我目前有一个桌面服务器,它是在非阻塞模式下使用niojava库编写的。您可以在这里找到完整的服务器项目。我还为测试目的创建了一个非阻塞nio客户机。你可以在这里找到那个项目。最后,该服务器应该用于android即时消息应用程序。我将客户端和服务器都建立在发送“数据包”进行通信的思想上。我的意思是,包类的引用被打包到字节缓冲区中,并通过套接字通道发送。然后在另一端反序列化并执行它们。
我当前的问题是:我的测试客户机在连接到服务器时似乎会断开连接。我知道问题是客户端的,因为当我使用telnet通过命令行连接到服务器时,连接不会断开。奇怪的是,服务器正在打印与它的连接已经建立,但是当客户端断开连接时,它从不说连接已经丢失/终止。
这是处理所有nio网络的客户机类。。。
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.baiocchi.enigma.client.test.Engine;
import org.baiocchi.enigma.client.test.databundle.DataBundle;
import org.baiocchi.enigma.client.test.packet.Packet;
import org.baiocchi.enigma.client.test.ui.LogType;
import org.baiocchi.enigma.client.test.ui.Logger;
public class Client extends Thread {
private boolean running;
private final int port;
private SocketChannel connection;
private final ByteBuffer buffer;
private Selector selector;
private List<DataBundle> pendingDataBundleQue;
public Client(int port) {
this.port = port;
pendingDataBundleQue = new LinkedList<DataBundle>();
buffer = ByteBuffer.allocate(8192);
try {
selector = initiateSelector();
connection = initiateConnection();
} catch (IOException e) {
e.printStackTrace();
}
}
private Selector initiateSelector() throws IOException {
return SelectorProvider.provider().openSelector();
}
private SocketChannel initiateConnection() throws IOException {
SocketChannel connection = SocketChannel.open();
connection.configureBlocking(false);
connection.connect(new InetSocketAddress("localhost", port));
connection.register(selector, SelectionKey.OP_CONNECT);
return connection;
}
public SocketChannel getConnection() {
return connection;
}
@Override
public void start() {
running = true;
super.start();
}
public void addToPendingDataBundleQue(DataBundle bundle) {
synchronized (pendingDataBundleQue) {
pendingDataBundleQue.add(bundle);
}
}
@Override
public void run() {
while (running) {
System.out.println("loop");
try {
synchronized (pendingDataBundleQue) {
System.out.println("Checking for que changes.");
if (!pendingDataBundleQue.isEmpty()) {
System.out.println("Found que change.");
SelectionKey key = connection.keyFor(selector);
key.interestOps(SelectionKey.OP_WRITE);
}
}
System.out.println("Selecting keys");
selector.select();
System.out.println("Creating selected keys list.");
Iterator<SelectionKey> selectedKeys = selector.selectedKeys().iterator();
while (selectedKeys.hasNext()) {
System.out.println("scrolling through list");
SelectionKey key = (SelectionKey) selectedKeys.next();
selectedKeys.remove();
if (!key.isValid()) {
System.out.println("invalid");
continue;
} else if (key.isConnectable()) {
System.out.println("connect");
establishConnection(key);
} else if (key.isReadable()) {
System.out.println("read");
readData(key);
} else if (key.isWritable()) {
System.out.println("write");
writeData(key);
}
}
} catch (IOException | ClassNotFoundException e) {
e.printStackTrace();
}
}
System.out.println("Broke loop");
}
private void writeData(SelectionKey key) throws IOException {
synchronized (pendingDataBundleQue) {
SocketChannel connection = (SocketChannel) key.channel();
for (DataBundle bundle : pendingDataBundleQue) {
System.out.println("sent packet");
connection.write(bundle.getBuffer());
}
pendingDataBundleQue.clear();
if (pendingDataBundleQue.isEmpty()) {
Logger.write("All packets sent.", LogType.CLIENT);
connection.keyFor(selector).interestOps(SelectionKey.OP_READ);
}
}
}
private void readData(SelectionKey key) throws IOException, ClassNotFoundException {
buffer.clear();
int byteCount;
try {
byteCount = connection.read(buffer);
} catch (IOException e) {
Logger.writeException("Connenction closed.", LogType.CLIENT);
connection.close();
key.cancel();
return;
}
if (byteCount == -1) {
Logger.writeException("Connection error. Attempting to terminate connection.", LogType.CLIENT);
key.channel().close();
key.cancel();
}
Engine.getInstance().getPacketProcessor().processData(buffer);
}
private void establishConnection(SelectionKey key) throws IOException {
SocketChannel channel = (SocketChannel) key.channel();
try {
if (channel.finishConnect()) {
Logger.write("Connection established.", LogType.CLIENT);
