为啥不用pop3而用imap，是因为imap能把邮件设置为已读，而pop3不能；
使用javamail mail.imap读取邮箱的邮件，综合网上的例子，贴出自己实际使用的代码供大家参考：
步骤： 1、设置被读取邮箱的安全性，允许我们的系统读取邮件，例如：网易邮箱，当读取邮件的时候，网易的邮箱会受到一封标题为“网易邮箱提醒：阻止了一次不安全的收信请求“的邮件
，
第二部：读取邮件和附件，每次读取未读的邮件，读完后，把邮件设为未读，我的这个需求不会考虑人工登录邮箱，读取邮件的情况，如果需要考虑，请略作修改
package com.ch.service.imp;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.Date;
import java.util.Properties;
import javax.annotation.Resource;
import javax.mail.Address;
import javax.mail.BodyPart;
import javax.mail.Flags;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Part;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;
import org.springframework.stereotype.Service;
import com.ch.dao.DocInfoMapper;
import com.ch.dao.EmailInfoMapper;
import com.ch.entity.DocInfo;
import com.ch.entity.EmailInfo;
import com.ch.service.MailInfoService;
import com.ch.util.Constant;
import com.ch.util.RmdeskConfig;
import com.ch.util.TypeCastUtil;
import com.sun.mail.imap.IMAPFolder;
import com.sun.mail.imap.IMAPStore;
@Service("mailInfoService")
public class MailInfoServiceImpl implements MailInfoService{
@Resource
private DocInfoMapper infoMapper;
@Resource
private EmailInfoMapper emailInfoMapper;
@Override
public void readMail(){
try {
Properties prop = System.getProperties();
prop.put("mail.store.protocol", RmdeskConfig.mailstoreprotocol);
prop.put("mail.imap.host", RmdeskConfig.mailimaphost);
Session session = Session.getInstance(prop);
IMAPStore store = (IMAPStore) session.getStore(RmdeskConfig.mailstoreprotocol); // 使用imap会话机制，连接服务器
store.connect(RmdeskConfig.euser, RmdeskConfig.epassword);
IMAPFolder folder = (IMAPFolder) store.getFolder("INBOX"); // 收件箱
folder.open(Folder.READ_WRITE);
//获取未读邮件
Message[] messages = folder.getMessages(folder.getMessageCount()-folder.getUnreadMessageCount()+1,folder.getMessageCount());
parseMessage(messages); //解析邮件
//释放资源
if (folder != null) folder.close(true);
if (store != null) store.close();
System.out.println("读取成功。。。。。。。。。。。。");
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
/**
* 解析邮件
* @param messages 要解析的邮件列表
*/
private void parseMessage(Message ...messages) throws MessagingException, IOException {
if (messages == null || messages.length < 1)
throw new MessagingException("未找到要解析的邮件!");
// 解析所有邮件
for (int i = 0, count = messages.length; i < count; i++) {
MimeMessage msg = (MimeMessage) messages[i];
msg.setFlag(Flags.Flag.SEEN, true);
//存储邮件信息
EmailInfo emaininfo = new EmailInfo();
emaininfo.setEmailcode(msg.getMessageID()); //ID
InternetAddress address = getFrom(msg);
emaininfo.setSender(address.getPersonal()+"<" + address.getAddress() + ">");//张三<zhangsan@163.com>
emaininfo.setTitle(decodeText(msg.getSubject()));//转码后的标题
emaininfo.setReceiver(getReceiveAddress(msg, null));//收件人
emaininfo.setAccepttime(msg.getSentDate());//收件日期
emaininfo.setCheckstatus(Constant.CHECK_STATUS_NO);
try {
emailInfoMapper.insert(emaininfo);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
System.out.println("----邮件信息存入数据库失败了。。。。。");
}
if (isContainAttachment(msg)) {//保存附件
saveAttachment(msg, RmdeskConfig.filepath,address.getAddress(),address.getPersonal());
}
}
}
/**
* 获得邮件发件人
* @param msg 邮件内容
* @return 地址
* @throws MessagingException
* @throws UnsupportedEncodingException
*/
private InternetAddress getFrom(MimeMessage msg) throws MessagingException, UnsupportedEncodingException {
Address[] froms = msg.getFrom();
if (froms.length < 1)
throw new MessagingException("没有发件人!");
return (InternetAddress) froms[0];
}
/**
* 根据收件人类型，获取邮件收件人、抄送和密送地址。如果收件人类型为空，则获得所有的收件人
* <p>Message.RecipientType.TO 收件人</p>
* <p>Message.RecipientType.CC 抄送</p>
* <p>Message.RecipientType.BCC 密送</p>
* @param msg 邮件内容
* @param type 收件人类型
* @return 收件人1 <邮件地址1>, 收件人2 <邮件地址2>, ...
