JavaMail接收邮件

代码不少,写了半天,又是查API的.

效果图:

package org.credo.javamail;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;
import java.util.UUID;

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.Store;
import javax.mail.URLName;
import javax.mail.internet.MimeUtility;

public class ReceiveMail {

	public static void main(String[] args) {
		ReceiveMail rmail=new ReceiveMail("账户", "密码", "pop.qq.com", 110);
		try {
			rmail.getMessage();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	private String account;
	private String password;
	private String pop3Host;
	private int pop3Port;
	
	private Store store;
	
	private ReceiveMail(String account,String password,String pop3Host,int pop3Port){
		this.account=account;
		this.password=password;
		this.pop3Host=pop3Host;
		this.pop3Port=pop3Port;
	}
	
	/**
	 * 获取信息体(数组),并打印出其具体信息.
	 */
	public void getMessage() throws Exception{
		//获取收件箱
		try {
			//INBOX 来表示“此服务器上此用户的主文件夹”。
			Folder inbox=getStore().getFolder("INBOX");
			///READ_WRITE 此文件夹的状态和内容可以修改。
			inbox.open(Folder.READ_WRITE);
			//得到INBOX里的所有信息,messages是所有信息个数组集合
			Message[] messages=inbox.getMessages();
			for(int i=0;i<messages.length;i++){
				System.out.println("----第"+(i+1)+"封邮件的信息---");
				printMessage(messages[i]);
			}
		} catch (MessagingException e) {
			e.printStackTrace();
		}
	}
	
	private void printMessage(Message message) throws Exception {
		System.out.println("");
		//打印出类似于com.sun.mail.pop3.POP3Message@428527的信息
		System.out.println(message.toString());
		System.out.println("接收日期:"+getReceivedDate(message));
		System.out.println("抄送地址:"+getCC(message));
		System.out.println("是否已读:"+hasRead(message));
		System.out.println("所有收件人:"+getAllRecipients(message));
		System.out.println("发件人地址:"+getSender(message));
		System.out.println("===邮件正文===\n"+getContent(message));
		for(String str:getFiles(message)){
			System.out.println("附件信息:"+str);
		}
	}
	
	/**
	 * @return 获取邮箱的存储对象
	 */
	public Store getStore(){
		if(this.store==null||!this.store.isConnected()){
			try {
				Properties props=new Properties();
				//创建mail的session
				Session session=Session.getDefaultInstance(props);
				//使用POP3协议接收邮件
				//根据指定协议、主机、端口号、文件(为空)、用户名和密码创建 URLName 对象.
				URLName url=new URLName("pop3",getPop3Host(),getPop3Port(),null,getAccount(),getPassword());
				//得到邮箱的存储对象
				Store store=session.getStore(url);
				store.connect();
				this.store=store;
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return this.store;
	}
	
	
	/**
	 * @return 获取接收日期.先获取发送日期,如果为空就获取接收日期,还没就当前日期.
	 */
	public Date getReceivedDate(Message m) throws MessagingException{
		if(m.getSentDate()!=null){
			return m.getSentDate();
		}
		if(m.getReceivedDate()!=null){
			return m.getReceivedDate();
		}
		return new Date();
	}
	
	/**
	 * @return 获取抄送人
	 */
	public List<String> getCC(Message m) throws MessagingException{
		Address[] addresses=m.getRecipients(Message.RecipientType.CC);
		return getAddresses(addresses);
	}
	
	/**
	 * @return 获取附件名称
	 */
	public List<String> getFiles(Message m) throws MessagingException, IOException{
		List<String> files=new ArrayList<String>();
		if(m.isMimeType("multipart/mixed")){
			Multipart mp=(Multipart) m.getContent();
			//得到邮件内容的Multipart对象并得到内容中的part的数量
			int count=mp.getCount();
			for(int i=1;i<count;i++){
				//获取附件
				Part part=mp.getBodyPart(i);
				//获取邮件附件名
				String serverFileName=MimeUtility.decodeText(part.getFileName());
				//生成UUID作为在本地系统中唯一的文件标识
//				String fileName=UUID.randomUUID().toString();
//				File file=new File(fileName+getFileSuffix(fileName));
//				//读写文件
//				FileOutputStream fos=new FileOutputStream(file);
//				InputStream is=part.getInputStream();
//				BufferedOutputStream outs=new BufferedOutputStream(fos);
//				//使用IO流读取邮件附件
//				byte[] b=new byte[1024];
//				int hasRead=0;
//				while((hasRead=is.read(b))>0){
//					outs.write(b,0,hasRead);
//				}
//				outs.close();
//				is.close();
//				fos.close();
				//封装对象
				files.add(serverFileName);	
			}
		}
		return files;
	}
	
//	public String getFileSuffix(String fileName){
//		if(fileName==null||fileName.trim().equals("")){
//			return "";
//		}
//		int dotPos=fileName.lastIndexOf(".");
//		if(dotPos!=-1){
//			return fileName.substring(dotPos);
//		}
//		return "";
//	}
	
	/**
	 * 处理邮件正文的工具方法 A
	 */
	private StringBuffer getContent(Part part,StringBuffer result) throws MessagingException, IOException{
		if(part.isMimeType("multipart/*")){
			Multipart p=(Multipart) part.getContent();
			int count=p.getCount();
			if(count>1)count=1;
			for(int i=0;i<count;i++){
				BodyPart bp=p.getBodyPart(i);
				getContent(bp, result);
			}
		}else if(part.isMimeType("text/*")){
			result.append(part.getContent());
		}
		return result;
	}
	
	/**
	 * 获取内容 A
	 */
	private String getContent(Message m) throws MessagingException, IOException{
		StringBuffer sb=new StringBuffer("");
		return getContent(m,sb).toString();
	}
	
	/**
	 * 是否已经读取
	 */
	private boolean hasRead(Message m) throws MessagingException{
		Flags flags=m.getFlags();
		return flags.contains(Flags.Flag.SEEN);
	}
	
	/**
	 * 获取所有接收人
	 */
	public List<String> getAllRecipients(Message m) throws MessagingException{
		Address[] addresses=m.getAllRecipients();
		return getAddresses(addresses);
	}
	
	/**
	 * 获取发送人
	 */
	public String getSender(Message m) throws UnsupportedEncodingException, MessagingException{
		Address[] addresses=m.getFrom();
		return MimeUtility.decodeText(addresses[0].toString());
	}
	
	/**
	 * @return 获取到地址
	 */
	private List<String> getAddresses(Address[] addresses) {
		List<String> result=new ArrayList<>();
		if(addresses==null){
			return result;
		}
		for(Address str:addresses){
			result.add(str.toString());
		}
		return result;
	}

	public String getAccount() {
		return account;
	}
	public void setAccount(String account) {
		this.account = account;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getPop3Host() {
		return pop3Host;
	}
	public void setPop3Host(String pop3Host) {
		this.pop3Host = pop3Host;
	}
	public int getPop3Port() {
		return pop3Port;
	}
	public void setPop3Port(int pop3Port) {
		this.pop3Port = pop3Port;
	}
}