在本章中,我们将了解如何使用JavaMail API删除电子邮件.删除消息涉及使用与消息关联的标志.不同的状态有不同的标志,一些是系统定义的,一些是用户定义的.预定义标志在内部类Flags.Flag中定义,如下所示:
Flags.Flag.ANSWERED
Flags.Flag.DELETED
Flags.Flag.DRAFT
Flags.Flag.FLAGGED
Flags.Flag.RECENT
Flags.Flag.SEEN
Flags.Flag.USER
POP协议仅支持删除邮件.
删除程序中遵循的基本步骤为:
在属性中获取具有POP和SMPT服务器详细信息的Session对象.我们需要POP详细信息来检索消息和SMPT详细信息以发送消息.
创建POP3商店对象并连接到商店.
创建文件夹对象并以READ_WRITE模式打开邮箱中的相应文件夹.
从收件箱文件夹中检索邮件.
如果要通过调用setFlag方法删除消息(Flags.Flag.DELETED,则迭代消息并输入"Y"或"y".在Message对象上.
标记为DELETED的消息实际上没有删除,直到我们调用Folder对象上的expunge()方法,或关闭将expunge设置为true的文件夹.
关闭商店对象.
创建Java类
创建一个java类文件 ForwardEmail ,其内容如下:
package com.it1352; import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.Properties;import javax.mail.Flags;import javax.mail.Folder;import javax.mail.Message;import javax.mail.MessagingException;import javax.mail.NoSuchProviderException;import javax.mail.Session;import javax.mail.Store;public class DeleteEmail { public static void delete(String pop3Host, String storeType, String user, String password) { try { // get the session object Properties properties = new Properties(); properties.put("mail.store.protocol", "pop3"); properties.put("mail.pop3s.host", pop3Host); properties.put("mail.pop3s.port", "995"); properties.put("mail.pop3.starttls.enable", "true"); Session emailSession = Session.getDefaultInstance(properties); // emailSession.setDebug(true); // create the POP3 store object and connect with the pop server Store store = emailSession.getStore("pop3s"); store.connect(pop3Host, user, password); // create the folder object and open it Folder emailFolder = store.getFolder("INBOX"); emailFolder.open(Folder.READ_WRITE); BufferedReader reader = new BufferedReader(new InputStreamReader( System.in)); // 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; i < messages.length; 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]); String subject = message.getSubject(); System.out.print("Do you want to delete this message [y/n] ? "); String ans = reader.readLine(); if ("Y".equals(ans) || "y".equals(ans)) { // set the DELETE flag to true message.setFlag(Flags.Flag.DELETED, true); System.out.println("Marked DELETE for message: " + subject); } else if ("n".equals(ans)) { break; } } // expunges the folder to remove messages which are marked deleted emailFolder.close(true); store.close(); } catch (NoSuchProviderException e) { e.printStackTrace(); } catch (MessagingException e) { e.printStackTrace(); } catch (IOException io) { io.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 delete(host, mailStoreType, username, password); }}
您可以通过取消注释语句 emailSession来设置调试开启.setDebug(true);
编译并运行
现在我们的类已准备就绪,让我们编译上面的类.我已将类DeleteEmail.java保存到目录:/home/manisha/JavaMailAPIExercise .我们需要类路径中的jar javax.mail.jar 和 activation.jar .执行以下命令从命令提示符编译类(两个jar放在/home/manisha/目录中):
javac -cp/home/manisha/activation.jar:/home/manisha/javax.mail.jar:DeleEmail.java
现在该类已编译,请执行以下命令运行:
java -cp/home/manisha/activation.jar:/home/manisha/javax.mail.jar:DeleEmail
验证输出
您应该在命令控制台上看到以下消息:
messages.length---1---------------------------------Email Number 1Subject: TestingFrom: ABCDo you want to delete this message [y/n] ? yMarked DELETE for message: Testing