Cours sur l'utilisation du langage Java pour le développement de systèmes embarqués

DataInput
DataOutput

ByteArrayInputStream ByteArrayOutputStream
DataInputStream DataOutputStream
InputStream InputStreamReader
OutputStream OutputStreamWriter
PrintStream
Reader Writer

EOFException
InterruptedIOException
IOException
UnsupportedEncodingException
UTFDataFormatException

Runnable

oolean Byte Character Class Double Float
Integer Long Math Object Runtime Short
String StringBuffer System Thread Throwable

Exception ArithmeticException ArrayIndexOutOfBoundsException
 
ArrayStoreException ClassCastException ClassNotFoundException
 
IllegalAccessException IllegalArgumentException
 
IllegalMonitorStateException IllegalThreadStateException
 
IndexOutOfBoundsException InstantiationException
 
...

Error NoClassDefFoundError OutOfMemoryError VirtualMachineError

Reference
WeakReference

public WeakReference(Object ref)
public Object get(); // Returns this reference object's referent
public void clear(); // Clears this reference object.

Enumeration

Calendar
Date
Hashtable
Random
Stack
TimeZone
Vector

EmptyStackException
NoSuchElementException

Connection
ContentConnection
Datagram
DatagramConnection
InputConnection
OutputConnection
StreamConnection
StreamConnectionNotifier

Connector

ConnectionNotFoundException

java.lang.util: +Random +Timer +TimerTask ;
javax.microedition.io: +réseau: sockets, udp, série, push ;
javax.microedition.lcdui: interface graphique ;
javax.microedition.lcdui.game: jeux (sprites, layers, canvas) ;
javax.microedition.media: audio (control, player) ;
javax.microedition.media.control: contrôle du son ;
javax.microedition.midlet: interface avec l'application, cycle de vie ;
javax.microedition.pki: certificats, authentification ;
javax.microedition.rms: gestion des données persistantes.

void getViaStreamConnection(String url) throws IOException {
    StreamConnection c = null;
    InputStream s = null;
    try {
        c = (StreamConnection)Connector.open(url);
        s = c.openInputStream();
        int ch;
        while ((ch = s.read()) != -1) {
            ...
        }
    } finally {
        if (s != null)
            s.close();
        if (c != null)
            c.close();
    }
}

void getViaContentConnection(String url) throws IOException {
     ContentConnection c = null;
     DataInputStream dis = null;
     try {
         c = (ContentConnection)Connector.open(url);
         int len = (int)c.getLength();
         dis = c.openDataInputStream();
         if (len > 0) {
             byte[] data = new byte[len];
             dis.readFully(data);
         } else {
             int ch;
             while ((ch = dis.read()) != -1) {
                 ...
             }
         }
     } finally {
         if (dis != null) dis.close();
         if (c != null) c.close();
}}

void getViaHttpConnection(String url) throws IOException {
     HttpConnection c = null; InputStream is = null;
     int rc;
     try { c = (HttpConnection)Connector.open(url);
           rc = c.getResponseCode();
           if (rc != HttpConnection.HTTP_OK) {
               throw new IOException("HTTP response code: " + rc);
           }
           is = c.openInputStream();
           // Get the ContentType
           String type = c.getType();
           // Get the length and process the data
           int len = (int)c.getLength();
           if (len > 0) {
               int actual = 0; int bytesread = 0 ;
               byte[] data = new byte[len];
               while ((bytesread != len) && (actual != -1)) {
                  actual = is.read(data, bytesread, len - bytesread);
                  bytesread += actual;
               } else {
               int ch;
               while ((ch = is.read()) != -1) {
                   ...

SocketConnection sc = (SocketConnection)
                       Connector.open("socket://host.com:79");
sc.setSocketOption(SocketConnection.LINGER, 5);
InputStream is = sc.openInputStream();
OutputStream os = sc.openOutputStream();
 
os.write("\r\n".getBytes());
int ch = 0;
while(ch != -1) {
    ch = is.read();
}
 
is.close();
os.close();
sc.close();

SecureConnection sc = (SecureConnection)
                      Connector.open("ssl://host.com:79");
SecurityInfo info = sc.getSecurityInfo();
boolean isTLS = (info.getProtocolName().equals("TLS"));
 
sc.setSocketOption(SocketConnection.LINGER, 5);
 
