以下代码应该从邮件中下载任何附件（如果有）。 Gmali、pop3、javax.mail ...任何IDE如何执行此操作，也许针对邮件的特定发件人，或者检查该邮件是否在标题中存在特定单词或类似内容？
package emailattachmentsdownloader;
import java.io.File;
import java.io.IOException;
import java.util.Properties;
import javax.mail.Address;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.NoSuchProviderException;
import javax.mail.Part;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.internet.MimeBodyPart;
/**
* This program demonstrates how to download e-mail messages and save
* attachments into files on disk.
*
*
*
*/
public class EmailAttachmentsDownloader {
private String saveDirectory;
/**
* Sets the directory where attached files will be stored.
* @param dir absolute path of the directory
*/
public void setSaveDirectory(String dir) {
this.saveDirectory = dir;
}
/**
* Downloads new messages and saves attachments to disk if any.
* @param host
* @param port
* @param userName
* @param password
*/
public void downloadEmailAttachments(String host, String port,
String userName, String password) {
Properties properties = new Properties();
// server setting
properties.put("mail.pop3.host", host);
properties.put("mail.pop3.port", port);
// SSL setting
properties.setProperty("mail.pop3.socketFactory.class",
"javax.net.ssl.SSLSocketFactory");
properties.setProperty("mail.pop3.socketFactory.fallback", "false");
properties.setProperty("mail.pop3.socketFactory.port",
String.valueOf(port));
Session session = Session.getDefaultInstance(properties);
try {
// connects to the message store
Store store = session.getStore("pop3");
store.connect(userName, password);
// opens the inbox folder
Folder folderInbox = store.getFolder("INBOX");
folderInbox.open(Folder.READ_ONLY);
// fetches new messages from server
Message[] arrayMessages = folderInbox.getMessages();
for (int i = 0; i < arrayMessages.length; i++) {
Message message = arrayMessages[i];
Address[] fromAddress = message.getFrom();
String from = fromAddress[0].toString();
String subject = message.getSubject();
String sentDate = message.getSentDate().toString();
String contentType = message.getContentType();
String messageContent = "";
// store attachment file name, separated by comma
String attachFiles = "";
if (contentType.contains("multipart")) {
// content may contain attachments
Multipart multiPart = (Multipart) message.getContent();
int numberOfParts = multiPart.getCount();
for (int partCount = 0; partCount < numberOfParts; partCount++) {
MimeBodyPart part = (MimeBodyPart) multiPart.getBodyPart(partCount);
if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition())) {
// this part is attachment
String fileName = part.getFileName();
attachFiles += fileName + ", ";
part.saveFile(saveDirectory + File.separator + fileName);
} else {
// this part may be the message content
messageContent = part.getContent().toString();
}
}
if (attachFiles.length() > 1) {
attachFiles = attachFiles.substring(0, attachFiles.length() - 2);
}
} else if (contentType.contains("text/plain")
|| contentType.contains("text/html")) {
Object content = message.getContent();
if (content != null) {
messageContent = content.toString();
}
}
// print out details of each message
System.out.println("Message #" + (i + 1) + ":");
System.out.println("\t From: " + from);
System.out.println("\t Subject: " + subject);
System.out.println("\t Sent Date: " + sentDate);
System.out.println("\t Message: " + messageContent);
System.out.println("\t Attachments: " + attachFiles);
}
// disconnect
folderInbox.close(false);
store.close();
} catch (NoSuchProviderException ex) {
System.out.println("No provider for pop3.");
ex.printStackTrace();
} catch (MessagingException ex) {
System.out.println("Could not connect to the message store");
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
}
/**
* Runs this program with Gmail POP3 server
*/
public static void main(String[] args) {
String host = "pop.gmail.com";
String port = "995";
String userName = "MYMAIL";
String password = "MYPASS";
String saveDirectory = "D:/Attachments";
EmailAttachmentsDownloader receiver = new
EmailAttachmentsDownloader();
receiver.setSaveDirectory(saveDirectory);
receiver.downloadEmailAttachments(host, port, userName, password);
}
}
但是当我运行它时，出现以下错误。有什么问题，我该怎么办？
