smtpclient.java.bak

DNS Client和SMTP Client

import java.io.*;
import java.net.*;
//本程序实现邮件传输功能
public class SMTPClient {
    public static void main(String[] args) {
        try {
            if (args.length >= 1)
		System.getProperties().put("mail.host", args[0]);
	     BufferedReader in =new BufferedReader(new InputStreamReader(System.in));
             System.out.print("From: ");
            String from = in.readLine();
            System.out.print("To: ");
            String to = in.readLine();
            System.out.print("Subject: ");
            String subject = in.readLine();
             URL u = new URL("mailto:" + to);    
            URLConnection c = u.openConnection(); 
            c.setDoInput(false);                  
            c.setDoOutput(true);                  
            System.out.println("Connecting...");  
            System.out.flush();                  
            c.connect();                         
            PrintWriter out =                     
                new PrintWriter(new OutputStreamWriter(c.getOutputStream()));
         
            out.print("From: \"" + from + "\" <" +
	        System.getProperty("user.name") + "@" + 
	        InetAddress.getLocalHost().getHostName() + ">\n");
            out.print("To: " + to + "\n");
            out.print("Subject: " + subject + "\n");
            out.print("\n");  
            System.out.println("Enter the message. " + 
			       "End with a '.' on a line by itself.");
       
            String line;
            for(;;) {
                line = in.readLine();
                if ((line == null) || line.equals(".")) break;
                out.print(line + "\n");
            }
       
            out.close();
            System.out.println("Message sent.");
        }
        catch (Exception e) {  
            System.err.println(e);
            System.err.println("Usage: java SendMail [<mailhost>]");
        }
    }
}