Question

我需要从Gmail检索未读邮件。我正在使用Java Mail API。默认情况下，此API会检索从最旧到最新的邮件。但我需要先检索最近的邮件。可能吗？提前谢谢。

Answer 1

这是一个例子。不要忘记在类路径中添加javax.mail。

import javax.mail.*;
import javax.mail.search.FlagTerm;
import java.util.*;

public class GmailFetch {

  public static void main( String[] args ) throws Exception {

    Session session = Session.getDefaultInstance(new Properties( ));
    Store store = session.getStore("imaps");
    store.connect("imap.googlemail.com", 993, "username@gmail.com", "password");
    Folder inbox = store.getFolder( "INBOX" );
    inbox.open( Folder.READ_ONLY );

    // Fetch unseen messages from inbox folder
    Message[] messages = inbox.search(
        new FlagTerm(new Flags(Flags.Flag.SEEN), false));

    // Sort messages from recent to oldest
    Arrays.sort( messages, ( m1, m2 ) -> {
      try {
        return m2.getSentDate().compareTo( m1.getSentDate() );
      } catch ( MessagingException e ) {
        throw new RuntimeException( e );
      }
    } );

    for ( Message message : messages ) {
      System.out.println( 
          "sendDate: " + message.getSentDate()
          + " subject:" + message.getSubject() );
    }
  }
}

Answer 2

JavaMail为您提供了一组Message对象。消息按接收顺序排列。如果要首先查看最近收到的消息，请按相反的顺序浏览阵列。如果您想先查看最近的已发送消息，则需要按照其他答案中的说明对数组进行排序。

Answer 3

确保使用IMAP协议，因为它支持标记。

对您的代码进行以下更改：

替换 inbox.open( Folder.READ_ONLY ); 通过 inbox.open( Folder.READ_WRITE );
然后在阅读完消息后，设置如下标志：
```
message.setFlag(Flags.Flag.SEEN, true);
```

完整示例：

    import javax.mail.*;
    import javax.mail.search.FlagTerm;
    import java.util.*;

    public class GmailFetch {

      public static void main( String[] args ) throws Exception {

        Session session = Session.getDefaultInstance(new Properties( ));
        Store store = session.getStore("imaps");
        store.connect("imap.googlemail.com", 993, "username@gmail.com", "password");
        Folder inbox = store.getFolder( "INBOX" );
        inbox.open( Folder.READ_WRITE );

        // Fetch unseen messages from inbox folder
        Message[] messages = inbox.search(
            new FlagTerm(new Flags(Flags.Flag.SEEN), false));

        // Sort messages from recent to oldest
        Arrays.sort( messages, ( m1, m2 ) -> {
          try {
            return m2.getSentDate().compareTo( m1.getSentDate() );
          } catch ( MessagingException e ) {
            throw new RuntimeException( e );
          }
        } );

        for ( Message message : messages ) {
          System.out.println( 
              "sendDate: " + message.getSentDate()
              + " subject:" + message.getSubject() );
              message.setFlag(Flags.Flag.SEEN, true);
        }
      }
    }

Answer 4

我认为这可能有助于访问已读/未读/最近的邮件根据需要更改变量。

// search for all "unseen" messages

Flags seen = new Flags(Flags.Flag.SEEN);// try changing this SEEN to RECENT 

// set it true or false for seen & unseen mail

FlagTerm unseenFlagTerm = new FlagTerm(seen, false)
Message messages[] = inbox.search(unseenFlagTerm);

JavaMail使用IMAP阅读最近未读的邮件

4 个答案: