要完成Java群发邮件功能，首先须加入mail.jar和activation.jar这两个包

下面是邮件的例子:

import java.io.File;
import java.util.Properties;
import java.util.Vector;
import javax.mail.internet.MimeUtility;
/**
* 发送邮件的信息类
* @author 仇志鹏
* @version 2016.10.19
*
*/
public class MailSenderInfo {
// 发送邮件的服务器的IP和端口
private String mailServerHost;
private String mailServerPort = “25”;
// 邮件发送者的地址
private String fromAddress;
// 邮件接收者的地址
private String[] toAddress;
// 登陆邮件发送服务器的用户名和密码
private String userName;
private String password;
// 是否需要身份验证
private boolean validate = false;
// 邮件主题
private String subject;
// 邮件的文本内容
private String content;
// 邮件附件的文件名
private String fileName = “” ;
//附件文件集合
private Vector file = new Vector() ;

/**
* 获得邮件会话属性
* @return
*/
public Properties getProperties(){
Properties p = new Properties();
p.put(“mail.smtp.host”, this.mailServerHost);
p.put(“mail.smtp.port”, this.mailServerPort);
p.put(“mail.smtp.auth”, validate ? “true” : “false”);
return p;
}
public String getMailServerHost() {
return mailServerHost;
}
public void setMailServerHost(String mailServerHost) {
this.mailServerHost = mailServerHost;
}
public String getMailServerPort() {
return mailServerPort;
}
public void setMailServerPort(String mailServerPort) {
this.mailServerPort = mailServerPort;
}
public boolean isValidate() {
return validate;
}
public void setValidate(boolean validate) {
this.validate = validate;
}
public String getFromAddress() {
return fromAddress;
}
public void setFromAddress(String fromAddress) {
this.fromAddress = fromAddress;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String[] getToAddress() {
return toAddress;
}
public void setToAddress(String[] toAddress) {
this.toAddress = toAddress;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getSubject() {
return subject;
}
public void setSubject(String subject) {
this.subject = subject;
}
public String getContent() {
return content;
}
public void setContent(String textContent) {
this.content = textContent;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public Vector getFile() {
return file;
}
public void setFile(Vector file) {
this.file = file;
}
/**
*
* 方法说明：把主题转换为中文
* 输入参数：String strText
* 返回类型：
*/
public String transferChinese(String strText) {
try {
strText = MimeUtility.encodeText(new String(strText.getBytes(),
“GB2312”), “GB2312”, “B”);
} catch (Exception e) {
e.printStackTrace();
}
return strText;
}
}
———————————————————
import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;
/**
* 发邮件的身份验证器
* @author 仇志鹏
* @version 2016.10.19
*
*/
public class MyAuthenticator extends Authenticator{
String userName=null;
String password=null;

public MyAuthenticator(){

}
public MyAuthenticator(String username, String password) {
this.userName = username;
this.password = password;
}
protected PasswordAuthentication getPasswordAuthentication(){
return new PasswordAuthentication(userName, password);
}
}
———————————————————————
import java.io.File;
import java.util.Date;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.Address;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class SimpleMailSender {
/** *//**
* 以文本格式发送邮件
* @param mailInfo 待发送的邮件的信息
*/
public boolean sendTextMail(MailSenderInfo mailInfo) {
// 判断是否需要身份认证
MyAuthenticator authenticator = null;
Properties pro = mailInfo.getProperties();
if (mailInfo.isValidate()) {
// 如果需要身份认证，则创建一个密码验证器
authenticator = new MyAuthenticator(mailInfo.getUserName(), mailInfo.getPassword());
}
// 根据邮件会话属性和密码验证器构造一个发送邮件的session
Session sendMailSession = Session.getDefaultInstance(pro,authenticator);
try {
// 根据session创建一个邮件消息
Message mailMessage = new MimeMessage(sendMailSession);
// 创建邮件发送者地址 authenticator
Address from = new InternetAddress(mailInfo.getFromAddress());
// 设置邮件消息的发送者
mailMessage.setFrom(from);
// 创建邮件的接收者地址，并设置到邮件消息中
String[] mailToAddress = mailInfo.getToAddress() ;
int len = mailToAddress.length ;
Address to[] = new InternetAddress[len] ;
for(int i=0;i<len;i++){
to[i] = new InternetAddress(mailToAddress[i]) ;
}
// Message.RecipientType.TO属性表示接收者的类型为TO
//TO表示主要接收人，CC表示抄送人，BCC表示秘密抄送人。
mailMessage.setRecipients(Message.RecipientType.TO,to);
// 设置邮件消息的主题
mailMessage.setSubject(mailInfo.getSubject());
// 设置邮件消息发送的时间
mailMessage.setSentDate(new Date());
// 设置邮件消息的主要内容
String mailContent = mailInfo.getContent();
mailMessage.setText(mailContent);
// 发送邮件
Transport.send(mailMessage);
return true;
} catch (MessagingException ex) {
ex.printStackTrace();
}
return false;
}