Exception in thread "main" java.lang.NoClassDefFoundError:
com/sun/mail/util/MailLogger
at javax.mail.Session.initLogger(Session.java:227)
at javax.mail.Session.<init>(Session.java:212)
at javax.mail.Session.getDefaultInstance(Session.java:315)
at javax.mail.Session.getDefaultInstance(Session.java:355)
at emailattachmentsdownloader.EmailAttachmentsDownloader.downloadEmailAttachments(EmailAttachmentsDownloader.java:53)
at emailattachmentsdownloader.EmailAttachmentsDownloader.main(EmailAttachmentsDownloader.java:144)
Caused by: java.lang.ClassNotFoundException: com.sun.mail.util.MailLogger
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 6 more
C:\Users\Aca\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53:
Java returned: 1
BUILD FAILED (total time: 0 seconds)
在 pom.xml 中添加以下依赖项并尝试再次重建：
<dependencies>
<dependency>
<groupId>com.sun.mail</groupId>
<artifactId>javax.mail</artifactId>
<version>1.6.1</version>
</dependency>
</dependencies>
我在使用 Jakarta Mail API 时遇到问题。 附件的文件名 - 无论文件类型（.pdf、.tiff、.jpg） - 总是很奇怪，例如：
part.getFileName(): =?US-ASCII?B?Y3R5IFBhcmthdXN3ZWlzLnBkZg==?= part.getFileName() 与 MimeUtility: =?US-ASCII?B?Y3R5IFBhcmthdXN3ZWlzLnBkZg==?=
代码嵌入在下面。 我的系统：
IntelliJ IDEA 2022.2.4（终极版） 版本 #IU-222.4459.24，建于 2022 年 11 月 22 日 授权给公司/J.D. 您拥有此版本的永久后备许可证。 订阅有效期至 2024 年 12 月 31 日。 运行时版本：17.0.5+7-b469.71 amd64 VM：JetBrains s.r.o. 的 OpenJDK 64 位服务器 VM Windows 10 10.0 詹金斯插件 0.13.16-2022.2 GC：G1年轻代，G1老一代 内存：4096M 核心：16 注册表： debugger.watches.in.variables=false ide.tooltip.initialDelay=191
非捆绑插件： intellij 时钟 (2.0.0) com.mle.idea.sbtexecutor (1.4.1) com.markskelton.one-dark-theme (5.8.0) com.jetbrains.jax.ws (222.4459.16) com.genuitec.codetogether (2023.2.0-01430) 字符串操作 (9.6.1) 主要推动者 X (2022.2) Jira 浏览器 (0.3.3) Jenkins 控制插件 (0.13.16-2022.2) com.intellij.plugins.html.instantEditing (222.4459.16) com.atsebak.ui5 (2.05) Pythonid (222.4459.24) org.exbin.deltahex.intellij (0.2.7) MavenRunHelper (4.23.222.2964.0)
Kotlin：222-1.7.10-release-334-IJ4459.24
我的pom.xml：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>de.ourcompany</groupId>
<artifactId>pom.util</artifactId>
<version>2.0.1-SNAPSHOT</version>
</parent>
<artifactId>jakarta-mail</artifactId>
<version>2.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<dependencies>
<dependency>
<groupId>de.ourcompany</groupId>
<artifactId>util.config</artifactId>
<version>2.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>de.ourcompany</groupId>
<artifactId>util.cdi-transactionhandling</artifactId>
<version>2.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>de.cortility</groupId>
<artifactId>util.web</artifactId>
<version>2.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>jakarta.mail</groupId>
<artifactId>jakarta.mail-api</artifactId>
<version>2.1.2</version>
</dependency>
<dependency>
<groupId>com.sun.mail</groupId>
<artifactId>imap</artifactId>
<version>2.0.1</version>
</dependency>
<dependency>
<groupId>org.eclipse.angus</groupId>
<artifactId>angus-mail</artifactId>
<version>2.0.2</version>
<scope>runtime</scope>
</dependency>
<!-- expression language for dynamic bean validation -->
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>jakarta.el</artifactId>
</dependency>
<!-- hibernate bean validation cdi integration -->
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator-cdi</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator-annotation-processor</artifactId>
</dependency>
<dependency>
<groupId>org.jboss.weld.servlet</groupId>
<artifactId>weld-servlet-core</artifactId>
</dependency>
<!-- Dependencies for testing only -->
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>de.ourcompany</groupId>
<artifactId>util.cdi-testing</artifactId>
<version>2.0.1-SNAPSHOT</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>de.ourcompany</groupId>
<artifactId>component.dataexchange.mail</artifactId>
<version>2.0.0-SNAPSHOT</version>
</dependency>
</dependencies>
</project>public JakartaMailFetcher(final Config config, final String messageBoxSource) throws MessagingException, FileNotFoundException {
this.mailFetcherConfigTypes = config.getValueListAsString(JakartaMailFetcherMainConfig.MAIL_FETCHER_CONFIGURATIONS).toString();
this.host = config.getValueAsString(JakartaMailFetcherMainConfig.MAIL_FETCHER_HOST); // our company's host
