Java发起HTTPS连接遇ConnectException超时，求排查方案

测试代码 #

public static void main(String[] args) throws UnknownHostException, IOException {
    
    /*None of these worked:
    System.setProperty("http.proxyHost", "prxgm.aknet.akb");
    System.setProperty("http.proxyPort", "8080");
    System.setProperty("https.proxyHost", "prxgm.aknet.akb");
    System.setProperty("https.proxyPort", "8080");
    System.setProperty("java.net.useSystemProxies", "true");
    */
    
    /*neither this helped:
    ProxySearch proxySearch = new ProxySearch();
    proxySearch.addStrategy(Strategy.OS_DEFAULT); 
    ProxySelector proxySelector = proxySearch.getProxySelector(); 
    ProxySelector.setDefault(proxySelector); 
    */

    String host = //"services.gradle.org"
            "www.yapikredi.com.tr"
            ;
    Integer port = 443;
    SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
    SSLSocket sslsocket = (SSLSocket) sslsocketfactory
      .createSocket(host, port);
    InputStream in = sslsocket.getInputStream();
    OutputStream out = sslsocket.getOutputStream();

    out.write(1);
    while (in.available() > 0) {
        System.out.print(in.read());
    }

    System.out.println("Secured connection performed successfully");
}

运行异常 #

Exception in thread "main" java.net.ConnectException: Connection timed out: connect
at java.base/sun.nio.ch.Net.connect0(Native Method)
at java.base/sun.nio.ch.Net.connect(Net.java:579)
at java.base/sun.nio.ch.Net.connect(Net.java:568)
at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:576)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327)
at java.base/java.net.Socket.connect(Socket.java:666)
at java.base/sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:304)
at java.base/sun.security.ssl.SSLSocketImpl.<init>(SSLSocketImpl.java:163)
at java.base/sun.security.ssl.SSLSocketFactoryImpl.createSocket(SSLSocketFactoryImpl.java:88)
at SSLDeneme.main(SSLDeneme.java:25)

已尝试的解决方案 #

• 在Eclipse运行配置中添加代理参数：-Dhttp.proxyHost=prxgm.aknet.akb -Dhttp.proxyPort=8080 -Dhttps.proxyHost=prxgm.aknet.akb -Dhttps.proxyPort=8080
• 在代码中直接设置代理系统属性（代码中已注释）
• 使用Proxy-Vole库自动获取系统代理

网络诊断结果 #

tracert 结果 #

Tracing route to www.yapikredi.com.tr [193.254.228.224] over a maximum of 30 hops:
  1    <1 ms    <1 ms    <1 ms  10.215.144.1
  2     1 ms    <1 ms    <1 ms  10.215.252.3
  3     1 ms    <1 ms    <1 ms  10.243.226.61
  4     *        *        *     Request timed out.
  5     *        *        *     Request timed out.
  6     *        *        *     Request timed out.
  7     *        *        *     Request timed out.
  8     *        *        *     Request timed out.
  9     *        *        *     Request timed out.
 10     *        *        *     Request timed out.
 11     *        *        *     Request timed out.
 12     *        *        *     Request timed out.
 13     *        *        *     Request timed out.
 14     *        *        *     Request timed out.
 15     *        *        *     Request timed out.
 16     *        *        *     Request timed out.
 17     *        *        *     Request timed out.
 18     *        *        *     Request timed out.
 19     *        *        *     Request timed out.
 20     *        *        *     Request timed out.
 21     *        *        *     Request timed out.
 22     *        *        *     Request timed out.
 23     *        *        *     Request timed out.
 24     *        *        *     Request timed out.
 25     *        *        *     Request timed out.
 26     *        *        *     Request timed out.
 27     *        *        *     Request timed out.
 28     *        *        *     Request timed out.
 29     *        *        *     Request timed out.
 30     *        *        *     Request timed out.

Trace complete.

ping 结果 #

ping www.yapikredi.com.tr
Pinging www.yapikredi.com.tr [193.254.228.224] with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 193.254.228.224:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

补充说明 #

• 浏览器可正常访问https://www.yapikredi.com.tr
• telnet连接目标站点超时，但无需代理的站点（如https://www.akbank.com）可正常连接，相关代码运行无问题
• 推测问题出在Java代理配置，但已尝试方案均无效

请问还有哪些排查方向可以尝试？

内容的提问来源于stack exchange，提问作者Cagin Uludamar