如何写一个JAVA类可以实现邮件发送功能,也可以实现群发功能

[color=red][/color]

[code="java"]package byd.core;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.nio.charset.Charset;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import sun.misc.BASE64Encoder;

/**

该类使用Socket连接到邮件服务器，并实现了向指定邮箱发送邮件及附件的功能。
@author Kou Hongtao
*/
public class Email {
/**
- 换行符 */ private static final String LINE_END = "\r\n";
/**
- 值为“true”输出高度信息（包括服务器响应信息），值为“ false”则不输出调试信息。 */ private boolean isDebug = true;
/**
- 值为“true”则在发送邮件{@link Mail#send()} 过程中会读取服务器端返回的消息，
- 并在邮件发送完毕后将这些消息返回给用户。 */ private boolean isAllowReadSocketInfo = true;
/**
- 邮件服务器地址 */ private String host;
/**
- 发件人邮箱地址 */ private String from;
/**
- 收件人邮箱地址 */ private List to;
/**
- 抄送地址 */ private List cc;
/**
- 暗送地址 */ private List bcc;
/**
- 邮件主题 */ private String subject;
/**
- 用户名 */ private String user;
/**
- 密码 */ private String password;
/**
- MIME邮件类型 */ private String contentType;
/**
- 用来绑定多个邮件单元{@link #partSet}
- 的分隔标识，我们可以将邮件的正文及每一个附件都看作是一个邮件单元。 */ private String boundary;
/**
- 邮件单元分隔标识符，该属性将用来在邮件中作为分割各个邮件单元的标识。 */ private String boundaryNextPart;
/**
- 传输邮件所采用的编码 */ private String contentTransferEncoding;
/**
- 设置邮件正文所用的字符集 */ private String charset;
/**
- 内容描述 */ private String contentDisposition;
/**
- 邮件正文 */ private String content;
/**
- 发送邮件日期的显示格式 */ private String simpleDatePattern;
/**
- 附件的默认MIME类型 */ private String defaultAttachmentContentType;
/**
- 邮件单元的集合，用来存放正文单元和所有的附件单元。 */ private List partSet;
private List alternativeList;
private String mixedBoundary;
private String mixedBoundaryNextPart;
/**
- 不同类型文件对应的{@link MIME} 类型映射。在添加附件
- {@link #addAttachment(String)} 时，程序会在这个映射中查找对应文件的
- {@link MIME} 类型，如果没有，则使用
- {@link #defaultAttachmentContentType} 所定义的类型。 */ private static Map contentTypeMap;
private static enum TextType {
PLAIN("plain"), HTML("html");
```
private String v;

private TextType(String v) {
    this.v = v;
}

public String getValue() {
    return this.v;
}
```
}
static {
// MIME Media Types
contentTypeMap = new HashMap();
contentTypeMap.put("xls", "application/vnd.ms-excel");
contentTypeMap.put("xlsx", "application/vnd.ms-excel");
contentTypeMap.put("xlsm", "application/vnd.ms-excel");
contentTypeMap.put("xlsb", "application/vnd.ms-excel");
contentTypeMap.put("doc", "application/msword");
contentTypeMap.put("dot", "application/msword");
contentTypeMap.put("docx", "application/msword");
contentTypeMap.put("docm", "application/msword");
contentTypeMap.put("dotm", "application/msword");
}
/**
- 该类用来实例化一个正文单元或附件单元对象，他继承了 {@link Mail}
- ，在这里制作这个子类主要是为了区别邮件单元对象和邮件服务对象，使程序易读一些。
- 这些邮件单元全部会放到partSet 中，在发送邮件 {@link #send()}时, 程序会调用
