我已经读过，可以在不竞争握手的情况下获取证书数据，这对于减少时间是可取的。下面的代码用于获取证书信息，但代码完成了 ssl 握手。如果任何一位网络编程专家可以告诉我如何在不完成 ssl 握手的情况下获取远程主机的证书信息？
package com.kushal.security;
import java.security.cert.Certificate;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
public class JavaSSLCertificate {
public static void main(String[] argv) throws Exception {
int port = 443;
String hostname = "gmail.com";
SSLSocketFactory factory = HttpsURLConnection
.getDefaultSSLSocketFactory();
System.out.println("Creating a SSL Socket For "+hostname+" on port "+port);
SSLSocket socket = (SSLSocket) factory.createSocket(hostname, port);
socket.startHandshake();
System.out.println("Handshaking Complete");
Certificate[] serverCerts = socket.getSession().getPeerCertificates();
System.out.println("Retreived Server's Certificate Chain");
System.out.println(serverCerts.length + "Certifcates Found\n\n\n");
for (int i = 0; i < serverCerts.length; i++) {
Certificate myCert = serverCerts[i];
System.out.println("====Certificate:" + (i+1) + "====");
System.out.println("-Public Key-\n" + myCert.getPublicKey());
System.out.println("-Certificate Type-\n " + myCert.getType());
System.out.println();
}
socket.close();
}
}