java使用Socket实现SMTP协议发送邮件

本文实例为大家分享了java 利用socket实现smtp协议发送邮件的具体代码，供大家参考，具体内容如下

package mail;
 
import java.io.bufferedreader;
import java.io.ioexception;
import java.io.inputstream;
import java.io.inputstreamreader;
import java.io.outputstream;
import java.io.printwriter;
import java.io.reader;
import java.net.socket;
import java.util.arraylist;
import java.util.list;
 
import org.apache.commons.codec.binary.base64;
 
public class mail {
 
  public static void main(string[] args) throws ioexception {
    mail mail = new mail();
    mail.setsmtpserver("smtp.qq.com");
    mail.setfrommail("1344364****@qq.com");
    mail.addtomail("105648****@qq.com");
    mail.addtomail("long*****@sina.com");
    mail.setusername("134364****");
    mail.setpassword("*************");
    mail.setsubject("测试邮件");
    mail.setcontent("<h1>你好</h1><br/><img src=\"https://www.baidu.com/img/baidu_jgylogo3.gif?v=39549282.gif\" />");
    mail.setshowlog(true);
    mail.send();
    system.out.println("程序结束");
  }
 
  /** 邮件主题 **/
  private string subject;
  /** 从此地址发出 **/
  private string frommail;
  /** 用户名 **/
  private string username;
  /** 登录密码 **/
  private string password;
  /** smtp 服务器地址 **/
  private string smtpserver;
  /** smtp 服务器端口（默认：25） **/
  private int smtpport = 25;
  /** 发送到 tomail 中的所有地址 **/
  private list<string> tomail;
  /** 邮件内容 **/
  private string content;
  /** 是否显示日志 **/
  private boolean showlog;
 
  public void addtomail(string mail) {
    if (tomail == null)
      tomail = new arraylist<string>();
    tomail.add(mail);
  }
 
  public void send() {
    if (smtpserver == null) {
      throw new runtimeexception("smtpserver 不能为空");
    }
    if (username == null) {
      throw new runtimeexception("username 不能为空");
    }
    if (password == null) {
      throw new runtimeexception("password 不能为空");
    }
    if (frommail == null) {
      throw new runtimeexception("frommail 不能为空");
    }
    if (tomail == null || tomail.isempty()) {
      throw new runtimeexception("tomail 不能为空");
    }
    if (content == null || tomail.isempty()) {
      throw new runtimeexception("content 不能为空");
    }
 
    socket socket = null;
    inputstream in = null;
    outputstream out = null;
    try {
      socket = new socket(smtpserver, smtpport);
      socket.setsotimeout(3000);
      in = socket.getinputstream();
      out = socket.getoutputstream();
    } catch (ioexception e) {
      throw new runtimeexception("连接到 " + smtpserver + ":" + smtpport + " 失败", e);
    }
 
    bufferedreaderproxy reader = new bufferedreaderproxy(new inputstreamreader(in), showlog);
    printwriterproxy writer = new printwriterproxy(out, showlog);
 
    reader.showresponse();
    writer.println("helo " + smtpserver);
    reader.showresponse();
    writer.println("auth login");
    reader.showresponse();
    writer.println(new string(base64.encodebase64(username.getbytes())));
    reader.showresponse();
    writer.println(new string(base64.encodebase64(password.getbytes())));
    reader.showresponse();
    writer.println("mail from:" + frommail);
    reader.showresponse();
    for (string mail : tomail) {
      writer.println("rcpt to:" + mail);
      reader.showresponse();
    }
    writer.println("data");
    writer.println("content-type:text/html");
    if (subject != null) {
      writer.println("subject:" + subject);
    }
    writer.println("from:" + frommail);
    writer.print("to:");
    for (string mail : tomail) {
      writer.print(mail + "; ");
    }
    writer.println();
    writer.println();
    writer.println(content);
    writer.println(".");
    reader.showresponse();
    writer.println("quit");
    reader.showresponse();
    try {
      socket.close();
    } catch (ioexception e) {
      system.err.println("发送邮件完成，关闭 socket 出错：" + e.getmessage());
    }
  }
 
  public string getsubject() {
    return subject;
  }
 
  public void setsubject(string subject) {
    this.subject = subject;
  }
 
  public string getfrommail() {
    return frommail;
  }
 
  public void setfrommail(string frommail) {
    this.frommail = frommail;
  }
 
  public string getsmtpserver() {
    return smtpserver;
  }
 
  public void setsmtpserver(string smtpserver) {
    this.smtpserver = smtpserver;
  }
 
  public int getsmtpport() {
    return smtpport;
  }
 
  public void setsmtpport(int smtpport) {
    this.smtpport = smtpport;
  }
 
  public string getcontent() {
    return content;
  }
 
  public void setcontent(string content) {
    this.content = content;
  }
 
  public list<string> gettomail() {
    return tomail;
  }
 
  public void settomail(list<string> tomail) {
    this.tomail = tomail;
  }
 
  public string getusername() {
    return username;
  }
 
  public void setusername(string username) {
    this.username = username;
  }
 
  public string getpassword() {
    return password;
  }
 
  public void setpassword(string password) {
    this.password = password;
  }
 
  public boolean getshowlog() {
    return showlog;
  }
 
  public void setshowlog(boolean showlog) {
    this.showlog = showlog;
  }
 
  static class printwriterproxy extends printwriter {
    private boolean showrequest;
 
    public printwriterproxy(outputstream out, boolean showrequest) {
      super(out, true);
      this.showrequest = showrequest;
    }
 
    @override
    public void println() {
      if (showrequest)
        system.out.println();
      super.println();
    }
 
    public void print(string s) {
      if (showrequest)
        system.out.print(s);
      super.print(s);
    }
  }
 
  static class bufferedreaderproxy extends bufferedreader {
    private boolean showresponse = true;
 
    public bufferedreaderproxy(reader in, boolean showresponse) {
      super(in);
      this.showresponse = showresponse;
    }
 
    public void showresponse() {
      try {
        string line = readline();
        string number = line.substring(0, 3);
        int num = -1;
        try {
          num = integer.parseint(number);
        } catch (exception e) {
        }
        if (num == -1) {
          throw new runtimeexception("响应信息错误 : " + line);
        } else if (num >= 400) {
          throw new runtimeexception("发送邮件失败 : " + line);
        }
        if (showresponse) {
          system.out.println(line);
        }
      } catch (ioexception e) {
        system.out.println("获取响应失败");
      }
    }
 
  }
}

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