this.port = config.getValueAsInteger(JakartaMailFetcherMainConfig.MAIL_FETCHER_PORT); // 143
this.user = config.getValueAsString(JakartaMailFetcherMainConfig.MAIL_FETCHER_USER);
if (config.getValueAsBoolean(JakartaMailFetcherMainConfig.MAIL_FETCHER_PASSWORD_AUTHENTICATION)) { // MAIL_FETCHER_PASSWORD_AUTHENTICATION = true
this.password = config.getValueAsString(JakartaMailFetcherMainConfig.MAIL_FETCHER_PASSWORD);
} else {
this.password = null;
}
System.out.printf("JakartaMailFetcher(final Config config) => config: %s\n", config);
System.out.printf("configurations available: %s\nhost: %s\nport: %s\npassword: ***\n", this.mailFetcherConfigTypes, this.host, this.port);
System.out.println("Now calling this.initMailFetcher(messageBoxSource) ...");
this.initMailFetcher(messageBoxSource);
this.fetchMails();
}
private void initMailFetcher(final String messageBoxSource) {
this.messageBoxName = messageBoxSource;
try {
this.initResultFileTxt();
this.systemProperties = this.getSystemProperties();
System.out.println("\necho >> this.mailSession = this.getMailSessionObject(this.systemProperties);");
this.mailSession = this.getMailSessionObject(this.systemProperties);
this.store = this.connectMailStore(this.mailSession);
} catch (Exception ex) {
System.out.println("Oops, got exception! " + ex.getMessage());
logger.error("Ooop an exception happened", ex);
}
}
private Properties getSystemProperties() {
// Get a Properties object
final Properties systemProperties = System.getProperties();
System.out.printf("%s %s %s %s %s", this.protocol, this.host, this.port, this.user, this.password);
if (this.protocol != null) {
systemProperties.put("mail.store.protocol", this.protocol);
}
systemProperties.put("mail." + this.protocol + ".host", this.host); // this.protocol = "imap";
systemProperties.put("mail." + this.protocol + ".port", this.port);
systemProperties.put("mail.user", this.user);
if (this.password != null) {
systemProperties.put("mail.password", this.password);
}
return systemProperties;
}
private Session getMailSessionObject(final Properties systemProperties) throws Exception {
System.out.println("Session getMailSessionObject(final Properties systemProperties)");
// Get a Session object
final Session mailSession = Session.getDefaultInstance(systemProperties, null);
mailSession.setDebug(debug);
return mailSession;
}
private Store connectMailStore(final Session mailSession) throws MessagingException {
Store store = null;
if (this.url != null) {
final URLName urlName = new URLName(this.url);
store = mailSession.getStore(urlName);
if (this.showAlert) {
store.addStoreListener(new StoreListener() {
@Override
public void notification(final StoreEvent storeEvent) {
final String storeEventMessageString;
if (storeEvent.getMessageType() == StoreEvent.ALERT) {
storeEventMessageString = "ALERT: ";
} else {
storeEventMessageString = "NOTICE: ";
}
System.out.println(storeEventMessageString + storeEvent.getMessage());
}
});
}
store.connect();
} else {
System.out.println("echo >> this.url == null");
if (this.protocol != null) {
store = mailSession.getStore(this.protocol);
} else {
store = mailSession.getStore();
}
// Connect
if (this.host != null
|| this.user != null
|| this.password != null) {
store.connect(this.host, this.port, this.user, this.password);
} else {
store.connect();
}
}
return store;
}
public void fetchMails() throws MessagingException {
try {
// Open the Folder
final Folder folder = getMailFolder(this.store);
this.openMailFolder(folder);
this.fetchMailsAndSaveAttachments(folder);
folder.close(false);
this.store.close();
} catch (final Exception e) {
throw new OurCompanysException(e);
}
}
private Folder getMailFolder(final Store store) throws Exception {
Folder defaultFolder = store.getDefaultFolder();
final Folder javaCiMailInbox = store.getFolder(JAVA_CI_INBOX);
final Folder[] defaultFolderSubFolders = store.getDefaultFolder().list();
for (Folder fd : defaultFolderSubFolders) {
System.out.println(">> " + fd.getName());
}
System.out.printf("JAVA CI INBOX >> %s\t %d messages", store.getFolder(JAVA_CI_INBOX).getName(), store.getFolder(JAVA_CI_INBOX).getMessageCount());
System.out.printf("\nCTY_VERARBEITET >> %s\t%s messages", store.getFolder(CTY_VERARBEITET).getName(), store.getFolder(CTY_VERARBEITET).getMessageCount());
