Apache Mina UDP客户端：java.net.PortUnreachableException

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java.net.PortUnreachableException

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我制作了一个简单的ApacheMinaUDP服务器并运行了它。然后，我使用telnet 127.0.0.1 3450检查它是否正在侦听，并且连接没有被拒绝，因此服务器肯定可以工作

客户端由以下文件组成

这是下面的主要类别：

public static void main(String[] args) {
    System.out.println("started");
    NioDatagramConnector connector = new NioDatagramConnector();

    connector.setHandler(new PacketHandler());
    ConnectFuture cf = connector.connect(new InetSocketAddress("127.0.0.1", 3450));
}

这是PacketHandler类的一部分：

@Override
public void sessionOpened(IoSession s) {
    System.out.println("opened " + s.getId() + " " + s.getLocalAddress().toString() + " " + s.getRemoteAddress().toString());
    byte[] data = new byte[]{(byte) 0x01};
    System.out.println("Sending " + data.length);
    IoBuffer buffer = IoBuffer.allocate(data.length);
    buffer.put(data);
    buffer.flip();
    s.write(buffer);
}

当客户端运行时，我得到以下错误：

started
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
created 1
opened 1 /127.0.0.1:56777 /127.0.0.1:3450
Sending 1
java.net.PortUnreachableException
    at sun.nio.ch.DatagramDispatcher.read0(Native Method)
    at sun.nio.ch.DatagramDispatcher.read(DatagramDispatcher.java:43)
    at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
    at sun.nio.ch.IOUtil.read(IOUtil.java:197)
    at sun.nio.ch.DatagramChannelImpl.read(DatagramChannelImpl.java:560)
    at org.apache.mina.transport.socket.nio.NioProcessor.read(NioProcessor.java:311)
    at org.apache.mina.transport.socket.nio.NioProcessor.read(NioProcessor.java:45)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:702)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:668)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:657)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$600(AbstractPollingIoProcessor.java:67)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:1121)
    at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
closed 1

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服务器还记录连接，当客户端运行时，不会记录任何连接。但是，当从我的终端运行

telnet 127.0.0.1 3450

时，会在服务器日志中记录连接。显然，客户端实际上没有连接。

Telnet无法连接到UDP。因此，您正在使用Telnet测试TCP服务器，但没有任何结果

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检查代码，您可以将其粘贴到此处

Telnet不能证明UDP端口的任何特性。它测试TCP端口。您连接的端口上没有打开UDP套接字。@Michaël当然有，回答正确。