Java Mail 发送邮件

package com.eastpro.batch.biz;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
import java.security.spec.X509EncodedKeySpec;
public class SendMail {
  private MimeMessage mimeMsg; //MIME mail object
  private Session session;
  private Properties props; //system property
  private boolean needAuth = false;
  private String username = "";
  private String password = "";
  private Multipart mp; //Multipart ,存放信件 title\内容\附件等
  public SendMail(String smtp) {
    setSmtpHost(smtp);
    createMimeMessage();
  }
  /**
   * @param hostName String
   */
  public void setSmtpHost(String hostName) {
    System.out.println("sytem属性：mail.smtp.host = " + hostName);
    if (props == null) {
      props = System.getProperties();
    }
    props.put("mail.smtp.host", hostName); //SMTP主机
  }
  /**
   * @return boolean
   */
  public boolean createMimeMessage() {
    try {
      System.out.println("session begin-------");
      session = Session.getInstance(props, null);
    }
    catch (Exception e) {
      System.err.println("Session.getInstance faild！" + e);
      return false;
    }
    System.out.println("MimeMessage begin-------！");
    try {
      mimeMsg = new MimeMessage(session);
      mp = new MimeMultipart();
      return true;
    }
    catch (Exception e) {
      System.err.println("MimeMessage fiald！" + e);
  &n