{"id":461,"date":"2007-12-03T00:00:00","date_gmt":"2007-12-02T16:00:00","guid":{"rendered":"http:\/\/www.strongd.net\/?p=461"},"modified":"2011-07-15T09:52:58","modified_gmt":"2011-07-15T01:52:58","slug":"timer-server","status":"publish","type":"post","link":"https:\/\/www.strongd.net\/?p=461","title":{"rendered":"Timer Server"},"content":{"rendered":"

import <\/STRONG><\/FONT>java.io.InterruptedIOException;<\/FONT>
import <\/B><\/FONT>javax.microedition.io.Connector;<\/FONT>
import <\/B><\/FONT>javax.microedition.io.Datagram;<\/FONT>
import <\/B><\/FONT>javax.microedition.io.DatagramConnection;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.Alert;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.AlertType;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.Command;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.CommandListener;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.Display;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.Displayable;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.Form;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.StringItem;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.TextField;<\/FONT>
import <\/B><\/FONT>javax.microedition.midlet.MIDlet;<\/FONT>
import <\/B><\/FONT>javax.microedition.midlet.MIDletStateChangeException;<\/FONT>
<\/FONT>
public class <\/B><\/FONT>TimeMIDlet <\/FONT>extends <\/B><\/FONT>MIDlet<\/FONT>
                    <\/FONT>implements <\/B><\/FONT>CommandListener, Runnable <\/FONT>{<\/FONT>
<\/FONT>
    <\/FONT>private <\/B><\/FONT>Display display;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Form addressForm;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Form connectForm;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Form displayForm;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Command backCommand;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Command exitCommand;<\/FONT>
    <\/FONT>private <\/B><\/FONT>Command okCommand;<\/FONT>
    <\/FONT>private <\/B><\/FONT>StringItem messageLabel;<\/FONT>
    <\/FONT>private <\/B><\/FONT>TextField serverName;<\/FONT>
<\/FONT>
    <\/FONT>protected <\/B><\/FONT>void <\/B><\/FONT>startApp<\/FONT>() <\/FONT>throws <\/B><\/FONT>MIDletStateChangeException <\/FONT>{<\/FONT>
        <\/FONT>if <\/B><\/FONT>(<\/FONT>display == <\/FONT>null<\/B><\/FONT>) {<\/FONT>
            <\/FONT>initialize<\/FONT>()<\/FONT>;<\/FONT>
            <\/FONT>display.setCurrent<\/FONT>(<\/FONT>addressForm<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>}<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>protected <\/B><\/FONT>void <\/B><\/FONT>pauseApp<\/FONT>() {<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>protected <\/B><\/FONT>void <\/B><\/FONT>destroyApp<\/FONT>(<\/FONT>boolean <\/B><\/FONT>unconditional<\/FONT>)<\/FONT>
                        <\/FONT>throws <\/B><\/FONT>MIDletStateChangeException <\/FONT>{<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>commandAction<\/FONT>(<\/FONT>Command cmd, Displayable d<\/FONT>) {<\/FONT>
        <\/FONT>if <\/B><\/FONT>(<\/FONT>cmd == okCommand<\/FONT>) {<\/FONT>
            <\/FONT>Thread t = <\/FONT>new <\/B><\/FONT>Thread<\/FONT>(<\/FONT>this<\/B><\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>t.start<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>} <\/FONT>else if <\/B><\/FONT>(<\/FONT>cmd == backCommand<\/FONT>) {<\/FONT>
            <\/FONT>display.setCurrent<\/FONT>(<\/FONT>addressForm<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>} <\/FONT>else if <\/B><\/FONT>(<\/FONT>cmd == exitCommand<\/FONT>) {<\/FONT>
            <\/FONT>try <\/B><\/FONT>{<\/FONT>
                <\/FONT>destroyApp<\/FONT>(<\/FONT>true<\/B><\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>} <\/FONT>catch <\/B><\/FONT>(<\/FONT>MIDletStateChangeException ex<\/FONT>) {<\/FONT>
            <\/FONT>}<\/FONT>
            <\/FONT>notifyDestroyed<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>}<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>run<\/FONT>() {<\/FONT>