key.interestOps(SelectionKey.OP_READ);
}
} catch (IOException e) {
Logger.write("Failed to establish connection.", LogType.CLIENT);
key.channel().close();
key.cancel();
return;
}
}
}
这里是处理所有服务器网络的服务器类。
package org.baiocchi.enigma.server.network;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.ArrayList;
import java.util.Iterator;
import org.baiocchi.enigma.server.Engine;
import org.baiocchi.enigma.server.databundle.DataBundle;
import org.baiocchi.enigma.server.ui.components.logger.LogType;
import org.baiocchi.enigma.server.ui.components.logger.Logger;
public class Server extends Thread {
private boolean running;
private final int port;
private ServerSocketChannel server;
private final ByteBuffer buffer;
private Selector selector;
private ArrayList<DataBundle> pendingDataBundleQue;
public Server(int port) {
this.port = port;
buffer = ByteBuffer.allocate(8192);
pendingDataBundleQue = new ArrayList<DataBundle>();
try {
server = ServerSocketChannel.open().bind(new InetSocketAddress("localhost", port));
server.configureBlocking(false);
selector = SelectorProvider.provider().openSelector();
server.register(selector, SelectionKey.OP_ACCEPT);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void start() {
running = true;
super.start();
}
public void terminateConnection(SocketChannel channel) {
SelectionKey key = channel.keyFor(selector);
try {
key.channel().close();
key.cancel();
} catch (IOException e) {
e.printStackTrace();
}
}
public void addToPendingPacketQue(DataBundle bundle) {
synchronized (pendingDataBundleQue) {
pendingDataBundleQue.add(bundle);
}
}
@Override
public void run() {
while (running) {
try {
synchronized (pendingDataBundleQue) {
if (!pendingDataBundleQue.isEmpty()) {
for (DataBundle bundle : pendingDataBundleQue) {
SelectionKey key = bundle.getChannel().keyFor(selector);
key.interestOps(SelectionKey.OP_WRITE);
}
}
}
selector.select();
Iterator<SelectionKey> selectedKeys = selector.selectedKeys().iterator();
while (selectedKeys.hasNext()) {
SelectionKey key = (SelectionKey) selectedKeys.next();
selectedKeys.remove();
if (!key.isValid()) {
continue;
} else if (key.isAcceptable()) {
acceptConnection(key);
} else if (key.isReadable()) {
readData(key);
} else if (key.isWritable()) {
writeData(key);
}
}
} catch (IOException | ClassNotFoundException e) {
Logger.writeException("Internal server error.", LogType.SERVER);
Logger.writeException(e.getMessage(), LogType.SERVER);
}
}
}
private void writeData(SelectionKey key) throws IOException {
DataBundle bundle = null;
for (DataBundle b : pendingDataBundleQue) {
if (b.getChannel().equals((SocketChannel) key.channel())) {
bundle = b;
break;
}
}
if (bundle == null) {
Logger.writeException("Couldn't find out bound packet in list.", LogType.SERVER);
return;
}
SocketChannel connection = bundle.getChannel();
connection.write(bundle.getBuffer());
connection.keyFor(selector).interestOps(SelectionKey.OP_READ);
pendingDataBundleQue.remove(bundle);
}
private void readData(SelectionKey key) throws IOException, ClassNotFoundException {
SocketChannel channel = (SocketChannel) key.channel();
buffer.clear();
int byteCount;
try {
byteCount = channel.read(buffer);
} catch (IOException e) {
Logger.writeException("Connenction terminated.", LogType.SERVER);
channel.close();
key.cancel();
return;
}
if (byteCount == -1) {
Logger.writeException("Connection error. Terminating connection.", LogType.SERVER);
key.channel().close();
key.cancel();
return;
}
Engine.getInstance().getPacketProcessor().processData(buffer, channel);
}
private void acceptConnection(SelectionKey key) throws IOException {
ServerSocketChannel channel = (ServerSocketChannel) key.channel();
SocketChannel connection = channel.accept();
connection.configureBlocking(false);
connection.register(selector, SelectionKey.OP_READ);
Logger.write("Connection established.", LogType.SERVER);
}
}
提前谢谢!
1条答案
按热度按时间cig3rfwq1#
这里没有证据表明客户端已断开连接。如果有,其中一个块将在服务器上执行:
我的结论是客户端根本没有断开连接。
我注意到您有一个名为
Logger.writeException()
您从不使用它来记录异常,并且您的日志消息是背对背的:catch (IOException )
指示一个连接错误,您应该在该错误上记录实际的异常,并且readBytes == -1
表示“连接已终止”,这不是错误。我还注意到一个
return
在客户端的相应代码中。nb关闭频道取消按键。你不需要自己取消。