* @throws MessagingException
*/
private String getReceiveAddress(MimeMessage msg, Message.RecipientType type) throws MessagingException {
StringBuffer receiveAddress = new StringBuffer();
Address[] addresss = null;
if (type == null) {
addresss = msg.getAllRecipients();
} else {
addresss = msg.getRecipients(type);
}
if (addresss == null || addresss.length < 1)
throw new MessagingException("没有收件人!");
for (Address address : addresss) {
InternetAddress internetAddress = (InternetAddress)address;
receiveAddress.append(internetAddress.toUnicodeString()).append(",");
}
receiveAddress.deleteCharAt(receiveAddress.length()-1); //删除最后一个逗号
return receiveAddress.toString();
}
/**
* 判断邮件中是否包含附件
* @param msg 邮件内容
* @return 邮件中存在附件返回true，不存在返回false
* @throws MessagingException
* @throws IOException
*/
private boolean isContainAttachment(Part part) throws MessagingException, IOException {
boolean flag = false;
if (part.isMimeType("multipart/*")) {
MimeMultipart multipart = (MimeMultipart) part.getContent();
int partCount = multipart.getCount();
for (int i = 0; i < partCount; i++) {
BodyPart bodyPart = multipart.getBodyPart(i);
String disp = bodyPart.getDisposition();
if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
flag = true;
} else if (bodyPart.isMimeType("multipart/*")) {
flag = isContainAttachment(bodyPart);
} else {
String contentType = bodyPart.getContentType();
if (contentType.indexOf("application") != -1) {
flag = true;
}
if (contentType.indexOf("name") != -1) {
flag = true;
}
}
if (flag) break;
}
} else if (part.isMimeType("message/rfc822")) {
flag = isContainAttachment((Part)part.getContent());
}
return flag;
}
/**
* 保存附件
* @param part 邮件中多个组合体中的其中一个组合体
* @param destDir 附件保存目录
* @throws UnsupportedEncodingException
* @throws MessagingException
* @throws FileNotFoundException
* @throws IOException
*/
private void saveAttachment(Part part, String destDir,String email,String sendName) throws UnsupportedEncodingException, MessagingException,
FileNotFoundException, IOException {
if (part.isMimeType("multipart/*")) {
Multipart multipart = (Multipart) part.getContent(); //复杂体邮件
//复杂体邮件包含多个邮件体
int partCount = multipart.getCount();
for (int i = 0; i < partCount; i++) {
//获得复杂体邮件中其中一个邮件体
BodyPart bodyPart = multipart.getBodyPart(i);
//某一个邮件体也有可能是由多个邮件体组成的复杂体
String disp = bodyPart.getDisposition();
if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
InputStream is = bodyPart.getInputStream();
this.saveFile(is, destDir, decodeText(bodyPart.getFileName()),email,sendName);
} else if (bodyPart.isMimeType("multipart/*")) {
saveAttachment(bodyPart,destDir,email,sendName);
} else {
String contentType = bodyPart.getContentType();
if (contentType.indexOf("name") != -1 || contentType.indexOf("application") != -1) {
this.saveFile(bodyPart.getInputStream(), destDir, decodeText(bodyPart.getFileName()),email,sendName);
}
}
}
} else if (part.isMimeType("message/rfc822")) {
saveAttachment((Part) part.getContent(),destDir,email,sendName);
}
}
/**
* 读取输入流中的数据保存至指定目录
* @param is 输入流
* @param fileName 文件名
* @param destDir 文件存储目录
* @throws FileNotFoundException
* @throws IOException
*/
private void saveFile(InputStream is, String destDir, String fileName,String email,String sendName)