        <\/FONT>DatagramConnection conn = <\/FONT>null<\/B><\/FONT>;<\/FONT>
        <\/FONT>display.setCurrent<\/FONT>(<\/FONT>connectForm<\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>try <\/B><\/FONT>{<\/FONT>
            <\/FONT>\/\/ Build the name string for the Connector open method<\/FONT>
            <\/FONT>String server = serverName.getString<\/FONT>()<\/FONT>;<\/FONT>
            <\/FONT>String name = <\/FONT>“datagram:\/\/” <\/FONT>+ server + <\/FONT>“:” <\/FONT>+ <\/FONT>13<\/FONT>;<\/FONT>
            <\/FONT>conn = <\/FONT>(<\/FONT>DatagramConnection<\/FONT>)<\/FONT>Connector.open<\/FONT>(<\/FONT>name,<\/FONT>
                                    <\/FONT>Connector.READ_WRITE, <\/FONT>false<\/B><\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
            <\/FONT>\/\/ Build and send an empty datagram<\/FONT>
            <\/FONT>Datagram dg = conn.newDatagram<\/FONT>(<\/FONT>10<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>dg.setData<\/FONT>(<\/FONT>“Hello”<\/FONT>.getBytes<\/FONT>()<\/FONT>, <\/FONT>0<\/FONT>, <\/FONT>5<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>conn.send<\/FONT>(<\/FONT>dg<\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
            <\/FONT>\/\/ Receive the reply<\/FONT>
            <\/FONT>Datagram rdg = conn.newDatagram<\/FONT>(<\/FONT>512<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>conn.receive<\/FONT>(<\/FONT>rdg<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>messageLabel.setText<\/FONT>(<\/FONT>new <\/B><\/FONT>String<\/FONT>(<\/FONT>rdg.getData<\/FONT>()<\/FONT>, <\/FONT>0<\/FONT>, rdg.getLength<\/FONT>()))<\/FONT>;<\/FONT>
            <\/FONT>display.setCurrent<\/FONT>(<\/FONT>displayForm<\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>} <\/FONT>catch <\/B><\/FONT>(<\/FONT>InterruptedIOException iex<\/FONT>) {<\/FONT>
            <\/FONT>display.callSerially<\/FONT>(<\/FONT>new <\/B><\/FONT>Runnable<\/FONT>() {<\/FONT>
                <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>run<\/FONT>() {<\/FONT>
                    <\/FONT>Alert alert = <\/FONT>new <\/B><\/FONT>Alert<\/FONT>(<\/FONT>“No Reply”<\/FONT>,<\/FONT>
                        <\/FONT>“No reply was received.\\n” <\/FONT>+<\/FONT>
                        <\/FONT>“Please check the server address and try again.”<\/FONT>, null,<\/FONT>
                        <\/FONT>AlertType.ERROR<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>alert.setTimeout<\/FONT>(<\/FONT>Alert.FOREVER<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>display.setCurrent<\/FONT>(<\/FONT>alert, addressForm<\/FONT>)<\/FONT>;<\/FONT>
                <\/FONT>}<\/FONT>
            <\/FONT>})<\/FONT>;<\/FONT>
            <\/FONT>return<\/B><\/FONT>;<\/FONT>
        <\/FONT>} <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception ex<\/FONT>) {<\/FONT>
            <\/FONT>display.callSerially<\/FONT>(<\/FONT>new <\/B><\/FONT>Runnable<\/FONT>() {<\/FONT>
                <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>run<\/FONT>() {<\/FONT>
                    <\/FONT>Alert alert = <\/FONT>new <\/B><\/FONT>Alert<\/FONT>(<\/FONT>“Invalid Address”<\/FONT>,<\/FONT>
                        <\/FONT>“The supplied address is invalid\\n” <\/FONT>+<\/FONT>
                        <\/FONT>“Please correct it and try again.”<\/FONT>, null,<\/FONT>
                        <\/FONT>AlertType.ERROR<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>alert.setTimeout<\/FONT>(<\/FONT>Alert.FOREVER<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>display.setCurrent<\/FONT>(<\/FONT>alert, addressForm<\/FONT>)<\/FONT>;<\/FONT>
                <\/FONT>}<\/FONT>
            <\/FONT>})<\/FONT>;<\/FONT>
            <\/FONT>return<\/B><\/FONT>;<\/FONT>
        <\/FONT>} <\/FONT>catch <\/B><\/FONT>(<\/FONT>Error err<\/FONT>) {<\/FONT>