InputStream is = sc.openInputStream();
OutputStream os = sc.openOutputStream();
os.write("\r\n".getBytes());
int ch = 0;
while(ch != -1) {
    ch = is.read();
}
is.close();
os.close();
sc.close();

Display display = Display.getDisplay(this);
Form f = new Form("StringItem");
f.append(new StringItem("Label1", "Text1"));
f.append(new StringItem("Label2", "Text."));
display.setCurrent(f);

Display display = Display.getDisplay(this);
List L = new List(...);
display.setCurrent(L);

// Dans la classe Canvas:
public final void repaint();
protected void keyPressed(int keyCode);
if (keyCode > 0)
   char ch = (char)keyCode;
 
// Dans la classe Graphics
public void drawString(String text, int x, int y, int anchor);
void drawArc(int x, int y, int width, int height,
             int startAngle, int arcAngle)
g.drawString(str, x, y, TOP|LEFT);
g.fillRect(x, y, w, h); // 1
g.drawRect(x, y, w, h); // 2

Command infoCommand = new Command("Info", Command.SCREEN, 2);
Command buyCommand = new Command("Buy", Command.SCREEN, 2);

Form form = new Form("Your Details");
...
form.addCommand(new Command("EXIT", Command.EXIT, 2));
form.addCommand(new Command("HELP", Command.HELP, 2));
form.addCommand(new Command("OK", Command.OK, 1));

try {
    recordStore = RecordStore.openRecordStore("scores", true);
} catch ...
int recId; // returned by addRecord but not used
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream outputStream = new DataOutputStream(baos);
try {
    // Push the score into a byte array.
    outputStream.writeInt(score);
    // Then push the player name.
    outputStream.writeUTF(playerName);
 } catch ...
 // Extract the byte array
 byte[] b = baos.toByteArray();
 try {
 recId = recordStore.addRecord(b, 0, b.length);
 } catch ...

public static RecordStore openRecordStore(String recordStoreName,
                                       boolean createIfNecessary,
                                       int authmode,
                                       boolean writable)

public void setMode(int authmode, boolean writable)

public class BasicApplet extends java.applet.Applet {
  public BasicApplet(){
       // constructor - don't do much here
  }
  public void init(){
       // applet context is ready, perform all one-time
       // initialization here
  }
  public void start(){
       // the applet is being displayed
  }
  public void stop(){
       // the applet is being hidden
}
  public void destroy(){
       // free up all resources
  }
}

<applet code="BasicApplet.class"
      width="300" height="200">
</applet>

import javax.microedition.midlet.*;
public class BasicMIDlet extends MIDlet {
  public BasicMIDlet(){
       // constructor - don't do much here
}
protected void destroyApp( boolean unconditional )
          throws MIDletStateChangeException {
       // called when the system destroys the MIDlet
}
protected void pauseApp(){
       // called when the system pauses the MIDlet
}
protected void startApp() throws MIDletStateChangeException {
       // called when the system activates the MIDlet
}}

Canvas canvas = new Canvas() {
 
exit = new Command("Exit", Command.STOP, 1);
canvas.addCommand(exit);
   canvas.setCommandListener(new CommandListener() {
     public void commandAction(Command c, Displayable d) {
       if(c == exit) {
          notifyDestroyed();
       } else {
         System.out.println("Saw the command: "+c);
       }
     }
});

public void startApp () {
    display = Display.getDisplay(this);
 
    // anonymous class
    Canvas canvas = new Canvas() {
 
      public void paint(Graphics g) { }
 
      protected void keyPressed(int keyCode) {
        if (keyCode > 0) {
          System.out.println("keyPressed "
             + ((char)keyCode));
        } else {
          System.out.println("keyPressed action "
             + getGameAction(keyCode));
        }
      }
    }
}

public class Hello extends MIDlet implements CommandListener {
private Display display;
private List mainMenu;
 
protected void startApp() throws MIDletStateChangeException {
 
  display = Display.getDisplay(this);
  String[] items = {"Gauge", "Appel téléphonique !", "Sortir"};
  mainMenu = new List("Main", Choice.IMPLICIT, items, null);
 
  // Je suis mon propre écouteur
  mainMenu.setCommandListener(this);
 
