在前面的章节查询电子邮件和读取电子邮件，我们通过授权凭证（用户名和密码）以及主机，连接到您的邮箱中存储时。相反，我们可以配置属性有主机，并告诉您的自定义的Authenticator实例的会话。这示于下面的例子：

创建Java类

我们将修改CheckingMails.java 请先阅读 章查询电子邮件 这章。其内容如下所述：

package com.yiibai;

import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.NoSuchProviderException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Store;

public class CheckingMails {

   public static void check(String host, String storeType, String user,
      String password) 
   {
      try {

      // create properties field
      Properties properties = new Properties();

      properties.put("mail.pop3s.host", host);
      properties.put("mail.pop3s.port", "995");
      properties.put("mail.pop3s.starttls.enable", "true");

      // Setup authentication, get session
      Session emailSession = Session.getInstance(properties,
         new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
               return new PasswordAuthentication(
                  "manishapatil3may@gmail.com", "manisha123");
            }
         });
      // emailSession.setDebug(true);

      // create the POP3 store object and connect with the pop server
      Store store = emailSession.getStore("pop3s");

      store.connect();

      // create the folder object and open it
      Folder emailFolder = store.getFolder("INBOX");
      emailFolder.open(Folder.READ_ONLY);

      // retrieve the messages from the folder in an array and print it
      Message[] messages = emailFolder.getMessages();
      System.out.println("messages.length---" + messages.length);

      for (int i = 0, n = messages.length; i < n; i++) {
         Message message = messages[i];
         System.out.println("---------------------------------");
         System.out.println("Email Number " + (i + 1));
         System.out.println("Subject: " + message.getSubject());
         System.out.println("From: " + message.getFrom()[0]);
         System.out.println("Text: " + message.getContent().toString());
      }

      // close the store and folder objects
      emailFolder.close(false);
      store.close();

      } catch (NoSuchProviderException e) {
         e.printStackTrace();
      } catch (MessagingException e) {
         e.printStackTrace();
      } catch (Exception e) {
         e.printStackTrace();
      }
   }

   public static void main(String[] args) {

      String host = "pop.gmail.com";// change accordingly
      String mailStoreType = "pop3";
      String username = "abc@gmail.com";// change accordingly
      String password = "*****";// change accordingly

      check(host, mailStoreType, username, password);

   }

}

您可以通过取消注释语句上设置调试emailSession.setDebug(true);

编译并运行

现在，我们班是准备好了，让我们编译上面的类。我已经保存了类CheckingMails.java目录： /home/manisha/JavaMailAPIExercise. 我们需要 javax.mail.jar andactivation.jar 在classpath中。执行下面的命令从命令提示符编译类（两个罐子被放置在 /home/manisha/ 目录下）：

javac -cp /home/manisha/activation.jar:/home/manisha/javax.mail.jar: CheckingMails.java

现在，这个类被编译，执行下面的命令来运行：

java -cp /home/manisha/activation.jar:/home/manisha/javax.mail.jar: CheckingMails

验证输出

你可以看到一个类似的消息，如下命令控制台上：

messages.length---3
---------------------------------
Email Number 1
Subject: Today is a nice day
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@45f676cb
---------------------------------
Email Number 2
Subject: hiiii....
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@37f12d4f
---------------------------------
Email Number 3
Subject: helloo
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@3ad5ba3a