Verify that the mailbox can be served

MAVEN

<! - Verify the mailbox is available -> 
        <dependency> 
            <groupId> dnsjava </ groupId> 
            <artifactId> dnsjava </ artifactId> 
            <Version> 2.1.1 </ Version> 
        </ dependency>

JAVA code

package com.jm.mail.tools;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import org.apache.commons.lang.ArrayUtils;
importorg.apache.commons.lang.StringUtils;
 Import org.apache.commons.lang.builder.CompareToBuilder;
 Import org.xbill.DNS.Lookup;
 Import org.xbill.DNS.MXRecord;
 Import org.xbill.DNS.Record;
 Import org.xbill.DNS.TextParseException;
 Import org.xbill.DNS.Type; 


public  class MailValid { 

    public  static  void main (String [] args) { 
                System.out.println ( new new . MailValid () Valid ( "a111aaaaaaaaaaa @ 163 .com "," jootmir.org " )); 


    } 

    / ** 
     * verify mailbox exists 
     * <br> 
     * to read the IO, will cause the thread to block
     * 
     * @Param toMail 
     * To verify that the mailbox 
     * @param Domain 
     * issuing domain name verification request (the current site of the domain name, you can specify any) 
     * @return 
     * mailbox is up 
     * / 
    public  static  boolean ! Valid (toMail String, String Domain) {
         IF (StringUtils.isBlank (toMail) || StringUtils.isBlank (Domain)) return  to false ;
         IF (! StringUtils.contains (toMail, '@')) return  to false ; 
        String Host = toMail.substring (toMail.indexOf ( '@') +. 1 );
         IF(host.equals (Domain)) return  to false ; 
        the Socket Socket = new new the Socket ();
         the try {
             // find mx records 
            the Record [] = MXrecords new new the Lookup (Host, Type.MX) .run ();
             IF (ArrayUtils.isEmpty (MXrecords)) return  to false ;
             // mail server address 
            String mxHost = ((The MXRecord) MXrecords [0 ]) the getTarget () toString ();..
             IF (mxRecords.length>. 1) { // prioritizing 
                List <Record > = arrRecords new new the ArrayList <the Record> ( );
                Collections.addAll(arrRecords, mxRecords);
                Collections.sort(arrRecords, new Comparator<Record>() {

                    public int compare(Record o1, Record o2) {
                        return new CompareToBuilder().append(((MXRecord)o1).getPriority(), ((MXRecord)o2).getPriority()).toComparison();
                    }

                });
                mxHost = ((MXRecord)arrRecords.get(0)).getTarget().toString();
            }
            // 开始smtp
            socket.connect(new InetSocketAddress(mxHost, 25));
            BufferedReader the BufferedReader = new new the BufferedReader ( new new the InputStreamReader ( new new BufferedInputStream (Socket.getInputStream ()))); 
            BufferedWriter, BufferedWriter = new new BufferedWriter, ( new new the OutputStreamWriter (Socket.getOutputStream ()));
             // timeout (ms) 
            Long timeout = 6000 ;
             // sleep time segment (50 ms) 
            int sleepSect = 50 ; 

            // connection (the server is ready) 
            iF (getResponseCode (timeout, sleepSect, BufferedReader) 220 =! {)
                 return  to false ; 
            } 

            // 握手
            bufferedWriter.write("HELO " + domain + "\r\n");
            bufferedWriter.flush();
            if(getResponseCode(timeout, sleepSect, bufferedReader) != 250) {
                return false;
            }
            // 身份
            bufferedWriter.write("MAIL FROM: <check@" + domain + ">\r\n");
            bufferedWriter.flush();
            if(getResponseCode(timeout, sleepSect, bufferedReader) != 250) {
                return false;
            }
            // 验证
            bufferedWriter.write("RCPT TO: <" + toMail + ">\r\n");
            bufferedWriter.flush();
            if(getResponseCode(timeout, sleepSect, bufferedReader) != 250) {
                return false;
            }
            // 断开
            bufferedWriter.write("QUIT\r\n");
            bufferedWriter.flush();
            return true;
        } catch (NumberFormatException e) {
            e.printStackTrace();
        } catch (TextParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            try {
                socket.close();
            } catch (IOException e) {
            }
        }
        return false;
    }


    private static int getResponseCode(long timeout, int sleepSect, BufferedReader bufferedReader) throws InterruptedException, NumberFormatException, IOException {
        int code = 0;
        for(long i = sleepSect; i < timeout; i += sleepSect) {
            Thread.sleep(sleepSect);
            if(bufferedReader.ready()) {
                String outline = bufferedReader.readLine();
                // FIXME 读完……
                while(bufferedReader.ready())
                    /*System.out.println(*/bufferedReader.readLine()/*)*/;
                /*System.out.println(outline);*/
                code = Integer.parseInt(outline.substring(0, 3));
                break;
            }
        }
        return code;
    }
}