添加依赖

org.springframework.boot

spring-boot-starter-mail

获取邮件附件代码

package com.example.emaildemo.email;

import javax.mail.*;

import javax.mail.internet.InternetAddress;

import javax.mail.internet.MimeUtility;

import javax.mail.search.*;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.time.LocalDateTime;

import java.time.ZoneId;

import java.time.ZonedDateTime;

import java.util.*;

public class Pop3Mails {

public static void main(String[] args) {

Pop3Mails mail = new Pop3Mails();

mail.read();

}

public void read() {

Properties props = new Properties();

try {

final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";

props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);

props.setProperty("mail.pop3.socketFactory.fallback", "false");

props.setProperty("mail.pop3.port", "995");

props.setProperty("mail.pop3.socketFactory.port", "995");

Session session = Session.getDefaultInstance(props, null);

Store store = session.getStore("pop3");

String user = "xxxx@gmail.com";

// 如果为gmail需开通二次验证密码

String password = "xxxxxx";

store.connect("pop.gmail.com", user, password);

Folder inbox = store.getFolder("inbox");

inbox.open(Folder.READ_ONLY);

LocalDateTime localDateTime = LocalDateTime.now().minusYears(1);

ZoneId zoneId = ZoneId.systemDefault();

ZonedDateTime zdt = localDateTime.atZone(zoneId);//Combines this date-time with a time-zone to create a ZonedDateTime.

Date start = Date.from(zdt.toInstant());

Date now = new Date();

SearchTerm comparisonTermGe = new SentDateTerm(ComparisonTerm.GE, start);

SearchTerm comparisonTermLe = new SentDateTerm(ComparisonTerm.LE, now);

//需要查询的邮件名

String fromEmail = "xxxxxxxxxx@gmail.com";

FromStringTerm fromStringTerm = new FromStringTerm(fromEmail);

SearchTerm andTerm = new AndTerm(new SearchTerm[]{comparisonTermGe, comparisonTermLe});

Message[] messages = inbox.search(andTerm); //根据设置好的条件获取message

Message[] search = inbox.search(fromStringTerm, messages);

for (int i = search.length - 1; i >= 0; i--) {

Message message = search[i];

Date date = message.getSentDate();

System.out.println("Mail Subject:- " + message.getSubject());

System.out.println("Mail Content Type:- " + message.getContentType());

System.out.println("Mail Sent Date:- " + date);

if (message.getContentType().startsWith("multipart/")) {

needProcessEmail(message);

}

}

inbox.close(true);

store.close();

} catch (Exception e) {

e.printStackTrace();

}

}

/**

* 文件拷贝，在用户进行附件下载的时候，可以把附件的InputStream传给用户进行下载

*

* @param is

* @param os

* @throws IOException

*/

public static void copy(InputStream is, OutputStream os) throws IOException {

byte[] bytes = new byte[1024];

int len = 0;

while ((len = is.read(bytes)) != -1) {

os.write(bytes, 0, len);

}

if (os != null)

os.close();

if (is != null)

is.close();

}

private boolean needProcessEmail(Message msg) throws Exception {

System.out.println("needProcessEmail > 当前邮件的标题" + msg.getSubject());

// 1. 检查发件人邮箱是否包含在我们监控的邮箱列表里面

String from = getFrom(msg);

if (!isContainAttach((Part) msg)) {

System.out.println("发件人满足要求但是附件为空，不满足我们监控的需求！");

return false;

}

Map fileMap = new HashMap<>();

getFileInputStream(msg, fileMap);

if (fileMap.isEmpty()) {

System.out.println("尽管邮件中有附件但是邮件中的附件却无一个满足要求！");

return false;

}

System.out.println(fileMap);

for (String s : fileMap.keySet()) {

InputStream inputStream = fileMap.get(s);

copy(inputStream, new FileOutputStream("D:\\" + s));

}

return true;

}

private String getFrom(Message msg) throws MessagingException {

String from = "";

InternetAddress[] addresses = (InternetAddress[]) msg.getFrom();

if (null == addresses || addresses.length == 0) {

System.out.println("无法获取发送人地址信息");

return from;

}

Address address = addresses[0];

System.out.println("件人地址json：" + address);

String form = ((InternetAddress) address).getAddress();

return form;

}

private void getFileInputStream(Part part, Map inputStreamMap) throws Exception {

String fileName;

if (part.isMimeType("multipart/*")) {

Multipart mp = (Multipart) part.getContent();

for (int i = 0; i < mp.getCount(); i++) {

BodyPart mPart = mp.getBodyPart(i);

String disposition = mPart.getDisposition();

if ((disposition != null)

&& ((disposition.equals(Part.ATTACHMENT)) || (disposition

.equals(Part.INLINE)))) {

fileName = mPart.getFileName();

if (fileName.toLowerCase().contains("gb2312")) {

fileName = MimeUtility.decodeText(fileName);

}

if (checkFileName(fileName)) {

inputStreamMap.put(fileName, mPart.getInputStream());

}

} else if (mPart.isMimeType("multipart/*")) {

System.out.println("子邮件里面的附件");

getFileInputStream(mPart, inputStreamMap);

} else {

fileName = mPart.getFileName();

if ((fileName != null)

&& (fileName.toLowerCase().contains("GB2312"))) {

fileName = MimeUtility.decodeText(fileName);

if (checkFileName(fileName)) {

inputStreamMap.put(fileName, mPart.getInputStream());

}

}

}

}

} else if (part.isMimeType("message/rfc822")) {

getFileInputStream((Part) part.getContent(), inputStreamMap);

}

}

private boolean checkFileName(String fileName) {

return true;

}

private boolean isContainAttach(Part part) throws Exception {

boolean attachFlag = false;

// String contentType = part.getContentType();

if (part.isMimeType("multipart/*")) {

Multipart mp = (Multipart) part.getContent();

for (int i = 0; i < mp.getCount(); i++) {

BodyPart mPart = mp.getBodyPart(i);

String disposition = mPart.getDisposition();

if ((disposition != null)

&& ((disposition.equals(Part.ATTACHMENT)) || (disposition

.equals(Part.INLINE)))) {

attachFlag = true;

} else if (mPart.isMimeType("multipart/*")) {

attachFlag = isContainAttach((Part) mPart);

} else {

String conType = mPart.getContentType();

if (conType.toLowerCase().contains("application")) {

attachFlag = true;

}

if (conType.toLowerCase().contains("name")) {

attachFlag = true;

}

}

}

} else if (part.isMimeType("message/rfc822")) {

attachFlag = isContainAttach((Part) part.getContent());

}

return attachFlag;

}

}