我有一个更大的java代码块，但重要的一行是：

public static String tcp(String hostName, Number port, Number connectionTimeOutMs, Number readTimeOutMs, String message) {
    String errmsg = "";
    try (
        Socket socket = new Socket();
    ) {
        Inet4Address address = (Inet4Address) Inet4Address.getByName(hostName);
        System.out.println("IP address:" + address.getHostAddress());
        socket.connect(new InetSocketAddress(address, port.intValue()), connectionTimeOutMs.intValue());
        socket.setSoTimeout(readTimeOutMs.intValue());

当我在表单中提供ip地址时 "45.79.112.203" 或者 "tcpbin.com" ，代码给出 SocketTimeoutException .
在后一种情况下

System.out.println("IP address:" + address.getHostAddress());

提供正确的ip地址，以便正确解析主机名；匹配什么 ping tcpbin.com 返回。
我希望能够使用ipv4地址（字符串格式）或主机名调用函数。
我做错什么了？为什么即使有60000毫秒的高超时，套接字也无法建立连接？
笔记： tcpbin.com 是一个“echo”服务器，用于测试套接字连接。它仅用作示例，不应成为问题的原因。
请尝试以下操作：

echo "Text to send to TCP" | nc tcpbin.com 4242

你应该拿回刚才发来的那条线。
在tcp（）函数中，我以 Number 对象，因为java代码是通过java inter-op和javascript从空手道测试框架调用的。javascript的类型 Number ，但不是 int 或者 double .

更新：
这里是一个简单的tcp服务器tcpserver.java

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class TcpServer {
    public static void main(String[] args) {
        System.out.println("Listening on port 4242");
        ServerSocket listener = null;
        try {
            do {
                listener = new ServerSocket(4242);
                Socket other = listener.accept();
                System.out.println(">>> got a new connection from "
                        + other.getInetAddress().toString() + " <<<");
                other.getOutputStream().write("Blah blah".getBytes());
                other.close();
                listener.close();
            } while (true);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

===
这里有一个测试类来测试 tcp() 功能。如果host！=本地主机。
testtcpfunction.java文件：

import java.io.*;
import java.net.*;

public class TestTcpFunction {
    public static void main(String[] args) {
        String sendMessage = "Blah blah";

        String host = (args.length==0)
                    ? "localhost"
                    : "tcpbin.com";

        String result = tcp(host, 4242, 30000, 30000, sendMessage);
        System.out.println("result = " + result);
        System.out.println("matches = " + result.equals(sendMessage));
    }

    public static String tcp(String hostName, Number port, Number connectionTimeOutMs, Number readTimeOutMs, String message) {
        String errmsg = "";
        try (
            Socket socket = new Socket();
        ) {
            Inet4Address address = (Inet4Address) Inet4Address.getByName(hostName);
            System.out.println("trying to connect to:" + address.getHostAddress());
            socket.connect(new InetSocketAddress(address, port.intValue()), connectionTimeOutMs.intValue()); // <<< times out if not localhost
            socket.setSoTimeout(readTimeOutMs.intValue());

            try (
                PrintWriter out = new PrintWriter(socket.getOutputStream(), true); // autoflush
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            ) {
                out.print(message);
                StringBuilder sb = new StringBuilder();
                String line;
                boolean addNewline = false;

                while ((line = in.readLine()) != null) {
                    if (addNewline)
                        sb.append('\n');
                    sb.append(line);
                    if (line.lastIndexOf("</response>") >= 0)
                        break;

                    addNewline = true;
                }

                return sb.toString(); // The xml may not be well formed, for instance missing </response>
            } finally {}

        } catch (UnknownHostException e) {
            errmsg = "Unknown host " + hostName;
        } catch (SocketTimeoutException e) {
            errmsg = "Socket connection timeout (before connection got established)";
        } catch (SocketException e) {
            errmsg = "Socket error: " + e.getMessage();
        } catch (IOException e) {
            errmsg = "Couldn't get I/O for the connection to " + hostName;
        } catch (Exception e) {
            errmsg = "Unknown socket error " + e.getMessage();
        }

        System.err.println(errmsg);
        return "<Error> function tcp (Utils.java): " + errmsg + "</Error>";
    }
}

===
用javac编译两者。然后用启动服务器 java TcpServer . 下次跑步 java TestTcpFunction 在不同的shell中，没有参数。
第一次（与本地主机）它应该正常工作。然后再次运行，但使用任何参数，如 java TestTcpFunction 1 这次我尝试连接时超时。
代码已经在我的机器上构建和测试。