Question

我正在尝试从我的Gmail帐户中阅读电子邮件。第一封电子邮件已成功读取，但对于第二封电子邮件，它会提供ArrayOutOfBounds异常。我的代码是

package sendemail;
import javax.mail.*;
import java.net.*;
import java.util.*;
import javax.swing.JOptionPane;
/**
 *
 * @author kunal
 */
public class Test {
    public static void main(String args[])
    {
        Properties props = new Properties();
        props.setProperty("mail.store.protocol", "imaps");
        try {
            Session session = Session.getInstance(props, null);
            Store store = session.getStore();
            store.connect("imap.gmail.com", "myaccount@gmail.com", "mypassword");
            Folder inbox = store.getFolder("INBOX");
            inbox.open(Folder.READ_ONLY);
            Message[] messages = inbox.getMessages(); 

   for (int i = 0; i <=messages.length; i++) {  
    Message message = messages[i];
    Multipart mp=(Multipart)message.getContent();
    BodyPart bp=mp.getBodyPart(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: " + bp.getContent());  
   }
        } catch (Exception mex) {
            mex.printStackTrace();
        }

    }
}

错误

Email Number 1
Subject: Three tips to get the most out of Gmail
From: Gmail Team <mail-noreply@google.com>
Text:  Three tips to get the most out of Gmail
[image: Google]

Hi Kunal

Tips to get the most out of Gmail

[image: Contacts]
Bring your contacts and mail into Gmail

On your computer, you can copy your contacts and emails from your old email
account to make the transition to Gmail even better. Learn
how<https://support.google.com/mail/answer/164640?hl=en&ref_topic=1669014>
.
[image: Search]
Find what you need fast

With the power of Google Search right in your inbox, it's easy to sort your
email. Find what you're looking for with predictions based on email
content, past searches and contacts.
[image: Search]
Much more than email

You can send text messages and make video calls with
Hangouts<https://www.google.com/intl/en/hangouts/>right from Gmail. To
use this feature on mobile, download the Hangouts app
for Android<https://play.google.com/store/apps/details?id=com.google.android.talk&hl=en>and
Apple <https://itunes.apple.com/en/app/hangouts/id643496868?mt=8> devices.


[image: Gmail icon]Happy emailing,
The Gmail Team
 © 2014 Google Inc. 1600 Amphitheatre Parkway, Mountain View, CA 94043

---------------------------------
Email Number 2
Subject: The best of Gmail, wherever you are
From: Gmail Team <mail-noreply@google.com>
Text: <!DOCTYPE html>
<html><head><meta http-equiv="content-type" content="text/html;charset=UTF-8" /><title>The best of Gmail, wherever you are</title></head><body style="background-color:#e5e5e5; margin:20px 0;"><br /><div style="margin:2%;"><div style="direction:ltr; text-align:left; font-family:'Open sans','Arial',sans-serif; color:#444; background-color:white; padding:1.5em; border-radius:1em; box-shadow:1px -5px 8px 2px #bbb; max-width:580px; margin:2% auto 0 auto;"><table style="background:white;width:100%"><tr><td><div style="width:90px; height:54px; margin:10px auto;"><img src="https://services.google.com/fh/files/emails/google_logo_flat_90_color.png" alt="Google" width="90" height="34"/></div><div style="float:right; padding-top:2em;"><img src="https://ssl.gstatic.com/accounts/services/mail/msa/welcome_nexus.png" alt="Nexus 4 with Gmail" style="border:0; margin-right:10px;" width="155" height="242"/></div><div style="width:90%; padding-bottom:10px; padding-left:15px"><p><img alt="" src="https://ssl.gstatic.com/accounts/services/mail/msa/gmail_icon_small.png" style="display:block; float:left; margin-top:4px; margin-right:5px;"/><span style="font-family:'Open sans','Arial',sans-serif; font-weight:bold; font-size:small; line-height:1.4em">Hi Kunal</span></p><p><span style="font-family:'Open sans','Arial',sans-serif; font-size:2.08em;"><br/>Get the official Gmail app</span><br/></p></div><p></p><div style="padding-left:15px"><p style="size:small; line-height:1.4em;">The best features of Gmail are only available on your phone and tablet with the official Gmail app. Download the app or go to <a href="https://www.gmail.com/" target="_blank" style="text-decoration:none; color:#15C">gmail.com</a> on your computer or mobile device to get started.</p><p style="line-height:2em; margin-right:170px;"><a href="https://play.google.com/store/apps/details?id=com.google.android.gm" style="text-decoration:none"><img alt="Google Play" width="127" height="44" src="https://ssl.gstatic.com/accounts/services/mail/buttons/google_play_en.png" style="border:0" /></a>&nbsp;&nbsp;<a href="https://itunes.apple.com/en/app/gmail/id422689480?mt=8" style="text-decoration:none;"><img alt="App Store" width="144" height="43" src="https://ssl.gstatic.com/accounts/services/mail/buttons/apple_store_en.png" style="border:0" /></a></p></div><br/><br/>
<div style="clear:both; padding-left:13px; height:6.8em;"><table style="width:100%; border-collapse:collapse; border:0"><tr><td style="width:68px"><img alt='Gmail icon' width="49" height="37" src="http://ssl.gstatic.com/accounts/services/mail/msa/gmail_icon_large.png" style="display:block;"/></td><td style="align:left; font-family:'Open sans','Arial',sans-serif; vertical-align:bottom"><span style="font-size:small">Happy emailing,<br/></span><span style="font-size:x-large; line-height:1">The Gmail Team</span></td></tr></table></div>
</td></tr></table></div>
<div style="direction:ltr;color:#777; font-size:0.8em; border-radius:1em; padding:1em; margin:0 auto 4% auto; font-family:'Arial','Helvetica',sans-serif; text-align:center;">© 2014 Google Inc. 1600 Amphitheatre Parkway, Mountain View, CA 94043<br/></div></div></body></html>

java.lang.ArrayIndexOutOfBoundsException: 2 >= 2
    at java.util.Vector.elementAt(Vector.java:470)
    at javax.mail.Multipart.getBodyPart(Multipart.java:156)
    at javax.mail.internet.MimeMultipart.getBodyPart(MimeMultipart.java:258)
    at sendemail.Test.main(Test.java:32)
BUILD SUCCESSFUL (total time: 10 seconds)

第一封电子邮件，即电子邮件号码1成功显示，但对于电子邮件号码2，它会给出例外情况。我的收件箱中共有3封邮件

Answer 1

实际导致异常的错误是：

BodyPart bp=mp.getBodyPart(i);

应该是：

BodyPart bp=mp.getBodyPart(0);

您应该将此部分放在for循环中，因为您可以拥有多个身体部位。查看documentation

解决此问题时的另一个错误是：

for (int i = 0; i <= messages.length; i++)

Java中的数组是基于零的，这意味着第一个元素的索引是0，最后一个元素的索引是array.length -1。你应该把它改成：

for (int i = 0; i < messages.length; i++)

使用javamail通过gmail读取电子邮件时出现ArrayOutOfBoundException

1 个答案: