Java获取当天接收的邮件
介绍
在日常开发中,经常需要对邮件进行处理,比如获取当天接收的邮件。本文将教会你如何使用Java来实现这个功能。
整体流程
下面是获取当天接收的邮件的整体流程:
flowchart TD
A[连接邮箱服务器] --> B[获取收件箱]
B --> C[过滤出当天的邮件]
C --> D[获取邮件内容]
D --> E[处理邮件内容]
E --> F[关闭连接]
具体步骤
- 连接邮箱服务器:首先,我们需要连接到邮箱服务器。这里以使用JavaMail库连接到IMAP服务器为例,可以使用以下代码:
Properties props = new Properties();
props.put("mail.store.protocol", "imap");
props.put("mail.imap.host", "imap.example.com");
props.put("mail.imap.port", "993");
props.put("mail.imap.ssl.enable", "true");
Session session = Session.getInstance(props);
Store store = session.getStore("imap");
store.connect("username", "password");
- 获取收件箱:连接成功后,我们需要打开收件箱来获取邮件。可以使用以下代码:
Folder inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
Message[] messages = inbox.getMessages();
- 过滤出当天的邮件:我们需要将收件箱中的邮件按照日期进行过滤,只保留当天的邮件。可以使用以下代码:
Date today = new Date();
Calendar cal = Calendar.getInstance();
cal.setTime(today);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
Date startOfDay = cal.getTime();
List<Message> todayMessages = new ArrayList<>();
for (Message message : messages) {
Date sentDate = message.getSentDate();
if (sentDate.after(startOfDay)) {
todayMessages.add(message);
}
}
- 获取邮件内容:我们可以遍历当天的邮件列表,获取每一封邮件的内容。可以使用以下代码:
for (Message message : todayMessages) {
String from = message.getFrom()[0].toString();
String subject = message.getSubject();
String content = getTextFromMessage(message);
// 处理邮件内容...
}
-
处理邮件内容:在这一步,我们可以根据具体需求对邮件内容进行处理,比如打印邮件的发件人、主题和内容等。根据具体需求编写代码即可。
-
关闭连接:最后,我们需要关闭与邮箱服务器的连接。可以使用以下代码:
inbox.close(false);
store.close();
完整代码示例
import javax.mail.*;
import javax.mail.internet.MimeMultipart;
import java.util.*;
public class EmailReader {
public static void main(String[] args) {
Properties props = new Properties();
props.put("mail.store.protocol", "imap");
props.put("mail.imap.host", "imap.example.com");
props.put("mail.imap.port", "993");
props.put("mail.imap.ssl.enable", "true");
Session session = Session.getInstance(props);
Store store = null;
try {
store = session.getStore("imap");
store.connect("username", "password");
Folder inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
Message[] messages = inbox.getMessages();
Date today = new Date();
Calendar cal = Calendar.getInstance();
cal.setTime(today);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
Date startOfDay = cal.getTime();
List<Message> todayMessages = new ArrayList<>();
for (Message message : messages) {
Date sentDate = message.getSentDate();
if (sentDate.after(startOfDay)) {
todayMessages.add(message);
}
}
for (Message message : todayMessages) {
String from = message.getFrom()[0].toString();
String subject = message.getSubject();
String content = getTextFromMessage(message);
System.out.println("From: " + from);
System.out.println("Subject: " + subject);
System.out.println("Content: " + content);
System.out.println("------------------------");
}
inbox.close(false);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (store != null) {
try {
store.close();
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
}
private static String getTextFromMessage(Message message) throws Exception {
if (message.isMimeType