使用Mina客户端如何和服务端建立长连接，给个示例

好的，以下是一个示例：

客户端代码：

import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.core.service.IoConnector;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.transport.socket.nio.NioSocketConnector;

public class MyClient {
    private static final String HOSTNAME = "localhost"; // 服务端地址
    private static final int PORT = 12345; // 服务端端口号

    public static void main(String[] args) {
        IoConnector connector = new NioSocketConnector();
        connector.setConnectTimeoutMillis(30000); // 连接超时时间

        connector.setHandler(new MyClientHandler()); // 设置消息处理器

        ConnectFuture future = connector.connect(new InetSocketAddress(HOSTNAME, PORT)); // 连接服务端
        future.awaitUninterruptibly(); // 等待连接完成

        IoSession session = future.getSession(); // 获取会话

        session.getCloseFuture().awaitUninterruptibly(); // 等待会话关闭
        connector.dispose(); // 关闭连接器
    }
}

服务端代码：

import java.net.InetSocketAddress;

import org.apache.mina.core.service.IoAcceptor;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.transport.socket.nio.NioSocketAcceptor;

public class MyServer {
    private static final int PORT = 12345; // 监听端口号

    public static void main(String[] args) throws Exception {
        IoAcceptor acceptor = new NioSocketAcceptor(); // 创建连接器
        acceptor.setHandler(new MyServerHandler()); // 设置消息处理器
        acceptor.bind(new InetSocketAddress(PORT)); // 绑定监听端口号

        System.out.println("Server started on port " + PORT);

        acceptor.dispose(); // 关闭连接器
    }
}