- {@link #getAllParts()} 方法将所有的单元合并成一个符合MIME格式的字符串。
- @author Kou Hongtao */ private class MailPart extends Email { public MailPart() { } }
/**
- 默认构造函数 */ public Email() { defaultAttachmentContentType = "application/octet-stream"; simpleDatePattern = "yyyy-MM-dd HH:mm:ss"; boundary = "--=_NextPart_zlz_3907_" + System.currentTimeMillis(); boundaryNextPart = "--" + boundary; contentTransferEncoding = "base64"; contentType = "multipart/mixed"; charset = Charset.defaultCharset().name(); partSet = new ArrayList(); alternativeList = new ArrayList(); to = new ArrayList(); cc = new ArrayList(); bcc = new ArrayList(); mixedBoundary = "=NextAttachment_zlz_" + System.currentTimeMillis(); mixedBoundaryNextPart = "--" + mixedBoundary; }
/**
- 根据指定的完整文件名在 {@link #contentTypeMap} 中查找其相应的MIME类型，
- 如果没找到，则返回 {@link #defaultAttachmentContentType}
- 所指定的默认类型。
- @param fileName
- 文件名
- @return 返回文件对应的MIME类型。
  */
  private String getPartContentType(String fileName) {
  String ret = null;
  if (null != fileName) {
  int flag = fileName.lastIndexOf(".");
  if (0 <= flag && flag < fileName.length() - 1) {
  fileName = fileName.substring(flag + 1);
  }
  ret = contentTypeMap.get(fileName);
  }
  if (null == ret) {
  ret = defaultAttachmentContentType;
  }
  return ret;
  }
/**
- 将给定字符串转换为base64编码的字符串
- @param str
- 需要转码的字符串
- @param charset
- 原字符串的编码格式
- @return base64编码格式的字符 */ private String toBase64(String str, String charset) { if (null != str) { try { return toBase64(str.getBytes(charset)); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } return ""; }
/**
- 将指定的字节数组转换为base64格式的字符串
- @param bs
- 需要转码的字节数组
- @return base64编码格式的字符 */ private String toBase64(byte[] bs) { return new BASE64Encoder().encode(bs); }
/**
- 将给定字符串转换为base64编码的字符串
- @param str
- 需要转码的字符串
- @return base64编码格式的字符 */ private String toBase64(String str) { return toBase64(str, Charset.defaultCharset().name()); }
/**
- 将所有的邮件单元按照标准的MIME格式要求合并。
- @return 返回一个所有单元合并后的字符串。
  */
  private String getAllParts() {
  StringBuilder sbd = new StringBuilder(LINE_END);
  sbd.append(mixedBoundaryNextPart);
  sbd.append(LINE_END);
  sbd.append("Content-Type: ");
  sbd.append("multipart/alternative");
  sbd.append(";");
  sbd.append("boundary=\"");
  sbd.append(boundary).append("\""); // 邮件类型设置
  sbd.append(LINE_END);
  sbd.append(LINE_END);
  sbd.append(LINE_END);
  addPartsToString(alternativeList, sbd, getBoundaryNextPart());
  sbd.append(getBoundaryNextPart()).append("--");
  sbd.append(LINE_END);
  addPartsToString(partSet, sbd, mixedBoundaryNextPart);
  sbd.append(LINE_END);
  sbd.append(mixedBoundaryNextPart).append("--");
  sbd.append(LINE_END);
  // sbd.append(boundaryNextPart).
