使用javaMail收邮件支持附件下载

javaMail 发送复杂邮件附件

使用javaMail收邮件主要有两种协议，一种是pop3，一种是imap。这两种协议都可以用来收邮件，但是在其中的处理上是有区别的。pop3是不支持判断邮件是否为已读的，也就是说你不能直接从收件箱里面取到未读邮件，这需要自己进行判断，然而imap就提供了这样的功能，使用imap时可以很轻松的判断该邮件是否为已读或未读或其他。

此外收件箱中的每一封邮件都对应着一个MessageNumber，所以可以通过一个MessageNumber拿到对应的那封邮件。如：Message message = folder.getMessage(messageNumber);

pop3和imap主要区别就是能否判断邮件状态的问题，其他的操作都差不多.

pop3收邮件和解析邮件：

Java代码

package com.clxx.test;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;
import javax.mail.BodyPart;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.internet.MimeMultipart;
public class Email2 {
public static void main(String args[]) throws MessagingException,
IOException {
Properties props = new Properties();
props.setProperty("mail.store.protocol", "pop3");
props.setProperty("mail.pop3.host", "pop3.sohu.com");
Session session = Session.getDefaultInstance(props);
Store store = session.getStore("pop3");
store.connect("username@sohu.com", "password");
Folder folder = store.getFolder("INBOX");
folder.open(Folder.READ_WRITE);
// 全部邮件数
int messageCount = folder.getMessageCount();
System.out.println(messageCount);
Message[] messages = folder.getMessages();
for (int i = 0; i < messages.length; i++) {
Message message = messages[i];
System.out.println(message.getSubject());
// 删除邮件
// message.setFlag(Flags.Flag.DELETED, true);
// 标记为已读
// message.setFlag(Flags.Flag.SEEN, true);
//pop3没有判断邮件是否为已读的功能，要使用Imap才可以
/*Flags flags = message.getFlags();
if (flags.contains(Flags.Flag.SEEN))
System.out.println("这是一封已读邮件");
else {
System.out.println("未读邮件");
message.setFlag(Flags.Flag.SEEN, true);
}*/
System.out.println("发送时间：" + message.getSentDate());
System.out.println("主题：" + message.getSubject());
System.out.println("内容：" + message.getContent());
//获取所有的Header，头信息
Enumeration headers = message.getAllHeaders();
System.out.println("----------------------allHeaders-----------------------------");
/* while (headers.hasMoreElements()) {
Header header = (Header)headers.nextElement();
System.out.println(header.getName()+" ======= "+header.getValue());
}*/
//解析邮件内容
Object content = message.getContent();
if (content instanceof MimeMultipart) {
MimeMultipart multipart = (MimeMultipart) content;
parseMultipart(multipart);
}
System.out
.println("========================================================");
System.out
.println("========================================================");
}
folder.close(true);
store.close();
}
/**
* 对复杂邮件的解析
* @param multipart
* @throws MessagingException
* @throws IOException
*/
public static void parseMultipart(Multipart multipart) throws MessagingException, IOException {
int count = multipart.getCount();
System.out.println("couont = "+count);
for (int idx=0;idx<count;idx++) {
BodyPart bodyPart = multipart.getBodyPart(idx);
System.out.println(bodyPart.getContentType());
if (bodyPart.isMimeType("text/plain")) {
System.out.println("plain................."+bodyPart.getContent());
} else if(bodyPart.isMimeType("text/html")) {
System.out.println("html..................."+bodyPart.getContent());
} else if(bodyPart.isMimeType("multipart/*")) {
Multipart mpart = (Multipart)bodyPart.getContent();
parseMultipart(mpart);
} else if (bodyPart.isMimeType("application/octet-stream")) {
String disposition = bodyPart.getDisposition();
System.out.println(disposition);
if (disposition.equalsIgnoreCase(BodyPart.ATTACHMENT)) {
String fileName = bodyPart.getFileName();
InputStream is = bodyPart.getInputStream();
copy(is, new FileOutputStream("D:\\"+fileName));
}
}
}
}
/**
* 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();
}
}

package com.clxx.test;import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;import javax.mail.BodyPart;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.internet.MimeMultipart;public class Email2 {public static void main(String args[]) throws MessagingException,IOException {Properties props = new Properties();props.setProperty("mail.store.protocol", "pop3");props.setProperty("mail.pop3.host", "pop3.sohu.com");Session session = Session.getDefaultInstance(props);Store store = session.getStore("pop3");store.connect("username@sohu.com", "password");Folder folder = store.getFolder("INBOX");folder.open(Folder.READ_WRITE);// 全部邮件数int messageCount = folder.getMessageCount();System.out.println(messageCount);Message[] messages = folder.getMessages();for (int i = 0; i < messages.length; i++) {Message message = messages[i];System.out.println(message.getSubject());// 删除邮件// message.setFlag(Flags.Flag.DELETED, true);// 标记为已读// message.setFlag(Flags.Flag.SEEN, true);//pop3没有判断邮件是否为已读的功能，要使用Imap才可以/*Flags flags = message.getFlags();if (flags.contains(Flags.Flag.SEEN))System.out.println("这是一封已读邮件");else {System.out.println("未读邮件");message.setFlag(Flags.Flag.SEEN, true);}*/System.out.println("发送时间：" + message.getSentDate());System.out.println("主题：" + message.getSubject());System.out.println("内容：" + message.getContent());//获取所有的Header，头信息Enumeration headers = message.getAllHeaders();System.out.println("----------------------allHeaders-----------------------------");/*	while (headers.hasMoreElements()) {Header header = (Header)headers.nextElement();System.out.println(header.getName()+" ======= "+header.getValue());}*///解析邮件内容Object content = message.getContent();if (content instanceof MimeMultipart) {MimeMultipart multipart = (MimeMultipart) content;parseMultipart(multipart);}System.out.println("========================================================");System.out.println("========================================================");}folder.close(true);store.close();}/*** 对复杂邮件的解析* @param multipart* @throws MessagingException* @throws IOException*/public static void parseMultipart(Multipart multipart) throws MessagingException, IOException {int count = multipart.getCount();System.out.println("couont =  "+count);for (int idx=0;idx<count;idx++) {BodyPart bodyPart = multipart.getBodyPart(idx);System.out.println(bodyPart.getContentType());if (bodyPart.isMimeType("text/plain")) {System.out.println("plain................."+bodyPart.getContent());} else if(bodyPart.isMimeType("text/html")) {System.out.println("html..................."+bodyPart.getContent());} else if(bodyPart.isMimeType("multipart/*")) {Multipart mpart = (Multipart)bodyPart.getContent();parseMultipart(mpart);} else if (bodyPart.isMimeType("application/octet-stream")) {String disposition = bodyPart.getDisposition();System.out.println(disposition);if (disposition.equalsIgnoreCase(BodyPart.ATTACHMENT)) {String fileName = bodyPart.getFileName();InputStream is = bodyPart.getInputStream();copy(is, new FileOutputStream("D:\\"+fileName));}}}}/*** 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();}}

使用imap协议接收邮件：

Java代码