/** *//**
* 以HTML格式发送邮件
* @param mailInfo 待发送的邮件信息
*/
public boolean sendHtmlMail(MailSenderInfo mailInfo){
// 判断是否需要身份认证
MyAuthenticator authenticator = null;
Properties pro = mailInfo.getProperties();
//如果需要身份认证，则创建一个密码验证器
if (mailInfo.isValidate()) {
authenticator = new MyAuthenticator(mailInfo.getUserName(), mailInfo.getPassword());
}
// 根据邮件会话属性和密码验证器构造一个发送邮件的session
Session sendMailSession = Session.getDefaultInstance(pro,authenticator);
try {
// 根据session创建一个邮件消息
Message mailMessage = new MimeMessage(sendMailSession);
// 创建邮件发送者地址
Address from = new InternetAddress(mailInfo.getFromAddress());
// 设置邮件消息的发送者
mailMessage.setFrom(from);
// 创建邮件的接收者地址，并设置到邮件消息中
String[] mailToAddress = mailInfo.getToAddress() ;
int len = mailToAddress.length ;
Address to[] = new InternetAddress[len] ;
for(int i=0;i<len;i++){
to[i] = new InternetAddress(mailToAddress[i]) ;
}
// Message.RecipientType.TO属性表示接收者的类型为TO
//mailMessage.setRecipient(Message.RecipientType.TO, to) ;
mailMessage.setRecipients(Message.RecipientType.TO,to);
// 设置邮件消息的主题
mailMessage.setSubject(mailInfo.getSubject());
// 设置邮件消息发送的时间
mailMessage.setSentDate(new Date());
// MiniMultipart类是一个容器类，包含MimeBodyPart类型的对象
Multipart mainPart = new MimeMultipart();
// 创建一个包含HTML内容的MimeBodyPart
BodyPart html = new MimeBodyPart();
// 设置HTML内容
html.setContent(mailInfo.getContent(), “text/html; charset=utf-8″);
mainPart.addBodyPart(html);
//向multipart中添加附件
Vector file = mailInfo.getFile() ;
String fileName = mailInfo.getFileName() ;
Enumeration efile = file.elements() ;
while(efile.hasMoreElements()){
MimeBodyPart mdpFile = new MimeBodyPart() ;
fileName = efile.nextElement().toString() ;
FileDataSource fds = new FileDataSource(fileName) ;
mdpFile.setDataHandler(new DataHandler(fds)) ;
//这个方法可以解决乱码问题
String fileName1 = new String(fds.getName().getBytes(),”ISO-8859-1”) ;
mdpFile.setFileName(fileName1) ;
mainPart.addBodyPart(mdpFile) ;
}
file.removeAllElements() ;
// 将MiniMultipart对象设置为邮件内容
mailMessage.setContent(mainPart);
// 发送邮件
Transport.send(mailMessage);
return true;
} catch (Exception ex) {
ex.printStackTrace();
}
return false;
}
}
————————————————————————————–
import java.io.File;
import java.util.Vector;

import com.sun.mail.util.MailSSLSocketFactory;

public class SendMail {
public static void main(String[] args) {
try {
MailSenderInfo mailInfo = new MailSenderInfo();
MailSSLSocketFactory sf = new MailSSLSocketFactory();
sf.setTrustAllHosts(true);

// 设置邮件服务器类型 smtp.qq.com smtp.exmail.qq.com
mailInfo.setMailServerHost(“smtp.qq.com”);
//设置端口号 25
mailInfo.setMailServerPort(“587”);
//设置是否验证
mailInfo.setValidate(true);
//设置用户名、密码、发送人地址
mailInfo.setUserName(“1909083200”); // 不用带@qq.com
mailInfo.setPassword(“dolsgbvwttttchhd”);// 这个是在邮箱中获取的授权码
mailInfo.setFromAddress(“1909083200@qq.com”); //这个必须填完整
/**
* 附件
*/
Vector file = new Vector() ;
File f1 = new File(“d:/1.txt”) ;
file.add(f1) ;
mailInfo.setFile(file) ;
/**
* 收件人邮箱
* wuhaixu449261417@sina.com
*/
String[] mailToAddress = {“gentlemango@vip.qq.com”} ;
mailInfo.setToAddress(mailToAddress);
mailInfo.setSubject(“测试”);
mailInfo.setContent(“注册地址 百度“);
// 这个类主要来发送邮件
SimpleMailSender sms = new SimpleMailSender();
// sms.sendTextMail(mailInfo);// 发送文体格式
if(sms.sendHtmlMail(mailInfo)){
System.out.println(“mail send True!”);
}// 发送html格式
else{
System.out.println(“mail send False!”);
}
} catch (Exception e) {
e.printStackTrace() ;
}
}
}

以上实现了javamail的群发送功能。