  // append(LINE_END);
  alternativeList.clear();
  partSet.clear();
  return sbd.toString();
  }
private void addPartsToString(List list, StringBuilder sbd,
String nextPartString) {
int partCount = list.size();
for (int i = 0; i < partCount; i++) {
Email attachment = list.get(i);
String attachmentContent = attachment.getContent();
if (null != attachmentContent && 0 < attachmentContent.length()) {
sbd.append(nextPartString).append(LINE_END);
sbd.append("Content-Type: ");
sbd.append(attachment.getContentType());
sbd.append(LINE_END);
sbd.append("Content-Transfer-Encoding: ");
sbd.append(attachment.getContentTransferEncoding());
sbd.append(LINE_END);
String cd = attachment.getContentDisposition();
if (null != cd) {
sbd.append("Content-Disposition: ");
sbd.append(cd);
sbd.append(LINE_END);
}
```
        sbd.append(LINE_END);
        sbd.append(attachmentContent);
        sbd.append(LINE_END);
    }
}
```
}
/**
- 添加邮件正文单元 */ private void addContent() { if (null != content) { MailPart part = new MailPart(); part.setContent(toBase64(content)); part.setContentType("text/plain;charset=\"" + charset + "\""); alternativeList.add(part); } }
private String listToMailString(List mailAddressList) {
StringBuilder sbd = new StringBuilder();
if (null != mailAddressList) {
int listSize = mailAddressList.size();
for (int i = 0; i < listSize; i++) {
if (0 != i) {
sbd.append(";");
}
sbd.append("<").append(mailAddressList.get(i)).append(">");
}
}
return sbd.toString();
}
private List getrecipient() {
List list = new ArrayList();
list.addAll(to);
list.addAll(cc);
list.addAll(bcc);
return list;
}
/**
- 添加超文本内容
- @param text */ public void addHtmlContent(String text) { addContent(text, TextType.HTML); }
/**
- 添加纯文本内容
- @param text */ public void addTextContent(String text) { addContent(text, TextType.PLAIN); }
private void addContent(String text, TextType type) {
if (null != text) {
MailPart part = new MailPart();
part.setContent(toBase64(text));
part.setContentType("text/" + type.getValue() + ";charset=\""
+ charset + "\"");
alternativeList.add(part);
}
}
/**
- 添加一个附件单元
- @param filePath
- 文件路径 */ public void addAttachment(String filePath) { addAttachment(filePath, null); }
public void addTo(String mailAddress) {
this.to.add(mailAddress);
}
public void addCc(String mailAddress) {
this.cc.add(mailAddress);
}
public void addBcc(String mailAddress) {
this.bcc.add(mailAddress);
}
/**
- 添加一个附件单元
- @param filePath
- 文件路径
- @param charset
- 文件编码格式 */ public void addAttachment(String filePath, String charset) { if (null != filePath && filePath.length() > 0) { File file = new File(filePath); try { addAttachment(file.getName(), new FileInputStream(file), charset); } catch (FileNotFoundException e) { System.out.println("错误：" + e.getMessage()); System.exit(1); } } }
/**
- 添加一个附件单元
- @param fileName
- 文件名
- @param attachmentStream
- 文件流
- @param charset
- ```
       文件编码格式
```
  */
  public void addAttachment(String fileName, InputStream attachmentStream,
  String charset) {
  try {
```
byte[] bs = null;
if (null != attachmentStream) {
    int buffSize = 1024;
    byte[] buff = new byte[buffSize];
    byte[] temp;
    bs = new byte[0];
    int readTotal = 0;
    while (-1 != (readTotal = attachmentStream.read(buff))) {
        temp = new byte[bs.length];
        System.arraycopy(bs, 0, temp, 0, bs.length);
        bs = new byte[temp.length + readTotal];
        System.arraycopy(temp, 0, bs, 0, temp.length);
        System.arraycopy(buff, 0, bs, temp.length, readTotal);
    }
}

if (null != bs) {
    MailPart attachmentPart = new MailPart();
    charset = null != charset ? charset : Charset.defaultCharset()
            .name();
    String contentType = getPartContentType(fileName)
            + ";name=\"=?" + charset + "?B?" + toBase64(fileName)
            + "?=\"";
    attachmentPart.setCharset(charset);
    attachmentPart.setContentType(contentType);
    attachmentPart.setContentDisposition("attachment;filename=\"=?"
