封装一下 javaMail,帐号密码配置在配置文件中，要发送的内容 和收件人列表后面再添加

封装一下 javaMail的发送邮件功能,帐号密码配置在配置文件中

采用build创建模式，创建前时可以再改变地址 ，发件人 ，发件人姓名等参数

依赖javaMail.jar包

源码： https://download.csdn.net/download/woaiqianzhige/10286709

package com.hcy;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.NoSuchProviderException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class MailTools {

	private String text = ""; // 文本内容
	private String username; // 用户账号
	private String password; // 授权码
	private String smtp; // 邮件发送服务器
	private String pop3; // 邮件接受服务器
	private String from; // 发件人
	private Set<String> to = new HashSet<String>(); // 收件人列表
	private String subject; // 主题 相当于摘要
	private String fromName; // 发件人名字
	private MyAuthenticator myAuthenticator;

	public MailTools(MailToolsBuilder build) {
		this.username = build.username;
		this.password = build.password;
		this.smtp = build.smtp;
		this.pop3 = build.pop3;
		this.from = build.from;
		this.subject = build.subject;
		this.fromName = build.fromName;
		checkNull(username, "username不能为空");
		checkNull(password, "password不能为空");

		this.myAuthenticator = new MyAuthenticator(username, password);
	}

	public void addTo(String t) {
		this.to.add(t);

	}

	public void setText(String text) {
		this.text = text;
	}

	public void addTos(Set<String> tos){
		for(String t :tos){
			this.to.add(t);
		}
	}
	// 要想发送邮件，必须要填的是 用户名 授权码 发件人 收件人 smtp
	public String sendMail() {
		checkNull(from, "from不能为空");
		checkNull(smtp, "smtp不能为空");
		if (to.isEmpty()) {
			throw new IllegalArgumentException("请输入收件人");
		}
		Properties props = System.getProperties();
		props.put("mail.smtp.host", smtp);
		props.put("mail.smtp.auth", true);

		Session session = Session.getDefaultInstance(props, myAuthenticator);
		MimeMessage msg = new MimeMessage(session);

		// 设置内容，设置标题，设置收件人
		try {
			msg.setText(text);
			msg.setFrom(new InternetAddress(from, fromName, "utf-8"));
			// 发送
			for (String t : to) {
				msg.addRecipient(Message.RecipientType.TO, new InternetAddress(
						t));
			}

			if (subject != null) {
				msg.setSubject(subject);
			}

		} catch (MessagingException e) {
			return e.getMessage();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		// 发送出去
		Transport transport = null;
		try {
			transport = session.getTransport("smtp");
		} catch (NoSuchProviderException e) {
			e.printStackTrace();
			return e.getMessage();
		}

		try {
			transport.connect();
			transport.sendMessage(msg, msg.getAllRecipients());
			transport.close();
		} catch (MessagingException e) {
			e.printStackTrace();
			return "发送失败";
		}
		return "投递成功";
	}

	/** 返回当前收件人列表的副本 */
	public Set<String> getToSet() {
		return new HashSet<String>(to);
	}

	public String sendMail(String text) {
		this.text = text;
		return sendMail();
	}

	private void checkNull(String str, String msg) {
		if (str == null) {
			throw new IllegalArgumentException(msg);
		}
	}

	/**
	 * 用于清除收件人列表
	 */
	public void clearTo() {
		to.clear();
	}

	public static class MailToolsBuilder {
		private String username; // 用户账号
		private String password; // 授权码
		private String smtp; // 邮件发送服务器
		private String pop3; // 邮件接受服务器
		private String from; // 发件人
		private String subject; // 主题 相当于摘要
		private String fromName; // 发件人名字

		/**
		 * 
		 * @param props
		 *            需要配置文件模板 mail.username mail.password mail.smtp mail.pop3
		 *            mail.fromname
		 * @throws FileNotFoundException 
		 * @throws IOException
		 * 
		 * 
		 */
		public MailToolsBuilder(String path) throws FileNotFoundException, IOException {
			Properties props = new Properties();
			props.load(new FileInputStream(path));
			init(props);
			
		}

		public MailToolsBuilder(Properties props) {
			init(props);
		}

		private void init(Properties props) {

			if (!props.containsKey("mail.username")) {
				throw new IllegalAccessError("配置文件错误：缺少mail.username");
			}
			if (!props.containsKey("mail.password")) {
				throw new IllegalAccessError("配置文件错误：缺少mail.upassword");
			}
			if (!props.containsKey("mail.smtp")) {
				throw new IllegalAccessError("配置文件错误：缺少mail.smtp");
			}
			if (!props.containsKey("mail.pop3")) {
				throw new IllegalAccessError("配置文件错误：缺少mail.pop3");
			}
			if (!props.containsKey("mail.fromname")) {
				throw new IllegalAccessError("配置文件错误：缺少mail.fromname");
			}

			this.username = props.getProperty("mail.username");
			this.password = props.getProperty("mail.password");
			this.smtp = props.getProperty("mail.smtp");
			this.pop3 = props.getProperty("mail.pop3");
			this.fromName = props.getProperty("mail.fromname");

			if (props.containsKey("mail.subject")) {
				this.subject = props.getProperty("mail.subject");
			}
			if (props.containsKey("mail.from")) {
				this.from = props.getProperty("mail.from");
			}
		}

		public MailToolsBuilder setUsername(String username) {
			this.username = username;
			return this;
		}

		public MailToolsBuilder setPassword(String password) {
			this.password = password;
			return this;
		}

		public MailToolsBuilder setSmtp(String smtp) {
			this.smtp = smtp;
			return this;
		}

		public MailToolsBuilder setPop3(String pop3) {
			this.pop3 = pop3;
			return this;
		}

		public MailToolsBuilder setTitle(String fromName) {
			this.fromName = fromName;
			return this;
		}

		public MailToolsBuilder setSubject(String subject) {
			this.subject = subject;
			return this;
		}

		public MailToolsBuilder setFrom(String from) {
			this.from = from;
			return this;
		}

		public MailTools build() {
			return new MailTools(this);
		}
	}

}

package com.hcy;

import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;

public class MyAuthenticator extends Authenticator {

	private String username, password;

	protected PasswordAuthentication getPasswordAuthentication() {
		return new PasswordAuthentication(username, password);
	}

	public MyAuthenticator(String username, String password) {
		this.username = username;
		this.password = password;
	}

}

package com.test;

import java.io.FileNotFoundException;
import java.io.IOException;

import com.hcy.MailTools;
import com.hcy.MailTools.MailToolsBuilder;

public class SendDemo { 
	public static void main(String[] args) throws FileNotFoundException, IOException {
		String to = "[email protected]";
		MailTools mailTools = new MailToolsBuilder("resouce/Mail.properties").build();
		mailTools.addTo(to);
		mailTools.setText("尊敬的用户，您本月已用流量xxx剩余流量xxx，已用话费xxx ，剩余花费xxx");		
		String str = mailTools.sendMail();
		System.out.println(str);	
		
	
	}
}

配置文件格式：  #Nessential
mail.username=
mail.password=
mail.smtp=
mail.pop3=
mail.fromname=
#Nessential
mail.from=
mail.subject=