System.out.printf("\nCTY_FEHLER >> %s\t%s messages", store.getFolder(CTY_FEHLER).getName(), store.getFolder(CTY_FEHLER).getMessageCount());
if (defaultFolder == null) {
System.out.println("No default defaultFolder");
}
if (this.messageBoxName == null) {
this.messageBoxName = "INBOX";
}
assert defaultFolder != null;
defaultFolder = defaultFolder.getFolder(this.messageBoxName);
if (defaultFolder == null) {
System.out.println("Invalid defaultFolder");
}
return javaCiMailInbox; // defaultFolder;
}
private void openMailFolder(final Folder givenFolder) throws MessagingException {
// try to open read/write and if that fails try read-only
try {
givenFolder.open(Folder.READ_WRITE);
} catch (final MessagingException messagingException) {
givenFolder.open(Folder.READ_ONLY);
}
final int totalMessages = givenFolder.getMessageCount();
if (totalMessages == 0) {
System.out.printf("Folder %s is an empty folder\n", givenFolder);
givenFolder.close(false);
givenFolder.close();
}
}
private void fetchMailsAndSaveAttachments(final Folder folder) throws Exception {
final Message[] folderMessages = folder.getMessages();
for (int counter = 0; counter < folderMessages.length; counter++) {
System.out.println("\nmessage " + counter + " content:\n" + folderMessages[counter].getContent().toString());
this.saveMessageAsEMLFile(folderMessages[counter], ""); // SAVE-AS-EML-FILE |--- JDU ---|
if (this.saveAttachments) {
this.saveMailAttachment((MimeMessage)folderMessages[counter], Arrays.asList(MimeType.PDF, MimeType.GIF, MimeType.JPEG, MimeType.TIFF));
}
}
this.myWriter.close();
}
private void saveMessageAsEMLFile(final Message msg, final String filename) throws MessagingException, IOException {
System.out.println("\nSaving message as .eml file and saving its attachment if available...");
try {
OutputStream out = null;
try {
final SimpleDateFormat dateFormat= new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); // new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
final String messageDate = dateFormat.format(msg.getSentDate());
System.out.println("mail sent date in milliseconds" + messageDate);
final String messageSubject = msg.getSubject();
final String messageSender = msg.getFrom()[0].toString();
final String whereToSave = this.test_root_path + sanitizeFilename(messageDate + "-" + messageSender) + ".eml";
out = new FileOutputStream(new File(whereToSave));
msg.writeTo(out);
} catch (final MessagingException messagingException) {
throw new OurCompanysException("Error while trying to save message file.", messagingException);
} finally {
if (out != null) {
out.flush();
out.close();
}
}
} catch (final IOException ioException) {
throw new OurCompanysException("Error while trying to save message file.", ioException);
}
}
private void saveMailAttachment(final MimeMessage givenMessage, final List<MimeType> mimeTypes) throws MessagingException, IOException, Exception {
System.out.println("Entry of saveMailAttachment");
System.out.println( givenMessage.getSubject() + " has contentType() -> " + givenMessage.getContentType());
if (givenMessage.getContentType().contains("multipart")) {
final Multipart multiPart = (Multipart) givenMessage.getContent();
final int numberOfBodyParts = multiPart.getCount();
System.out.println(givenMessage.getSubject() + " has " + numberOfBodyParts + " BodyParts");
for (int partCount = 0; partCount < numberOfBodyParts; partCount++) {
final BodyPart givenBodyPart = multiPart.getBodyPart(partCount);
final MimeBodyPart part = (MimeBodyPart) multiPart.getBodyPart(partCount);
final Object attachmentContent = part.getContent();
logger.trace("Found attachment: \"{}\"", part.getContentType());
for (final MimeType mimeType : mimeTypes) {
if (StringUtils.startsWithIgnoreCase(part.getContentType(), mimeType.getValue())) {
logger.debug("Found suitable attachment: " + mimeType);
logger.debug("content type: " + attachmentContent.getClass());
final Attachment attachment = new Attachment();
attachment.setFileName(part.getFileName());
System.out.println("part.getFileName(): " + part.getFileName());
System.out.println("part.getFileName() with MimeUtility: " + MimeUtility.encodeText(part.getFileName(), "UTF-8", "B"));
}
}
}
}
}