + filename)).length();
firstPart = false;
} catch (IOException e) {
System.err.println("Reassembling: aborting on first part");
abort = true;
}
} else if (nextOffset >= size) {
success = true;
System.err.println("Reassembling: success");
} else {
// append to file
try {
Files.write(new File(dirStorage + filename).toPath(), Files.readAllBytes(new File(partsSubdir + filename + "_" + nextOffset + ".part").toPath()), StandardOpenOption.APPEND);
nextOffset = (new File(dirStorage + filename)).length();
} catch (IOException e) {
abort = true;
System.err.println("Aborting: bad number " + nextOffset);
}
}
} while((!success) && (!abort));
}
}

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@ -34,6 +34,7 @@ import protocolP2P.HashRequest;
import protocolP2P.HashResponse;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import clientP2P.ClientDownloadUDP;
/** Implementation of P2P-JAVA-PROJECT CLIENT
* @author Louis Royer
@ -43,6 +44,7 @@ import java.security.NoSuchAlgorithmException;
*/
public class ClientManagementUDP implements Runnable {
private String baseDirectory;
private String partsSubdir;
private List<HostItem> hostList;
/** Constructor for UDP implementation, with baseDirectory and UDPPort parameters.
@ -50,9 +52,10 @@ public class ClientManagementUDP implements Runnable {
* @param host hostname of the server
* @param UDPPort the server will listen on this port
*/
public ClientManagementUDP(String baseDirectory, List<HostItem> hostList) {
public ClientManagementUDP(String baseDirectory, List<HostItem> hostList, String partsSubdir) {
this.baseDirectory = baseDirectory;
this.hostList = hostList;
this.partsSubdir = partsSubdir;
}
/** Implementation of Runnable
@ -115,106 +118,32 @@ public class ClientManagementUDP implements Runnable {
* @throws EmptyFile
*/
private void download(String filename) throws EmptyFile, NotFound, InternalError, UnknownHostException, IOException, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
byte[] hash512;
final long MAX_PARTIAL_SIZE = 4096;
HashAlgorithm[] hashesAlgo = new HashAlgorithm[1];
hashesAlgo[0] = HashAlgorithm.SHA512;
ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new HashRequest(filename, hashesAlgo));
d.sendRequest((Object)hostList.get(0).getUDPSocket());
ClientDownloadUDP downLoader = new ClientDownloadUDP(filename, hostList, partsSubdir, baseDirectory);
Thread t = new Thread(downLoader);
t.start();
try {
Payload pHash = d.receiveResponse().getPayload();
assert pHash instanceof HashResponse : "This payload must be instance of HashResponse";
if (!(pHash instanceof HashResponse)) {
t.join();
if (downLoader.getSuccess()) {
byte[] hash512 = downLoader.getHashSum512();
if (!Arrays.equals(hash512, computeHashsum(filename, HashAlgorithm.SHA512))) {
System.err.println("Error: Hashsum does not match");
System.err.println("Computed checksum:");
byte[] c = computeHashsum(filename, HashAlgorithm.SHA512);
for (byte b: c) {
System.err.print(String.format("%02X", b));
}
System.err.println("");
System.err.println("Received checksum:");
for (byte b: hash512) {
System.err.print(String.format("%02X", b));
}
System.err.println("");
throw new InternalError();
}
} else {
throw new InternalError();
} else {
hash512 = ((HashResponse)pHash).getHash(HashAlgorithm.SHA512);
if (hash512.length == 0) {
System.err.println("Error: server do not support sha512 hashes");
throw new InternalError();
}
}
} catch (EmptyDirectory e) {
System.err.println("Error: empty directory, but request was not LIST_REQUEST");
throw new ProtocolError();
}
d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
d.sendRequest((Object)hostList.get(0).getUDPSocket());
boolean fileFullyWritten = false;
long offset = 0;
do {
try {
Payload p = d.receiveResponse().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: `" + fp.getFilename() + "`");
throw new ProtocolError();
}
if (fp.getOffset() == 0) {
System.err.println("Receiving first partialContent");
// first partialContent
// increment offset
offset = fp.getPartialContent().length;
/* write first partialContent */
try {
Files.write(new File(baseDirectory + filename).toPath(), fp.getPartialContent());
} catch (IOException e) {
System.err.println("Error: cannot write file (" + baseDirectory + filename + ")");
}
// next partialContentRequest
if (offset != fp.getTotalSize()) {
System.err.println("Sending following request with offset: " + offset + " maxpartialsize: " + MAX_PARTIAL_SIZE);
d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, offset, MAX_PARTIAL_SIZE));
d.sendRequest((Object)hostList.get(0).getUDPSocket());
} else {
fileFullyWritten = true;
}
} else if (offset == fp.getOffset()){
System.err.println("Receiving following partialContent (offset: " + offset + ")");
// following
// increment offset
offset += fp.getPartialContent().length;
/* write following partialContent at end of file*/
try {
Files.write(Paths.get(baseDirectory + filename), fp.getPartialContent(), StandardOpenOption.APPEND);
} catch (IOException e) {
System.err.println("Error: cannot write file (" + baseDirectory + filename + ")");
}
if (offset >= fp.getTotalSize()) {
fileFullyWritten = true;
} else {
// next partialContentRequest
d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, offset, MAX_PARTIAL_SIZE));
d.sendRequest((Object)hostList.get(0).getUDPSocket());
}
} else {
System.err.println("offset: " + fp.getOffset() + " ; content.length: " + fp.getPartialContent().length + " ; totalSize: " + fp.getTotalSize());
System.err.println("Error: cannot handle non-consecutive partial files (not implemented)");
throw new InternalError();
}
}
} catch (EmptyDirectory e) {
throw new ProtocolError();
}
} while(!fileFullyWritten);
if (!Arrays.equals(hash512, computeHashsum(filename, HashAlgorithm.SHA512))) {
System.err.println("Error: Hashsum does not match");
System.err.println("Computed checksum:");
byte[] c = computeHashsum(filename, HashAlgorithm.SHA512);
for (byte b: c) {
System.err.print(String.format("%02X", b));
}
System.err.println("");
System.err.println("Received checksum:");
for (byte b: hash512) {
System.err.print(String.format("%02X", b));
}
System.err.println("");
} catch (InterruptedException e) {
throw new InternalError();
}
}

View File

@ -35,7 +35,7 @@ public class ClientP2P {
case "udp":
case "2" :
System.out.println("Starting with UDP");
ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.hostList);
ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.hostList, c.directories.getDataHomeDirectory() + c.parts + "/");
t = new Thread(cmudp);
break;
case "TCP":