throws FileNotFoundException, IOException {
//附件格式过滤
if(!TypeCastUtil.equals(RmdeskConfig.extname, TypeCastUtil.getFileDot(fileName))){
return;
}
DocInfo doc = new DocInfo();
doc.setDocName(fileName);
String uuidFilename = TypeCastUtil.getUUIDFileName(fileName);
doc.setUrl(uuidFilename);
doc.setBusinessLine("测试");
doc.setReceivedMode(Constant.OWNER_TYPE_EMAIL);
doc.setReceivedTime(new Date());
doc.setOwnerEmail(email);
doc.setOwnerName(sendName);
//TODO:入库
try {
infoMapper.insert(doc);
} catch (Exception e) {
e.printStackTrace();
System.out.println("----附件存入数据库失败了。。。。。");
}
BufferedInputStream bis = new BufferedInputStream(is);
BufferedOutputStream bos = new BufferedOutputStream(
new FileOutputStream(new File(destDir + uuidFilename)));
int len = -1;
while ((len = bis.read()) != -1) {
bos.write(len);
bos.flush();
}
bos.close();
bis.close();
}
/**
* 文本解码
* @param encodeText 解码MimeUtility.encodeText(String text)方法编码后的文本
* @return 解码后的文本
* @throws UnsupportedEncodingException
*/
private String decodeText(String encodeText) throws UnsupportedEncodingException {
if (encodeText == null || "".equals(encodeText)) {
return "";
} else {
return MimeUtility.decodeText(encodeText);
}
}
}
3、定时器以及项目启动时启动定时器
package com.ch.util;
import java.util.Timer;
import java.util.TimerTask;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import com.ch.service.MailInfoService;
public class RmdeskServletContextListener implements ServletContextListener {
@Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("-------------进入---ServletContextEvent----------------");
Timer timer = new Timer();
//ApplicationContext context = new ClassPathXmlApplicationContext("classpath:resources/conf/application-*.xml");
final MailInfoService service = SpringContextUtil.getBean("mailInfoService");//(MailInfoService)context.getBean("mailInfoService");
timer.schedule(new TimerTask() {
@Override
public void run() {
// TODO Auto-generated method stub
service.readMail();
}
}, 1000,1000*60*60*24);//1000*60*60*24
}
@Override
public void contextDestroyed(ServletContextEvent args) {
// TODO Auto-generated method stub
}
}
web.xml
<listener>
<listener-class>com.ch.util.RmdeskServletContextListener</listener-class>
</listener>
IMAPMessage imapMessage =(IMAPMessage)message; MimeMessage cmsg = new MimeMessage((MimeMessage) imapMessage);
System.out.println("内容：" + cmsg.getContent());
另：摘抄网上的读取文件内容，我自己的项目中用不到，供大家参考
/**
* 获得邮件文本内容
* @param part 邮件体
* @param content 存储邮件文本内容的字符串
* @throws MessagingException
* @throws IOException
*/
public static void getMailTextContent(Part part, StringBuffer content) throws MessagingException, IOException {
//如果是文本类型的附件，通过getContent方法可以取到文本内容，但这不是我们需要的结果，所以在这里要做判断
boolean isContainTextAttach = part.getContentType().indexOf("name") > 0;
if (part.isMimeType("text/*") && !isContainTextAttach) {
content.append(part.getContent().toString());
} else if (part.isMimeType("message/rfc822")) {
getMailTextContent((Part)part.getContent(),content);
} else if (part.isMimeType("multipart/*")) {
Multipart multipart = (Multipart) part.getContent();
int partCount = multipart.getCount();
for (int i = 0; i < partCount; i++) {
BodyPart bodyPart = multipart.getBodyPart(i);
getMailTextContent(bodyPart,content);
}
}
}
暂时就到这里了，有疑问欢迎大家随时沟通！