  // J'affiche
  display.setCurrent(mainMenu);
}
 
 
public void commandAction(Command c, Displayable d) {
  System.out.println("" + mainMenu.getSelectedIndex());
  if (mainMenu.getSelectedIndex() == 0)
     display.setCurrent(form);
  if (mainMenu.getSelectedIndex() == 1)
     this.notifyPaused();
  if (mainMenu.getSelectedIndex() == 2)
     this.notifyDestroyed();
}}

var result;
 
function run(args : String[]) {
 
  // Convert Strings to Integers
  def numOne = java.lang.Integer.parseInt(args[0]);
  def numTwo = java.lang.Integer.parseInt(args[1]);
 
  // Invoke Functions
  add(numOne,numTwo);
 
}
 
function add(argOne: Integer, argTwo: Integer) {
  result = argOne + argTwo;
  println("{argOne} + {argTwo} = {result}");
}

javafx calculator 100 50

Address {
  street: "1 Main Street";
  city: "Santa Clara";
  state: "CA";
  zip: "95050";
}

// LICENCE: cf [L1]
public class Address {
  public var street: String;
  public var city: String;
  public var state: String;
  public var zip: String;
}

var customer = Customer {
   firstName: "John";
   lastName: "Doe";
   address: Address {
        street: "1 Main Street";
        city: "Santa Clara";
        state: "CA";
        zip: "95050";
}}
customer.printName();
 
public class Customer {
   public var firstName: String;
   public var lastName: String;
   public var address: Address;
  public function printName() {
      println("Name: {firstName} {lastName}");
}

def name = 'Joe';
var s = "Hello {name}"; // s = 'Hello Joe'
def answer = true;
var s = "The answer is {if (answer) "Yes" else "No"}";
def one = "This example ";
def two = "joins two strings.";
def three = "{one}{two}"; // join string one and string two
println(three); // 'This example joins two strings.'

def numOne = 1.0; // compiler will infer Number
def numTwo = 1; // compiler will infer Integer
def numOne2 : Number = 1.0;
def numTwo2 : Integer = 1;
var isAsleep = true;
if (isAsleep) {
   wakeUp();
}

function printMe(arg1: Address) : Void {
   if (arg1 != null)
           println("I don't return anything!");
}

var myFunc : function(:Object,:Integer):String;
myFunc = function(obj : Object, k : Integer)
         { "Here is the Object: {obj}, and the Integer: {k}" }
println(myFunc(null, 1234));
// Prints: Here is the Object: null, and the Integer: 1234

def weekDays = ["Lundi", "Mardi", "Samedi", "Dimanche"];
def days = [weekDays, "Sat","Sun"];
def samedidimanche = days[2..3];
def nums = [1..100];
def numsGreaterThanTwo = nums[n | n > 2];
var nums = [1..10 step 2];
 
var weekDays = ["Lundi","Mardi","Mercredi","Jeudi", "Vendredi"];
var days = [weekDays, ["Samedi","Dimanche"]];
def tmp = days[3..4];
println(tmp); //retourne : [ Jeudi, Vendredi ]

insert "Tue" into days;
insert "Thu" before days[2];
insert "wed" after days[1];
nums = reverse nums;

var days = ["Mon","Tue","Wed","Thu","Fri","Sat","Sun"];
 
for (day in days) {
   println(day);
}

try {
   foo();
} catch (e: Exception) {
   println("{e.getMessage()} (but we caught it)");
} finally {
   println("We are now in the finally expression...");
}

def x = bind if (condExpr) expr1 else expr2;

def newSeq = bind for (elem in seq) expr;

var max = 3;
function square(x : Integer) : Integer { x*x }
def values = bind for (x in [0..max]) square(x); 1
println(values); // Output: [ 0, 1, 4, 9 ]
max = 5; // Output: [ 0, 1, 4, 9, 16, 25 ]

class Point {
  var x : Number;
  var y : Number;}
 
var scale = 1.0;
function makePoint(x0 : Number, y0 : Number) : Point {
  Point {
    x: x0 * scale
    y: y0 * scale
}}
 
var myX = 3.0; var myY = 3.0;
def pt = bind makePoint(myX, myY);
println(pt.x); // Output: 3.0
myX = 10.0; println(pt.x); // Output: 10.0
scale = 2.0; println(pt.x); // Output: 10.0 (20.0 si bound)
 
// Mise à jour de pt.x lorsque scale = 2.0 si makePoint est:
bound function makePoint(x0 : Number, y0 : Number) : Point
{ ...

