Java - Concurrencia y Swing

/*

 * CapaPresentacioX2U1.java

 *

 * Created on 01-ago-2011, 22:04:42

 */

package xat2users;

import java.io.* ;

import java.util.concurrent.TimeUnit;

import javax.swing.* ;

/**

 *

 * @author David

 */

public class CapaPresentacioX2U1 extends JFrame {

    public PipedReader pr;

    public PipedWriter pw;

    public final Boolean mutex = false;

    public Boolean fi = false;

    /** Creates new form CapaPresentacioX2U1 */

    public CapaPresentacioX2U1(PipedReader prSocket, PipedWriter pwSocket, boolean mode) {

        initComponents();

        Emissor1 emissor = null;

        Receptor1 receptor = null;

        pr = new PipedReader(); // pipe de 'receptor' a CP.

        pw = new PipedWriter(); // pipe de CP a 'emissor'.

        // L'aplicació té dues finestres independents, i cadascuna 

        // genera dos fluxes, un emissor i un receptor, que s'associen 

        // a les pipes que passem com a paràmetres al constructor

        // de la classe.

        if (mode) {

            // En aquest cas, 'emissor' escriu a la pipe 'pwSocket'

            // i 'receptor' llegeix de la pipe 'prSocket'.

            emissor = new Emissor1(pwSocket, pw, fi);

            receptor = new Receptor1(prSocket, pr, fi, mutex);

            setTitle("Finestra 1");

        }

        else {

            // En l'altre cas possible, 'emissor' escriu a la pipe 'prSocket'

            // i 'receptor' llegeix de la pipe 'pwSocket'.

            try {

                emissor = new Emissor1(new PipedWriter(prSocket), pw, fi) ;

                receptor = new Receptor1(new PipedReader(pwSocket), pr, fi, mutex);

            }

            catch (IOException e) {

                System.err.println("Error en connectar pipes.");

                System.exit(1);

            }

            setTitle("Finestra 2");

        }

        // creem els threads:

        Thread t1 = new Thread(emissor);

        Thread t2 = new Thread(receptor);

        // iniciem els threads:

        t1.start();

        t2.start();

    }

    private void espera_activa_pipe_Receptor() {

        Transmissor tr = new Transmissor(); // creem un objecte

                // Transmissor per a usar la seva funció 'llegir'.

        while (!fi) {

            boolean exit = false;

            String s = null;

            while ((!exit) && (!fi)) {

                s = tr.llegir(pr);

                try {

                    if (s.equals("")) TimeUnit.MILLISECONDS.sleep(100);

                    else exit = true;

                }

                catch (InterruptedException e) {

                    System.err.println("Thread despertat mentre dormia.");

                }

            }

            if (exit) {

                synchronized(mutex) {

                    jTextArea1.append(s + "\n");

                }

            }

        }

    }

    /** This method is called from within the constructor to

     * initialize the form.

     * WARNING: Do NOT modify this code. The content of this method is

     * always regenerated by the Form Editor.

     */

    @SuppressWarnings("unchecked")

    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          

    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();

        jTextArea1 = new javax.swing.JTextArea();

        jTextField1 = new javax.swing.JTextField();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        addWindowListener(new java.awt.event.WindowAdapter() {

            public void windowClosing(java.awt.event.WindowEvent evt) {

                formWindowClosing(evt);

            }

        });

        jTextArea1.setColumns(20);

        jTextArea1.setRows(5);

        jScrollPane1.setViewportView(jTextArea1);

        jTextField1.setText("jTextField1");

        jTextField1.addActionListener(new java.awt.event.ActionListener() {

            public void actionPerformed(java.awt.event.ActionEvent evt) {

                jTextField1ActionPerformed(evt);

            }

        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());

        getContentPane().setLayout(layout);

        layout.setHorizontalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()

                .addContainerGap()

                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)

                    .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE)

                    .addComponent(jTextField1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE))

                .addContainerGap())

        );

        layout.setVerticalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()

                .addContainerGap()

                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 225, Short.MAX_VALUE)

                .addGap(18, 18, 18)

                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)

                .addGap(26, 26, 26))

        );

        pack();

    }// </editor-fold>                        

    private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {

        String s = jTextField1.getText(); // agafem el text del camp de text.

        if (!s.equals("")) {  // si el text no és buit el posem a l'historial.

            synchronized(mutex) {

                jTextArea1.append(s + "\n");  // posem el text a l'historial.

                    // el proper text anirà a la línia següent de l'historial..

                try {

                    pw.write(s); // enviem text a l'emissor.