            + charset + "?B?" + toBase64(fileName) + "?=\"");
    attachmentPart.setContent(toBase64(bs));
    partSet.add(attachmentPart);
}
```
  } catch (Exception e) {
  e.printStackTrace();
  } finally {
  if (null != attachmentStream) {
  try {
  attachmentStream.close();
  attachmentStream = null;
  } catch (IOException e) {
  e.printStackTrace();
  }
  }
```
Runtime.getRuntime().gc();
Runtime.getRuntime().runFinalization();
```
  }
  }
/**
- 发送邮件
- @return 邮件服务器反回的信息
  */
  public String send() {
  // 对象申明
  // 当邮件发送完毕后，以下三个对象（Socket、
  // PrintWriter,
  // BufferedReader）需要关闭。
  Socket socket = null;
  PrintWriter pw = null;
  BufferedReader br = null;
  try {
  socket = new Socket(host, 25);
  pw = new PrintWriter(socket.getOutputStream());
  br = new BufferedReader(new InputStreamReader(socket
  .getInputStream()));
```
StringBuilder infoBuilder = new StringBuilder(
        "\nServer info: \n------------\n");

// 与服务器建立连接
pw.write("HELO ".concat(host).concat(LINE_END)); // 连接到邮件服务
if (!readResponse(pw, br, infoBuilder, "220"))
    return infoBuilder.toString();

pw.write("AUTH LOGIN".concat(LINE_END)); // 登录
if (!readResponse(pw, br, infoBuilder, "250"))
    return infoBuilder.toString();

pw.write(toBase64(user).concat(LINE_END)); // 输入用户名
if (!readResponse(pw, br, infoBuilder, "334"))
    return infoBuilder.toString();

pw.write(toBase64(password).concat(LINE_END)); // 输入密码
if (!readResponse(pw, br, infoBuilder, "334"))
    return infoBuilder.toString();

pw.write("MAIL FROM:<" + from + ">" + LINE_END); // 发件人邮箱地址
if (!readResponse(pw, br, infoBuilder, "235"))
    return infoBuilder.toString();

List<String> recipientList = getrecipient();
// 收件邮箱地址
for (int i = 0; i < recipientList.size(); i++) {
    pw.write("RCPT TO:<" + recipientList.get(i) + ">" + LINE_END);
    if (!readResponse(pw, br, infoBuilder, "250"))
        return infoBuilder.toString();
}
// System.out.println(
// getAllSendAddress());

pw.write("DATA" + LINE_END); // 开始输入邮件
if (!readResponse(pw, br, infoBuilder, "250"))
    return infoBuilder.toString();

flush(pw);

// 设置邮件头信息
StringBuffer sbf = new StringBuffer("From: <" + from + ">"
        + LINE_END); // 发件人
sbf.append("To: " + listToMailString(to) + LINE_END);// 收件人
sbf.append("Cc: " + listToMailString(cc) + LINE_END);// 收件人
sbf.append("Bcc: " + listToMailString(bcc) + LINE_END);// 收件人
sbf.append("Subject: " + subject + LINE_END);// 邮件主题
SimpleDateFormat sdf = new SimpleDateFormat(simpleDatePattern);
sbf.append("Date: ").append(sdf.format(new Date()));
sbf.append(LINE_END); // 发送时间
sbf.append("Content-Type: ");
sbf.append(contentType);
sbf.append(";");
sbf.append("boundary=\"");
sbf.append(mixedBoundary).append("\""); // 邮件类型设置
sbf.append(LINE_END);
// sbf.append(
// "This is a multi-part message in MIME format."
// );
// sbf.append(LINE_END);

// 添加邮件正文单元
addContent();

// 合并所有单元，正文和附件。
sbf.append(getAllParts());

// System.out.println(
// "///////////\n" +
// sbf.toString() +
// "///////////////\n");

// 发送
sbf.append(LINE_END).append(".").append(LINE_END);
pw.write(sbf.toString());
readResponse(pw, br, infoBuilder, "354");
flush(pw);

// QUIT退出
pw.write("QUIT" + LINE_END);
if (!readResponse(pw, br, infoBuilder, "250"))
    return infoBuilder.toString();
flush(pw);

return infoBuilder.toString();
```
  } catch (Exception e) {
  e.printStackTrace();
  return "Exception:>" + e.getMessage();
  } finally {
  // 释放资源
  try {
  if (null != socket)
  socket.close();
  if (null != pw)
  pw.close();
  if (null != br)
  br.close();
  } catch (IOException e) {
  e.printStackTrace();
  }
```
// this.to.clear();
// this.cc.clear();
// this.bcc.clear();
this.partSet.clear();
```
  }
}
/**
- 将SMTP命令发送到邮件服务器
- @param pw
