准备内容
这里仅以扣扣邮箱为例，首先，登录扣扣邮箱把imap协议开启，并记下授权码（这个过程，不会请百度），这个授权码是用来代替密码登陆的，注意：扣扣邮箱开启imap协议必须先设置独立密码。
下载javamail的jar包填入工程中。
注意事项
应该用SSL登录，一般的方式登陆（http）会进不去，javamail把邮件分解成若干个结构（依次递归分析就可以了），这个代码理会详细展示。
附代码：
package test;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import java.io.*;
import java.security.Security;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
/**
* Created by rightHead on 2016/8/15.
*/
public class MailTest {
private String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
private List<Bean> list;
private Bean bean;
private String cate = "E:/";
private String name, pass; // 邮箱地址 和 授权码
public List<Bean> getList() {
return list;
}
public void setParameter(String name, String pass, String road){
cate = road;
this.name = name;
this.pass = pass;
}
public void start(){
list = new ArrayList<>();
getMails(name, pass);
}
public boolean connect(){
return connectTest(name, pass);
}
private boolean connectTest(String username, String pass){
Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
Properties props = System.getProperties();
props.setProperty("mail.imap.socketFactory.class", SSL_FACTORY);
props.setProperty("mail.imap.socketFactory.fallback", "false");
props.setProperty("mail.store.protocol", "imap");
props.setProperty("mail.imap.host", "imap.qq.com");
props.setProperty("mail.imap.port", "993");
props.setProperty("mail.imap.socketFactory.port", "993");
Session session = Session.getDefaultInstance(props,null);
URLName urln = new URLName("imap","imap.qq.com",993,null,
username, pass);
boolean f = false;
Folder inbox = null;
try{
Store store = session.getStore(urln);
store.connect();
inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
f = inbox.exists();
}catch (MessagingException e){
e.printStackTrace();
}
return f;
}
public String getMails(String username,String pass){
Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
Properties props = System.getProperties();
props.setProperty("mail.imap.socketFactory.class", SSL_FACTORY);
props.setProperty("mail.imap.socketFactory.fallback", "false");
props.setProperty("mail.store.protocol", "imap");
props.setProperty("mail.imap.host", "imap.qq.com");
props.setProperty("mail.imap.port", "993");
props.setProperty("mail.imap.socketFactory.port", "993");
Session session = Session.getDefaultInstance(props,null);
URLName urln = new URLName("imap","imap.qq.com",993,null,
username, pass);
Store store = null;
String msg = "";
Folder inbox = null;
try {
store = session.getStore(urln);
store.connect();
inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
FetchProfile profile = new FetchProfile();
profile.add(FetchProfile.Item.ENVELOPE);
Message[] messages = inbox.getMessages();
inbox.fetch(messages, profile);
System.out.println(messages.length);
System.out.println(inbox.getUnreadMessageCount() + "封未读邮件！");
System.out.println(inbox.getNewMessageCount() + "封新邮件!");
System.out.println("你好，即将遍历消息内容！");
for (Message m : messages){
if (m.getFlags().contains(Flags.Flag.SEEN)){
continue;
}
System.out.println("发现一封未读邮件即将分析！");
/* IMAPMessage ms = (IMAPMessage) m;
System.out.println("11");
String subject = MimeUtility.decodeText(ms.getSubject());
System.out.println("22");*/
bean = new Bean();
mailReceiver(m);
list.add(bean);
// m.setFlag(Flags.Flag.SEEN, true);
System.out.println("————-————————————————————————————");
}
} catch (MessagingException e) {
// TODO Auto-generated catch block
msg = "0";
} finally{
try {
inbox.close(false);
store.close();
} catch (MessagingException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
}finally{
return msg;
}
}
}
private void mailReceiver(Message msg)throws Exception{
// 发件人信息
System.out.println("分析邮件内容");
System.out.println("获取发件人地址");
Address[] froms = msg.getFrom();
if(froms != null) {
System.out.println("即将打印发件人地址。。。");
InternetAddress addr = (InternetAddress)froms[0];
System.out.println("发件人地址:" + addr.getAddress());
bean.setPersonAddress(addr.getAddress());
bean.setPersonName(addr.getPersonal());
System.out.println("发件人显示名:" + addr.getPersonal());
}
System.out.println("邮件主题:" + msg.getSubject());
bean.setTheme(msg.getSubject());
// getContent() 是获取包裹内容, Part相当于外包装
System.out.println("即将分析邮件内容。。。");
Object o = msg.getContent();
if(o instanceof Multipart) {
System.out.println("Multipart");
Multipart multipart = (Multipart) o ;
reMultipart(multipart);
} else if (o instanceof Part){
System.out.println("Part");
Part part = (Part) o;
rePart(part);
} else {
System.out.println("既不是Multipart也不是Part");
System.out.println("类型" + msg.getContentType());
System.out.println("内容" + msg.getContent());
}
}
/**
* @param part 解析内容
* @throws Exception
*/
private void rePart(Part part) throws MessagingException, IOException{
System.out.println("进入rePart");
if(part.getContentType().startsWith("TEXT/PLAIN")) {
System.out.println("HTML内容：" + part.getContent());
bean.setUrl((String) part.getContent());
} else {
//System.out.println("HTML内容：" + part.getContent());
}
}
/**
* @param multipart // 接卸包裹（含所有邮件内容(包裹+正文+附件)）
* @throws Exception
*/
private void reMultipart(Multipart multipart) throws Exception {
System.out.println("邮件共有" + multipart.getCount() + "部分组成");
System.out.println("即将一次处理各部分");
// 依次处理各个部分
for (int j = 0, n = multipart.getCount(); j < n; j++) {
System.out.println("处理第" + j + "部分");
Part part = multipart.getBodyPart(j);//解包, 取出 MultiPart的各个部分, 每部分可能是邮件内容,
// 也可能是另一个小包裹(MultipPart)
// 判断此包裹内容是不是一个小包裹, 一般这一部分是 正文 Content-Type: multipart/alternative
if (part.getContent() instanceof Multipart) {
System.out.println("此部分仍有小包裹，将迭代处理！");
Multipart p = (Multipart) part.getContent();// 转成小包裹
//递归迭代
reMultipart(p);
} else {
rePart(part);
}
}
}
}