                }

                catch (IOException e) {

                    System.err.println("Error en escriure a pipe.");

                }

            }

        }

    }

    private void formWindowClosing(java.awt.event.WindowEvent evt) {

        fi = true;

        System.exit(0);

    }

    /**

    * @param args the command line arguments

    */

    public static void main(String args[]) {

        final PipedReader prSocket = new PipedReader();

        final PipedWriter pwSocket = new PipedWriter();

        // Primera finestra:

        SwingUtilities.invokeLater(new Runnable() {

            public void run() {

                CapaPresentacioX2U1 cp = new CapaPresentacioX2U1(prSocket, pwSocket, false);

                cp.setVisible(true);

                cp.espera_activa_pipe_Receptor();

            }

        });

        // Segona finestra:

        SwingUtilities.invokeLater(new Runnable() {

            public void run() {

                CapaPresentacioX2U1 cp = new CapaPresentacioX2U1(prSocket, pwSocket, true);

                cp.setVisible(true);

                cp.espera_activa_pipe_Receptor();

            }

        });

    }

    // Variables declaration - do not modify                     

    private javax.swing.JScrollPane jScrollPane1;

    private javax.swing.JTextArea jTextArea1;

    private javax.swing.JTextField jTextField1;

    // End of variables declaration                   

}

/****************************************

 * $(name).java To change this template, choose Tools | Templates

 * $(name).java and open the template in the editor.

 **************************************/

package xat2users;

import java.io.* ;

/**

 *

 * @author David

 */

public class Emissor1 extends Transmissor implements Runnable {

    private Boolean fi;

    private PipedWriter pwSocket;  // simulador de socket.

    private PipedReader pr;

    /* Paràmetres:

     * pwSocket: pipe d'escriptura que simula socket de sortida.

     * pw : pipe d'escriptura que connecta amb la capa de presentació

     *      (llegirem d'ella per a aconseguir el missatge a enviar pel

     *      socket).

    */

    public Emissor1 (PipedWriter pwSocket, PipedWriter pw, Boolean fi) {

        this.pwSocket = pwSocket;

        this.fi = fi;

        try {

            pr = new PipedReader(pw); // 'pr' llegirà de 'pw'.

        }

        catch (IOException e) {

            System.err.println("Error en connectar pipe.");

            fi = true;

            System.exit(1);

        }

    }

    public void run () {

        while (!fi) {

            String s = llegir(pr);  // 'llegir' està definida a Transmissor.

            try {

                pwSocket.write(s);

            }

            catch (IOException e) {

                System.err.println("Error en escriure a la pipe.");

            }

        }

    }

}

/****************************************

 * $(name).java To change this template, choose Tools | Templates

 * $(name).java and open the template in the editor.

 **************************************/

package xat2users;

import java.io.* ;

import java.util.concurrent.TimeUnit;

/**

 *

 * @author David

 */

// Heretem de Transmissor per a heretar el mètode 'llegir', que s'usa

// tant a Emissor com a Receptor.

// Heretem de Runnable per a poder fer un thread.

class Receptor1 extends Transmissor implements Runnable {

    private PipedReader prSocket;  // Simula un socket.

    private PipedReader pr;

    private PipedWriter pw;

    private Boolean fi;

    private final Boolean mutex;

    /* Paràmetres:

     * prSocket: pipe de lectura que simula socket de entrada.

     * pr : pipe de lectura que connecta amb la capa de presentació

     *      (per a escriure a l'àrea de text d'historial de missatges).

    */

    public Receptor1 (PipedReader prSocket, PipedReader pr, Boolean fi, Boolean mutex) {

        super();

        this.prSocket = prSocket;

        this.fi = fi;

        this.mutex = mutex;

        try {

            pw = new PipedWriter(pr);

        }

        catch (IOException e) {

            System.err.println("Error en connectar pipe.");

            fi = true;  // per a què acabin la resta de threads.

            System.exit(1);

        }

    }

    public void run () {

        while (!fi) {

            String s = llegir_socket_fictici();

            try {

                synchronized(mutex) {

                    pw.write(s);

                }

            }

            catch (IOException e) {

                System.err.println("Error en escriure a pipe.");

            }

        }

    }

    private String llegir_socket_fictici( ) {

        String s = null;

        boolean exit = false;

        while ((!exit) && (!fi)) {

            s = llegir(prSocket);  // 'llegir' està definida a Transmissor.

            try {

                if (s.equals("")) TimeUnit.MILLISECONDS.sleep(100);

                else exit = true;

            }

            catch (InterruptedException e) {

                System.err.println("Thread despertat mentre dormia.");

            }

        }

        return s;

    }

}

/*

 * To change this template, choose Tools | Templates

 * and open the template in the editor.

 */

package xat2users;

import java.io.* ;

/**

 *

 * @author David

 */

public class Transmissor {

    String llegir (PipedReader pr) {

        String s = "";

        boolean fi_pipe = false;

        boolean fi_linia = false;

        while ((!fi_pipe) && (!fi_linia)) {

            try {

                int b = pr.read();

                if ( b == -1) fi_pipe = true;

                else {

                    char ch = (char) b;

                    if ((ch == '\n') || (ch == '\r')) fi_linia = true;

                    else s = s + ch;

                }

            }

            catch (IOException e) {

                System.err.println("Error en llegir de pipe.");

            }

        }

        return s;

    }

}