def pt = bind Point {
 x: myX
 y: myY
}

def pt = bind Point {
 x: bind myX
 y: bind myY
}

var count = 0;
def images = for(i in [0..9]){Image {url: "{__DIR__}{i}.png"};}
var currImg = images[count];
 
Stage {
    scene: Scene {
        content: ImageView {
            image: bind currImg
            onMouseClicked:
                function(e: MouseEvent) {
                    println("Click number {++count} ...");
                    currImg = images[count];
} } } }

var z = bind x with inverse; // Et non pas:
var maVariable = bind autreVariable;
var autreVariable = bind maVariable; // qui retourne :
/home/jf/workspaceJavaME/JavaFX Project/src/gstutorial/Main.fx:22: This
is the cyclic reference to maVariable that prevents type inference.

class Point {
  var x : Number;
  var y : Number;
  override function toString() : String { "Point({x},{y})" }
}
def pt = Point {
   x: 3.0
   y: 5.0
}
def projectionOnX = Point {
   x: bind pt.x with inverse
   y: 0.0
}

// Inside file tutorial/one.fx
package tutorial;
public def someMessage = "This is a public script variable, in one.fx";
public class one {
     public var message = "Hello from class one!";
     public function printMessage() {
          println("{message} (in function printMessage)");
     }
}
 
// Inside file two.fx
import tutorial.one;
println(one.someMessage);
var o = one{};
println(o.message);
o.printMessage();

// Inside file tutorial/one.fx
package tutorial;
public class one {
     protected var message = "Hello!";
}
 
// Inside file two.fx
import tutorial.one;
class two extends one {
     function printMessage() {
          println("Class two says {message}");
     }
};
var t = two{};
t.printMessage();

// Inside file tutorial/one.fx
package tutorial;
public-read var x = 1;
 
// Inside tutorial/two.fx
package tutorial;
println(one.x);
one.x = 2; // interdit

tutorial/two.fx:3: x has script only (default) write access in tutorial.one
one.x = 2;
^
1 error

package public-read var x = 1;

// Inside file tutorial/one.fx
package tutorial;
public class one {
     public-init var message;
}
 
// Inside file two.fx
import tutorial.one;
var o = one {
     message: "Initialized this variable from a different package!"
}
println(o.message);

public class JavaFXApplication1 extends Application {
 
 @Override
 public void start(Stage primaryStage) {
 
     StackPane root = new StackPane();
     Label l = new Label("Hello World!");
     root.getChildren().add(l);
     l.translateXProperty().set(25.0);
     l.translateYProperty().set(25.0);
 
     Scene scene = new Scene(root, 300, 250);
 
     primaryStage.setTitle("Hello World!");
     primaryStage.setScene(scene);
     primaryStage.show();
 }
 public static void main(String[] args) {
     launch(args);
 }
}

content: [
        Circle {
            centerX: 50 centerY: 50 radius: 50
            stroke: Color.YELLOW
            fill: Color.WHITE
        },
        Text {
            transforms: Transform.rotate(33, 10, 100)
                content: "Duke"
        },
            ImageView {
            image: Image {url: "{__DIR__}dukewave.png"}
} ]

* @see http://www.java2s.com/Code/Java/JavaFX/UsingRadialGradienttocreateaBall.htm
    StackPane root = new StackPane();
    Circle c = new Circle(50,50,50);
    c.strokeProperty().setValue(Color.YELLOW);
    c.fillProperty().setValue(Color.WHITE);
    Text t = new Text("Duke");
    t.rotateProperty().setValue(33);
    t.translateXProperty().setValue(20);t.translateYProperty().setValue(-30);
    Image i = new Image("file:/home/jf/ensib/cours/java_embarque/images/ensi.png");
    ImageView iv1 = new ImageView();
    iv1.setFitWidth(90); iv1.setPreserveRatio(true);
    iv1.setImage(i);
 
    root.getChildren().add(c); root.getChildren().add(t); root.getChildren().add(iv1);
 
    Scene scene = new Scene(root, 300, 250);
    primaryStage.setTitle("Circle");
    primaryStage.setScene(scene);
    primaryStage.show();

def slider = Slider {
    min: 0 max: 60 value : 0
    translateX: 10 translateY: 110 }
content: [ slider, Circle {
       centerX: bind slider.value + 50 centerY : 60 radius: 50
       stroke: Color.YELLOW
       fill: RadialGradient {
           centerX: 50 centerY: 60 radius: 50 focusX: 50 focusY: 30
           proportional: false
           stops: [ Stop {offset: 0 color: Color.RED},
                    Stop {offset: 1 color: Color.WHITE} ]
}} ] // End of RadialGradient and Circle

