（更新代码） 我正在努力让客户与服务器进行通信（我已经制作了简单的客户端 - 服务器应用程序，比如聊天室）。通信已创建，但存在很大的延迟（我将坐标从客户端发送到服务器）。它超过10秒（有时甚至更多）。可能是什么问题呢？ 客户：
public class GameComponent extends Canvas implements Runnable {
private static final long serialVersionUID = 1L;
private static final int WIDTH = 320;
private static final int HEIGHT = 240;
private static final int SCALE = 2;
private boolean running;
private JFrame frame;
Thread thread;
public static final int GRID_W = 16;
public static final int GRID_H = 16;
private Socket socket;
private DataInputStream reader;
private DataOutputStream writer;
private HashMap<Integer, OtherPlayer> oPlayers;
private ArrayList<OtherPlayer> opList;
private int maxID = 1;
private int ID;
Player player;
public GameComponent() {
//GUI code..
oPlayers = new HashMap<Integer, OtherPlayer>(); //Hash map to be able to get players by their ID's
opList = new ArrayList<OtherPlayer>(); //And an array list for easier drawing
setUpNetworking();
start();
}
public void start() {
if (running)
return;
running = true;
thread = new Thread(this);
player = new Player(GRID_W * 2, GRID_H * 2);
thread.start();
}
public void stop() {
if (!running)
return;
running = false;
}
public void run() { //The main loop, ticks 60 times every second
long lastTime = System.nanoTime();
double nsPerTick = 1000000000D / 60D;
int frames = 0;
int ticks = 0;
long lastTimer = System.currentTimeMillis();
double delta = 0;
while (running) {
long now = System.nanoTime();
delta += (now - lastTime) / nsPerTick;
lastTime = now;
boolean shouldRender = true;
while (delta >= 1) {
ticks++;
tick(delta);
delta -= 1;
shouldRender = true;
}
try {
Thread.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (shouldRender) {
frames++;
render();
}
if (System.currentTimeMillis() - lastTimer >= 1000) {
lastTimer += 1000;
frames = 0;
ticks = 0;
}
}
}
private void tick(double delta) { //main logic
player.move();
try {
writer.writeInt(ID); //I send the player data here (id, x, y)
writer.writeInt(player.getX());
writer.writeInt(player.getY());
writer.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
private void render(Graphics2D g2d) {
//rendering the stuff
for (OtherPlayer i : opList) { //drawing a black rectangle for every other player
g2d.fillRect(i.getX(), i.getY(), GRID_W, GRID_H);
}
}
private void render() {
//more rendering...
}
public static void main(String[] args) {
new GameComponent();
}
class TKeyListener implements KeyListener {
//movement methods...
}
private void setUpNetworking() { //This is where I make my message reader and data IO
try {
socket = new Socket("127.0.0.1", 5099);
reader = new DataInputStream(socket.getInputStream());
writer = new DataOutputStream(socket.getOutputStream());
Thread rT = new Thread(new msgReader());
rT.start();
} catch (Exception e) {
e.printStackTrace();
}
}
class msgReader implements Runnable { //where I read messages
public void run() {
try {
ID = reader.readInt(); //when I connect, I get an id from the server
while(true) { //my main loop
int oid = reader.readInt(); //get the read data id
int ox, oy;
ox = reader.readInt(); //get the read player's x and y
oy = reader.readInt();
if (oid != ID){ //If not reading myself
if (oPlayers.containsKey(oid)) { //If a player with this id exists
OtherPlayer op = (OtherPlayer) oPlayers.get(oid);
op.setX(ox); //set it's x, y
op.setY(oy);
} else { //if it doesn't exist, create him
OtherPlayer op = new OtherPlayer(ox, oy);
opList.add(op);
oPlayers.put(oid, op);
}
}
maxID = reader.readInt(); //Allways read the highest current id from server
}
} catch(Exception ex) {
ex.printStackTrace();
}
}
}
}
服务器：
public class ServerBase {
ServerSocket serverSocket;
ArrayList<DataOutputStream> clients;
private int id = 1;
SyncSend ss = new SyncSend();
class ClientHandler implements Runnable {
private Socket soc;
private DataInputStream reader;
private int x;
private int y;
private int id;
private boolean run = true;
public ClientHandler(Socket s) {
soc = s;
try {
reader = new DataInputStream(soc.getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
public void run() {
try {
while (run) {
id = reader.readInt();
x = reader.readInt();
y = reader.readInt();
if (id == 2)
System.out.println("x: " + x + " y: " + y);
int[] tmb = {id, x, y};
ss.sendEveryone(tmb);
}
} catch (Exception e) {
run = false;
clients.remove(this);
}
}
}
class SyncSend {
public synchronized void sendEveryone(int[] a) throws SocketException {
ArrayList<DataOutputStream> cl = (ArrayList<DataOutputStream>) clients.clone();
Iterator<DataOutputStream> it = cl.iterator();
while(it.hasNext()){
try {
DataOutputStream writer = (DataOutputStream) it.next();
writer.writeInt(a[0]);
writer.writeInt(a[1]);
writer.writeInt(a[2]);
writer.writeInt(id-1);
writer.flush();
} catch (Exception ex) {
throw new SocketException();
}
}
}
}
public void init() {
clients = new ArrayList<DataOutputStream>();
try {
serverSocket = new ServerSocket(5099);
while(true) {
Socket clientSocket = serverSocket.accept();
DataOutputStream clientWriter = new DataOutputStream(clientSocket.getOutputStream());
clients.add(clientWriter);
clientWriter.writeInt(id);
id++;
Thread t = new Thread(new ClientHandler(clientSocket));
t.start();
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new ServerBase().init();
}
}
导致延误的原因是什么？我一直在寻找几个小时的原因，但没有成功。
答案 0 :(得分：2)
您很可能需要在客户端调用flush()。即使这不是你当前的问题，也许这是一个好主意。
Streams可能会缓冲其内容，这意味着他们可能无法将数据发送到目的地（无论是磁盘还是通过电线连接到服务器），您拨打的时间write（或writeInt in这个案例）。相反，他们可能要等到他们获得足够数量的数据才能使转移“值得”。如果他们不以这种方式行事，他们最终会做出许多效率低下的小转会。所有这一切的缺点是，您可能需要调用flush告诉流您已完成数据发送一段时间，并且流应该继续并启动传输。
答案 1 :(得分：0)
尝试将代码放到几个线程中，然后调用线程，我的意思是你不需要等待每个套接字，只需同时运行所有这些...或类似的东西：）
例如在端口扫描程序中，您应该使用许多线程来加速搜索......
答案 2 :(得分：0)
请注意，您对ss.sendEveryone(tmb)对ss的呼叫已同步。我假设这是一个static变量，它包含对所有客户端的引用。这意味着如果有多个客户端同时发送数据，那么很多同时会发生sendEveryone的调用，并且它们将排队等待其他客户端完成，然后这些线程可以返回并再次从客户端读取更多数据。
作为诊断练习，您可能希望删除此来电并查看是否仍有问题。