一：条件 必须下载sun公司的JavaMail API包，地址为：http://java.sun.com/products/javamail/
我这里用的是1.2版本，将相关包(jar文件)加到CLASSPATH中
二：该程序非常简单，不需要我们考虑很多地层的东西，因为API都帮我们做好了这些事情，下面是一个简单的发邮件的Servlet：(对于熟悉的人来说，恐怕是再简单不过了的一个servlet)
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import sun.net.smtp.*;
public class SendMailServlet extends HttpServlet {
public static String MAIL_FROM = "from";
public static String MAIL_TO = "to";
public static String MAIL_SUBJECT = "subject";
public static String MAIL_BODY = "body";
public static String MAIL_HOST = "mailhost";
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
resp.setContentType("text/html; charset=gb2312");
PrintWriter out = resp.getWriter();
out.println("<form method=POST action=\"" + req.getRequestURI() + "\">");
out.println("<table>");
out.println("<tr><td>send mail server:</td>");
out.println("<td><input type=text name=" + MAIL_HOST + " size=30></td></tr>");
out.println("<tr><td>from:</td>");
out.println("<td><input type=text name=" + MAIL_FROM + " size=30></td></tr>");
out.println("<tr><td>to:</td>");
out.println("<td><input type=text name=" + MAIL_TO + " size=30></td></tr>");
out.println("<tr><td>subject:</td>");
out.println("<td><input type=text name=" + MAIL_SUBJECT + " size=30></td></tr>");
out.println("<tr><td>text:</td>");
out.println("<td><textarea name=" + MAIL_BODY + " cols=40 rows=10></textarea></td></tr>");
out.println("</table><br>");
out.println("<input type=submit value=\"Send\">");
out.println("<input type=reset value=\"Reset\">");
out.println("</form>");
out.flush();
}
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException,IOException
{
resp.setContentType("text/html; charset=gb2312");
PrintWriter out = new PrintWriter(resp.getOutputStream());
String from = req.getParameter(MAIL_FROM);
String to = req.getParameter(MAIL_TO);
String subject = req.getParameter(MAIL_SUBJECT);
String body = req.getParameter(MAIL_BODY);
String mailhost = req.getParameter(MAIL_HOST);
try
{
SmtpClient mailer = new SmtpClient(mailhost);
mailer.from(from);
mailer.to(to);
PrintStream ps = mailer.startMessage();
ps.println("From: " + from);
ps.println("To: " + to);
ps.println("Subject: " + subject);
ps.println(body);
mailer.closeServer();
out.println("Success!");
}
catch (Exception ex)
{
out.println("An error about:" + ex.getMessage());
}
out.flush();
}
public void init(ServletConfig cfg) throws ServletException
{
super.init(cfg);
}
public void destroy()
{
super.destroy();
}
}
