MailTest.java Source code

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Here is the source code for MailTest.java

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/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.util.Scanner;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingWorker;

/**
 * This program shows how to use sockets to send plain text mail messages.
 * @author Cay Horstmann
 * @version 1.11 2007-06-25
 */
public class MailTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new MailTestFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}

/**
 * The frame for the mail GUI.
 */
class MailTestFrame extends JFrame {
    public MailTestFrame() {
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        setTitle("MailTest");

        setLayout(new GridBagLayout());

        // we use the GBC convenience class of Core Java Volume 1 Chapter 9
        add(new JLabel("From:"), new GBC(0, 0).setFill(GBC.HORIZONTAL));

        from = new JTextField(20);
        add(from, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0));

        add(new JLabel("To:"), new GBC(0, 1).setFill(GBC.HORIZONTAL));

        to = new JTextField(20);
        add(to, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0));

        add(new JLabel("SMTP server:"), new GBC(0, 2).setFill(GBC.HORIZONTAL));

        smtpServer = new JTextField(20);
        add(smtpServer, new GBC(1, 2).setFill(GBC.HORIZONTAL).setWeight(100, 0));

        message = new JTextArea();
        add(new JScrollPane(message), new GBC(0, 3, 2, 1).setFill(GBC.BOTH).setWeight(100, 100));

        comm = new JTextArea();
        add(new JScrollPane(comm), new GBC(0, 4, 2, 1).setFill(GBC.BOTH).setWeight(100, 100));

        JPanel buttonPanel = new JPanel();
        add(buttonPanel, new GBC(0, 5, 2, 1));

        JButton sendButton = new JButton("Send");
        buttonPanel.add(sendButton);
        sendButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                new SwingWorker<Void, Void>() {
                    protected Void doInBackground() throws Exception {
                        comm.setText("");
                        sendMail();
                        return null;
                    }
                }.execute();
            }
        });
    }

    /**
     * Sends the mail message that has been authored in the GUI.
     */
    public void sendMail() {
        try {
            Socket s = new Socket(smtpServer.getText(), 25);

            InputStream inStream = s.getInputStream();
            OutputStream outStream = s.getOutputStream();

            in = new Scanner(inStream);
            out = new PrintWriter(outStream, true /* autoFlush */);

            String hostName = InetAddress.getLocalHost().getHostName();

            receive();
            send("HELO " + hostName);
            receive();
            send("MAIL FROM: <" + from.getText() + ">");
            receive();
            send("RCPT TO: <" + to.getText() + ">");
            receive();
            send("DATA");
            receive();
            send(message.getText());
            send(".");
            receive();
            s.close();
        } catch (IOException e) {
            comm.append("Error: " + e);
        }
    }

    /**
     * Sends a string to the socket and echoes it in the comm text area.
     * @param s the string to send.
     */
    public void send(String s) throws IOException {
        comm.append(s);
        comm.append("\n");
        out.print(s.replaceAll("\n", "\r\n"));
        out.print("\r\n");
        out.flush();
    }

    /**
     * Receives a string from the socket and displays it in the comm text area.
     */
    public void receive() throws IOException {
        String line = in.nextLine();
        comm.append(line);
        comm.append("\n");
    }

    private Scanner in;
    private PrintWriter out;
    private JTextField from;
    private JTextField to;
    private JTextField smtpServer;
    private JTextArea message;
    private JTextArea comm;

    public static final int DEFAULT_WIDTH = 300;
    public static final int DEFAULT_HEIGHT = 300;
}

/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
GBC - A convenience class to tame the GridBagLayout
    
Copyright (C) 2002 Cay S. Horstmann (http://horstmann.com)
    
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/**
This class simplifies the use of the GridBagConstraints
class.
*/
class GBC extends GridBagConstraints {
    /**
       Constructs a GBC with a given gridx and gridy position and
       all other grid bag constraint values set to the default.
       @param gridx the gridx position
       @param gridy the gridy position
    */
    public GBC(int gridx, int gridy) {
        this.gridx = gridx;
        this.gridy = gridy;
    }

    /**
       Constructs a GBC with given gridx, gridy, gridwidth, gridheight
       and all other grid bag constraint values set to the default.
       @param gridx the gridx position
       @param gridy the gridy position
       @param gridwidth the cell span in x-direction
       @param gridheight the cell span in y-direction
    */
    public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
        this.gridx = gridx;
        this.gridy = gridy;
        this.gridwidth = gridwidth;
        this.gridheight = gridheight;
    }

    /**
       Sets the anchor.
       @param anchor the anchor value
       @return this object for further modification
    */
    public GBC setAnchor(int anchor) {
        this.anchor = anchor;
        return this;
    }

    /**
       Sets the fill direction.
       @param fill the fill direction
       @return this object for further modification
    */
    public GBC setFill(int fill) {
        this.fill = fill;
        return this;
    }

    /**
       Sets the cell weights.
       @param weightx the cell weight in x-direction
       @param weighty the cell weight in y-direction
       @return this object for further modification
    */
    public GBC setWeight(double weightx, double weighty) {
        this.weightx = weightx;
        this.weighty = weighty;
        return this;
    }

    /**
       Sets the insets of this cell.
       @param distance the spacing to use in all directions
       @return this object for further modification
    */
    public GBC setInsets(int distance) {
        this.insets = new Insets(distance, distance, distance, distance);
        return this;
    }

    /**
       Sets the insets of this cell.
       @param top the spacing to use on top
       @param left the spacing to use to the left
       @param bottom the spacing to use on the bottom
       @param right the spacing to use to the right
       @return this object for further modification
    */
    public GBC setInsets(int top, int left, int bottom, int right) {
        this.insets = new Insets(top, left, bottom, right);
        return this;
    }

    /**
       Sets the internal padding
       @param ipadx the internal padding in x-direction
       @param ipady the internal padding in y-direction
       @return this object for further modification
    */
    public GBC setIpad(int ipadx, int ipady) {
        this.ipadx = ipadx;
        this.ipady = ipady;
        return this;
    }
}