            <\/FONT>System.out.println<\/FONT>(<\/FONT>err<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>err.printStackTrace<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>}<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>private <\/B><\/FONT>void <\/B><\/FONT>initialize<\/FONT>() {<\/FONT>
        <\/FONT>display = Display.getDisplay<\/FONT>(<\/FONT>this<\/B><\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>\/\/ Commands<\/FONT>
        <\/FONT>exitCommand = <\/FONT>new <\/B><\/FONT>Command<\/FONT>(<\/FONT>“Exit”<\/FONT>, Command.EXIT, <\/FONT>0<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>okCommand = <\/FONT>new <\/B><\/FONT>Command<\/FONT>(<\/FONT>“OK”<\/FONT>, Command.OK, <\/FONT>0<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>backCommand = <\/FONT>new <\/B><\/FONT>Command<\/FONT>(<\/FONT>“Back”<\/FONT>, Command.BACK, <\/FONT>0<\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>\/\/ The address form<\/FONT>
        <\/FONT>addressForm = <\/FONT>new <\/B><\/FONT>Form<\/FONT>(<\/FONT>“Network Time”<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>serverName = <\/FONT>new <\/B><\/FONT>TextField<\/FONT>(<\/FONT>“Time Server name:”<\/FONT>, <\/FONT>“tock.usno.navy.mil”<\/FONT>,<\/FONT>
                                            <\/FONT>256<\/FONT>, TextField.ANY<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>addressForm.append<\/FONT>(<\/FONT>serverName<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>addressForm.addCommand<\/FONT>(<\/FONT>okCommand<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>addressForm.addCommand<\/FONT>(<\/FONT>exitCommand<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>addressForm.setCommandListener<\/FONT>(<\/FONT>this<\/B><\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>\/\/ The connect form<\/FONT>
        <\/FONT>connectForm = <\/FONT>new <\/B><\/FONT>Form<\/FONT>(<\/FONT>“Sending”<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>messageLabel = <\/FONT>new <\/B><\/FONT>StringItem<\/FONT>(<\/FONT>null,<\/FONT>
                    <\/FONT>“Sending the datagram…\\nPlease wait.”<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>connectForm.append<\/FONT>(<\/FONT>messageLabel<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>connectForm.addCommand<\/FONT>(<\/FONT>backCommand<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>connectForm.setCommandListener<\/FONT>(<\/FONT>this<\/B><\/FONT>)<\/FONT>;<\/FONT>
<\/FONT>
        <\/FONT>\/\/ The display form<\/FONT>
        <\/FONT>displayForm = <\/FONT>new <\/B><\/FONT>Form<\/FONT>(<\/FONT>“Server Reply”<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>messageLabel = <\/FONT>new <\/B><\/FONT>StringItem<\/FONT>(<\/FONT>null, <\/FONT>null<\/B><\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>displayForm.append<\/FONT>(<\/FONT>messageLabel<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>displayForm.addCommand<\/FONT>(<\/FONT>backCommand<\/FONT>)<\/FONT>;<\/FONT>
        <\/FONT>displayForm.setCommandListener<\/FONT>(<\/FONT>this<\/B><\/FONT>)<\/FONT>;<\/FONT>
    <\/FONT>}<\/FONT>
}<\/FONT><\/FONT><\/DIV><\/p>\n","protected":false},"excerpt":{"rendered":"

import java.io.InterruptedIOException;import javax.microedition.io.Connector;import javax.microedition.io.Datagram;import javax.microedition.io.DatagramConnection;import javax.microedition.lcdui.Alert;import javax.microedition.lcdui.AlertType;import javax.microedition.lcdui.Command;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Display;import javax.microedition.lcdui.Displayable;import javax.microedition.lcdui.Form;import javax.microedition.lcdui.StringItem;import javax.microedition.lcdui.TextField;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class TimeMIDlet extends MIDlet                    implements CommandListener, Runnable {    private Display display;    private Form addressForm;    private Form connectForm;    private Form displayForm;    private Command backCommand;    private Command exitCommand;    private Command okCommand;    private StringItem messageLabel;    private TextField serverName;    protected void