// @see thanks to http://www.asgteach.com/blog/?p=272
public void start(Stage primaryStage) {
    StackPane root = new StackPane();
    final Slider s = new Slider(0,60,0);
    s.translateXProperty().setValue(10);
    s.translateYProperty().setValue(60);
    Circle c = new Circle(50,60,50);
    c.strokeProperty().setValue(Color.YELLOW);
    RadialGradient radial = new RadialGradient(270, 50, 50, 60, 50, false, CycleMethod.NO_CYCLE,
            new Stop(0, Color.RED),
            new Stop(1, Color.WHITE));
    c.setFill(radial);
 
    DoubleBinding doubleBinding = new DoubleBinding() {
        { // Constructor here
          super.bind(s.valueProperty());
        }
        protected double computeValue() {
             return s.valueProperty().doubleValue();
    }};
    c.centerXProperty().bind(doubleBinding);
    root.getChildren().add(c); root.getChildren().add(s);
    Scene scene = new Scene(root, 300, 250);
    primaryStage.setTitle("Circle"); primaryStage.setScene(scene);
     primaryStage.show();
}

content:
     HBox{
        spacing: 20
        content:[
           VBox{ spacing: 10
                 content: choices
           }
           HBox{ spacing: 15 content: lights nodeVPos: VPos.CENTER}
         ]
      }//HBox

var x: Number;
 
Timeline {
  keyFrames: [
          at (0s) {x => 0.0},
          at (4s) {x => 158.0 tween Interpolator.LINEAR}
  ]
}.play();
 
Path{
...
translateX: bind x
...
}

def playNormal = Image { url: "{__DIR__}play_onMouseExited.png"};
def playHover = Image { url: "{__DIR__}play_onMouseEntered.png"}; ...
var mode = true; //true for the Play mode, false for the Stop mode
var X: Number; var Y: Number;
Stage {
 title: "Play Button"
 scene: Scene {
     fill: Color.WHITE
     width: 300
     height: 240
     content: Group {
         content: [ button ]
         onMouseEntered: function(event) {
              image = if (mode){ playHover; } else { stopHover }
         }
         onMousePressed: function(event) {
              X = event.sceneX - event.node.translateX;
              Y = event.sceneY - event.node.translateY;
              image = if (mode){ playPressed; } else { stopPressed; }
         }
         onMouseDragged: function(event) {
             if (event.sceneX - X <0) {
                 event.node.translateX = 0;
             } else { if (event.sceneX - X > 300 - image.width){
                 event.node.translateX = 300 - image.width;
             } else {
                 event.node.translateX = event.sceneX - X;
             }
... }}}

public class HitServlet extends HttpServlet {
private int mCount;
 
public void doGet(HttpServletRequest request,
    HttpServletResponse response)
    throws ServletException, IOException {
  String message = "Hits: " + ++mCount;
 
  response.setContentType("text/plain");
  response.setContentLength(message.length());
  PrintWriter out = response.getWriter();
  out.println(message);
}
}

HttpConnection hc = null;
 InputStream in = null;
 String url = getAppProperty("HitMIDlet.URL");
 try {
   hc = (HttpConnection)Connector.open(url);
   in = hc.openInputStream();
 
   int contentLength = (int)hc.getLength();
   byte[] raw = new byte[contentLength];
   int length = in.read(raw);
 
   in.close();
   hc.close();
 
   // Show the response to the user.
   String s = new String(raw, 0, length);
   ...