- 邮件服务器输入流 */ private void flush(PrintWriter pw) { if (!isAllowReadSocketInfo) { pw.flush(); } }
/**
- 读取邮件服务器的响应信息
- @param pw
- 邮件服务器输入流
- @param br
- 邮件服务器输出流
- @param infoBuilder
- 用来存放服务器响应信息的字符串缓冲
- @param msgCode
- @return
- @throws IOException */ private boolean readResponse(PrintWriter pw, BufferedReader br, StringBuilder infoBuilder, String msgCode) throws IOException { if (isAllowReadSocketInfo) { pw.flush(); String message = br.readLine(); infoBuilder.append("SERVER:/>"); infoBuilder.append(message).append(LINE_END); if (null == message || 0 > message.indexOf(msgCode)) { System.out.println("ERROR: " + message); pw.write("QUIT".concat(LINE_END)); pw.flush(); return false; } if (isDebug) { System.out.println("DEBUG:/>" + msgCode + "/" + message); } } return true; }
public String getBoundaryNextPart() {
return boundaryNextPart;
}
public void setBoundaryNextPart(String boundaryNextPart) {
this.boundaryNextPart = boundaryNextPart;
}
public String getDefaultAttachmentContentType() {
return defaultAttachmentContentType;
}
public void setDefaultAttachmentContentType(
String defaultAttachmentContentType) {
this.defaultAttachmentContentType = defaultAttachmentContentType;
}
public String getHost() {
return host;
}
public void setHost(String host) {
this.host = host;
}
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public List getTo() {
return to;
}
public void setTo(List to) {
this.to = to;
}
public String getSubject() {
return subject;
}
public void setSubject(String subject) {
this.subject = subject;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getContentType() {
return contentType;
}
public void setContentType(String contentType) {
this.contentType = contentType;
}
public String getBoundary() {
return boundary;
}
public void setBoundary(String boundary) {
this.boundary = boundary;
}
public String getContentTransferEncoding() {
return contentTransferEncoding;
}
public void setContentTransferEncoding(String contentTransferEncoding) {
this.contentTransferEncoding = contentTransferEncoding;
}
public String getCharset() {
return charset;
}
public void setCharset(String charset) {
this.charset = charset;
}
public String getContentDisposition() {
return contentDisposition;
}
public void setContentDisposition(String contentDisposition) {
this.contentDisposition = contentDisposition;
}
public String getSimpleDatePattern() {
return simpleDatePattern;
}
public void setSimpleDatePattern(String simpleDatePattern) {
this.simpleDatePattern = simpleDatePattern;
}
public String getContent() {
return content;
}
/**
- @param content
- @deprecated 请参见 {@link #addTextContent(String)} 和
- {@link #addHtmlContent(String)} */ public void setContent(String content) { this.content = content; }
public boolean isAllowReadSocketInfo() {
return isAllowReadSocketInfo;
}
public void setAllowReadSocketInfo(boolean isAllowReadSocketInfo) {
this.isAllowReadSocketInfo = isAllowReadSocketInfo;
}
/**
- @param args
  */
  public static void main(String[] args) {
  // 应用示例：线程化发送邮件
  new Thread() {
  @Override
  public void run() {
  System.out.println("SENDER-" + this.getId() + ":/>"
  + "开始发送邮件...");
```
    // 创建邮件对象
    Email mail = new Email();
    mail.setHost("smtp.byd.com"); // 邮件服务器地址
    mail.setFrom("kou.hongtao@byd.com"); // 发件人邮箱
    mail.addTo("kou.hongtao@byd.com"); // 收件人邮箱
    mail.addCc("zhao.xiaowei@byd.com");
    mail.addBcc("");
    mail.setSubject("研发物料邮件发送测试"); // 邮件主题
    mail.setUser("kou.hongtao"); // 用户名
    mail.setPassword("byd@user"); // 密码

    // 邮件正文
    mail.addHtmlContent("<h3>研发物料邮件测试，请不要回复！</h3>");

   // mail.addAttachment("add.js"); // 添加附件

    System.out.println(mail.send()); // 发送

    System.out.println("SENDER-" + this.getId() + ":/>"
            + "邮件已发送完毕！");
}
```
  }.start();
}
}

[/code]