java 验证邮件是否可用

附代码：

      package com.bjike.goddess.intromanage.excel;

      import org.apache.xmlbeans.impl.util.Base64;

      import javax.net.ssl.SSLSocketFactory;
      import java.io.*;
      import java.net.Socket;
      import java.net.SocketTimeoutException;
      import java.util.ArrayList;
      import java.util.List;
      import java.util.concurrent.CountDownLatch;

      public class MailPasswordCheck implements Runnable {

             private String userName;
             private String password;
             private String success = "update";

      public MailPasswordCheck(String userName, String password) {
           this.userName = userName;
           this.password = password;
      }

private final static String host = "contacts.163.com";
private final static int port = 443;
private final static int TIMEOUT = 3;
private final static int repeat = 3;
private final static String path = "/.well-known/carddav";
private final static SSLSocketFactory ssf = (SSLSocketFactory) SSLSocketFactory.getDefault();
private final static String xmlData = "<?xml version=\"1.0\"?> <d:propfind xmlns:d=\"DAV:\" xmlns:cs=\"http://calendarserver.org/ns/\"> <d:prop> <d:displayname /> <d:getetag /> </d:prop> </d:propfind>";
private final CountDownLatch runCount = new CountDownLatch(3);


private String checkPassword() throws IOException {

    Socket socket = ssf.createSocket(host, port);
    socket.setSoTimeout(TIMEOUT * 1000);
    PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())));
    out.println("PROPFIND " + path + " HTTP/1.1");
    out.println("Host: " + host);
    String userCredentials = userName + ":" + password;
    String basicAuth = "Basic " + new String(Base64.encode(userCredentials.getBytes()));
    String authorization = "Authorization: " + basicAuth;
    out.println(authorization.trim());
    out.println("Content-Length: " + xmlData.length());
    out.println("Content-Type: text/xml");
    out.println("Depth: 1");
    out.println();
    out.println(xmlData);
    out.flush();

    BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

    List<String> counts = new ArrayList<>(1);
    if (counts.size() == 0) {
        try {
            counts.add(in.readLine());
        } catch (SocketTimeoutException st) {
            return "timeout";
        }
    }
    in.close();
  //        out.close();
 //        socket.close();
    if (counts.get(0).contains("207")) {
        return "true";
    } else {
        return "false";
    }
}


@Override
public void run() {
    for (int i = 0; i < repeat; i++) {
        try {
            String result = checkPassword();
            if (result.equals("true")) {
                success = "success";
                for(int j =0;j<=runCount.getCount()+1;j++){
                    runCount.countDown();
                }
                break;
            } else if (result.equals("false")) {
                success = "update";
                for(int j =0;j<=runCount.getCount()+1;j++){
                    runCount.countDown();
                }
                break;
            } else {
                success = "timeout";
                runCount.countDown();
                System.out.println("repeating ...");
                continue;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public String getSuccess() {
    try {
        runCount.await();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return success;
}


public static void main(String[] args) {
    MailPasswordCheck mailPasswordCheck = new MailPasswordCheck("xx.com", "xx");
    new Thread(mailPasswordCheck).start();
    System.out.println(mailPasswordCheck.getSuccess());
}   }