IMCServerConnection imcServerConnection = (IMCServerConnection)
  Connector.open("imc://:com.abc.sessionManager:1.0");
IMCConnection imcConnection = (IMCConnection)
  imcServerConnection.acceptAndOpen();
DataOutputStream dataOutputStream =
  imcConnection.openDataOutputStream();
 
// Now that the connection is open,
// send the login status.
dataOutputStream.writeUTF(loginStatus);
dataOutputStream.flush();
IMCConnection imcConnection = (IMCConnection)
  Connector.open("imc://:com.abc.sessionManager:1.0");
DataInputStream dataInputStream = imcConnection.openDataInputStream();
 
// Now that the connection is open,
// retrieve the log-in status.
loginStatus = dataInputStream.readUTF();

XmlPullParser xpp = new KXmlParser();
 
xpp.setInput( new StringReader ( "<foo>Hello World!</foo>" ) );
int eventType = xpp.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
 if(eventType == XmlPullParser.START_DOCUMENT) {
     System.out.println("Start document");
 } else if(eventType == XmlPullParser.END_DOCUMENT) {
     System.out.println("End document");
 } else if(eventType == XmlPullParser.START_TAG) {
     System.out.println("Start tag "+xpp.getName());
 } else if(eventType == XmlPullParser.END_TAG) {
     System.out.println("End tag "+xpp.getName());
 } else if(eventType == XmlPullParser.TEXT) {
     System.out.println("Text "+xpp.getText());
 }
 eventType = xpp.next();
}

<elements>
  <text>text1</text>
  <text>text2</text>
</elements>
 
parser.nextTag();
parser.require(XmlPullParser.START_TAG, null, "elements");
while(parser.nextTag() == XmlPullParser.START_TAG) {
  parser.require(XmlPullParser.START_TAG, null, "text");
  // handle element content
  System.out.println("text content: "+ parser.nextText());
  parser.require(XmlPullParser.END_TAG, null, "text");
}
 
parser.require(XmlPullParser.END_TAG, null, "elements");

class DataTypes {
  public String aString; // a string
  public String[] anArray; // an array
  public int anInteger; // an integer
//public double aDouble; // double not supported on CLDC 1.0
  public long aLong; // a long
  public boolean aBoolean; // a boolean
 
  public DataTypes(
          String aString,
          String[] anArray,
          int anInteger,
        //double aDouble, // Not supported on CLDC 1.0
          long aLong,
          boolean aBoolean) {
      this.aString = aString;
      this.anArray = anArray;
      this.anInteger = anInteger;
    //this.aDouble = aDouble; // Not supported on CLDC 1.0
      this.aLong = aLong;
      this.aBoolean = aBoolean;
}}

public String toJSON() {
  // Define an external an a nexted JSONObjects
  JSONObject outer = new JSONObject();
  JSONObject inner = new JSONObject();
  // Now generate the JSON output
  try {
      outer.put("datatypes", inner); // the outer object name
      inner.put("aString", aString); // a name/value pair
      JSONArray ja = new JSONArray();
      for (int i=0; i<anArray.length; i++) {
          ja.put(anArray[i]);
      }
      inner.put("anArray", ja); a name/value pair
      inner.put("anInteger", anInteger); a name/value pair
    //inner.put("aDouble", aDouble); // Not supported on CLDC 1.0
      inner.put("aLong", aLong); a name/value pair
      inner.put("aBoolean", aBoolean); a name/value pair
  } catch (JSONException ex) {
      // ...process exception
  }
  return outer.toString(); // return the JSON text
}

aString = null; anArray = null;
anInteger = 0;
aLong = 0; aBoolean = false;
 
try {
    JSONObject outer = new JSONObject(ji); // the outer objet
    if (outer != null) {
        // Get the inner object and parse out the data
        JSONObject inner = outer.getJSONObject("datatypes");
        if (inner != null) {
             // Parse the name/value pairs
             aString = inner.getString("aString");
             JSONArray ja = inner.getJSONArray("anArray");
        if (ja != null) {
            anArray = new String[ja.length()];
            for (int i=0; i<ja.length(); i++) {
                 anArray[i] = (String) ja.get(i);
        }}
        anInteger = inner.getInt("anInteger");
        aLong = inner.getLong("aLong");
        aBoolean = inner.getBoolean("aBoolean");

 // Create an initialize instance of DataTypes
DataTypes dt = new DataTypes(
  "C. Enrique Ortiz", // a String
  new String[] {"tech","mobile","web", "apps"}, // an Array
  15569, // an int
 //0.0, // a double, not supported on CLDC 1.0
   1234567890, // a long
   true); // a boolean
 // Covert object to JSON
String j = dt.toJSON();
System.out.println("*** toJSON: " + j);
 
 // Initialize object from JSON
System.out.println("*** fromJSON:");
dt.fromJSON(j);
 
 // Dump to console to see if it worked
dt.dump();