Java/J2ME/Environment

Attributes MIDlet

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.StringItem;
import javax.microedition.midlet.MIDlet;
public class AttributesMIDlet extends MIDlet implements CommandListener {
  private Display display;
  protected boolean started;
  private Command exitCommand;
  protected void startApp() {
    if (!started) {
      display = Display.getDisplay(this);
      Canvas canvas = new DummyCanvas();
      Form form = new Form("Attributes");
      exitCommand = new Command("Exit", Command.EXIT, 0);
      form.addCommand(exitCommand);
      boolean isColor = display.isColor();
      form.append(new StringItem(isColor ? "Colors: " : "Grays: ", String.valueOf(display
          .numColors())));
      form.append(new StringItem("Width: ", String.valueOf(canvas.getWidth())));
      form.append(new StringItem("Height: ", String.valueOf(canvas.getHeight())));
      form.append(new StringItem("Pointer? ", String.valueOf(canvas.hasPointerEvents())));
      form.append(new StringItem("Motion? ", String.valueOf(canvas.hasPointerMotionEvents())));
      form.append(new StringItem("Repeat? ", String.valueOf(canvas.hasRepeatEvents())));
      form.append(new StringItem("Buffered? ", String.valueOf(canvas.isDoubleBuffered())));
      form.setCommandListener(this);
      display.setCurrent(form);
      started = true;
    }
  }
  protected void pauseApp() {
  }
  protected void destroyApp(boolean unconditional) {
  }
  public void commandAction(Command c, Displayable d) {
    if (c == exitCommand) {
      notifyDestroyed();
    }
  }
}
class DummyCanvas extends Canvas {
  protected void paint(Graphics g) {
  }
}

Check Color

// jad file
/*
MIDlet-Name: ColorCheck
MIDlet-Version: 1.0
MIDlet-Vendor: MyCompany
MIDlet-Jar-URL: ColorCheck.jar
MIDlet-1: ColorCheck, ColorCheck.png, ColorCheck
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
MIDlet-JAR-SIZE: 100
*/
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.TextBox;
import javax.microedition.midlet.MIDlet;
public class CheckColor extends MIDlet implements CommandListener {
  private Display display;
  private TextBox textbox = new TextBox("Check Colors", "", 17, 0);
  private Command exit = new Command("Exit", Command.SCREEN, 1);
  public CheckColor() {
    display = Display.getDisplay(this);
    String message = null;
    if (display.isColor()) {
      message = "Color display.";
    } else {
      message = "No color display";
    }
    textbox.setString(message);
    textbox.addCommand(exit);
    textbox.setCommandListener(this);
  }
  public void startApp() {
    display.setCurrent(textbox);
  }
  public void pauseApp() {
  }
  public void destroyApp(boolean unconditional) {
  }
  public void commandAction(Command command, Displayable displayable) {
    if (command == exit) {
      destroyApp(true);
      notifyDestroyed();
    }
  }
}

Show Properties

/*--------------------------------------------------
* ShowProperties.java
*
* Example from the book:     Core J2ME Technology
* Copyright John W. Muchow   http://www.CoreJ2ME.ru
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
public class ShowProperties extends MIDlet
{
  public void startApp() throws MIDletStateChangeException
  {
    System.out.println("Vendor: " + getAppProperty("MIDlet-Vendor"));
    System.out.println("Description: " + getAppProperty("MIDlet-Description"));
    System.out.println("JadFile Version: " + getAppProperty("JadFile-Version"));    
    System.out.println("MIDlet-Data-Size: " + getAppProperty("MIDlet-Data-Size"));    
    
    Runtime rtime = Runtime.getRuntime();
    System.out.println("Total memory: " + rtime.totalMemory());
    System.out.println("Free memory: " + rtime.freeMemory());    
  }
  public void pauseApp()
  {
  }
  public void destroyApp(boolean unconditional)
  {
  }
}