SendMail.java Source code

Introduction

Here is the source code for SendMail.java

Source

/*
 * Copyright (c) 2004 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 3nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose,
 * including teaching and use in open-source projects.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book, 
 * please visit http://www.davidflanagan.com/javaexamples3.
 */
//package je3.net;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.URL;
import java.net.URLConnection;

/**
 * This program sends e-mail using a mailto: URL
 */
public class SendMail {
    public static void main(String[] args) {
        try {
            // If the user specified a mailhost, tell the system about it.
            if (args.length >= 1)
                System.getProperties().put("mail.host", args[0]);

            // A Reader stream to read from the console
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

            // Ask the user for the from, to, and subject lines
            System.out.print("From: ");
            String from = in.readLine();
            System.out.print("To: ");
            String to = in.readLine();
            System.out.print("Subject: ");
            String subject = in.readLine();

            // Establish a network connection for sending mail
            URL u = new URL("mailto:" + to); // Create a mailto: URL
            URLConnection c = u.openConnection(); // Create its URLConnection
            c.setDoInput(false); // Specify no input from it
            c.setDoOutput(true); // Specify we'll do output
            System.out.println("Connecting..."); // Tell the user
            System.out.flush(); // Tell them right now
            c.connect(); // Connect to mail host
            PrintWriter out = // Get output stream to host
                    new PrintWriter(new OutputStreamWriter(c.getOutputStream()));

            // We're talking to the SMTP server now.
            // Write out mail headers. Don't let users fake the From address
            out.print("From: \"" + from + "\" <" + System.getProperty("user.name") + "@"
                    + InetAddress.getLocalHost().getHostName() + ">\r\n");
            out.print("To: " + to + "\r\n");
            out.print("Subject: " + subject + "\r\n");
            out.print("\r\n"); // blank line to end the list of headers

            // Now ask the user to enter the body of the message
            System.out.println("Enter the message. " + "End with a '.' on a line by itself.");
            // Read message line by line and send it out.
            String line;
            for (;;) {
                line = in.readLine();
                if ((line == null) || line.equals("."))
                    break;
                out.print(line + "\r\n");
            }

            // Close (and flush) the stream to terminate the message
            out.close();
            // Tell the user it was successfully sent.
            System.out.println("Message sent.");
        } catch (Exception e) { // Handle any exceptions, print error message.
            System.err.println(e);
            System.err.println("Usage: java SendMail [<mailhost>]");
        }
    }
}