startApp() throws MIDletStateChangeException {        if (display == null) {            initialize();            display.setCurrent(addressForm);        }    }    protected void pauseApp() {    }    protected void destroyApp(boolean unconditional)                        throws MIDletStateChangeException {    }    public void commandAction(Command cmd, Displayable d) {        if (cmd == okCommand) {            Thread t = new Thread(this);            t.start();        } else if (cmd == backCommand) {            display.setCurrent(addressForm);        } else if (cmd == exitCommand) {            try {                destroyApp(true);            } catch (MIDletStateChangeException ex) {            }            notifyDestroyed();        }    }    public void run() {        DatagramConnection conn = null;        display.setCurrent(connectForm);        try {            \/\/ Build the name string for the Connector open method            String server = serverName.getString();            String name = “datagram:\/\/” + server + “:” + 13;            conn = (DatagramConnection)Connector.open(name,                                    Connector.READ_WRITE, false);            \/\/ Build and send an empty datagram            Datagram dg = conn.newDatagram(10);            dg.setData(“Hello”.getBytes(), 0, 5);            conn.send(dg);            \/\/ Receive the reply            Datagram rdg = conn.newDatagram(512);            conn.receive(rdg);            messageLabel.setText(new String(rdg.getData(), 0, rdg.getLength()));            display.setCurrent(displayForm);        } catch (InterruptedIOException iex) {            display.callSerially(new Runnable() {                public void run() {                    Alert alert = new Alert(“No Reply”,                        “No reply was received.\\n” +                        “Please check the server address and try again.”, null,                        AlertType.ERROR);                    alert.setTimeout(Alert.FOREVER);                    display.setCurrent(alert, addressForm);                }            });            return;        } catch (Exception ex) {            display.callSerially(new Runnable() {                public void run() {                    Alert alert = new Alert(“Invalid Address”,                        “The supplied address is invalid\\n” +                        “Please correct it and try again.”, null,                        AlertType.ERROR);                    alert.setTimeout(Alert.FOREVER);                    display.setCurrent(alert, addressForm);                }            });            return;        } catch (Error err) {            System.out.println(err);            err.printStackTrace();        }    }    private void initialize() {        display = Display.getDisplay(this);        \/\/ Commands        exitCommand = new Command(“Exit”, Command.EXIT, 0);        okCommand = new Command(“OK”, Command.OK, 0);        backCommand = new Command(“Back”, Command.BACK, 0);        \/\/ The address form        addressForm = new Form(“Network Time”);        serverName = new TextField(“Time Server name:”, “tock.usno.navy.mil”,                                            256, TextField.ANY);        addressForm.append(serverName);        addressForm.addCommand(okCommand);        addressForm.addCommand(exitCommand);        addressForm.setCommandListener(this);        \/\/ The connect form        connectForm = new Form(“Sending”);        messageLabel = new StringItem(null,                    “Sending the datagram…\\nPlease wait.”);        connectForm.append(messageLabel);        connectForm.addCommand(backCommand);        connectForm.setCommandListener(this);        \/\/ The display form        displayForm = new Form(“Server Reply”);        messageLabel = new StringItem(null, null);        displayForm.append(messageLabel);        displayForm.addCommand(backCommand);        displayForm.setCommandListener(this);    }}<\/p>\n","protected":false},"author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