By: Ivan LimThe CLDC/MIDP supports system properties, which are key-value pairs that represent information about the platform and environment in which MIDP applications execute. Conceptually these are the same type of properties that you find in J2SE. Unfortunately, there is no java.util.Properties class in CLDC/MIDP to facilitate your handling of properties.
The MIDP specification defines only a small set of standard
properties, which are shown in Table
3.4. Implementations may support additional, manufacturer-specific system properties, but these
are nonstandard. You should be aware of what manufacturer- or platform-specific features you use
in order to anticipate portability issues.
Like J2SE applications, MIDP applications can retrieve a system property using the
java.lang.System class. To retrieve the value of a property, use the System class method
String getProperty(String key)
This method retrieves the property value associated with the key whose value is specified in the
Standard CLDC System Properties
|Property||Key Description||Default Value|
|microedition.configuration||Name and version of the supported configuration||CLDC-1.0|
|microedition.encoding||Default character encoding set used by the platform||ISO8859-1|
|microedition.locale||Name of the platform's current locale||null|
|microedition.platform||Name of the host platform or device||null|
|microedition.profiles||Names of all supported profiles||null|
A sample J2ME program illustrates the retrieval of system properties in a MIDlet.
MIDlets have direct access to all four of the standard system properties defined by the CLDC specification.
Creates the "Hello world" program in J2ME MIDP.
Note that the class must be public so that the device
application management software can instantiate it.
public class HelloWorld extends MIDlet
public void startApp()
// Create a Displayable widget.
form = new Form("Hello World");
// Add a string to the form.
String msg = "My first MIDlet!";
// This app simply displays the single form created
display = Display.getDisplay(this);
Prints the values of the standard system properties
using the System.getProperty() call.
protected void printSystemProperties()
conf = System.getProperty("microedition.configuration");
profiles = System.getProperty("microedition.profiles");
platform = System.getProperty("microedition.platform");
encoding = System.getProperty("microedition.encoding");
locale = System.getProperty("microedition.locale");
Notice the addition of the call to the method printSystemProperties() at the end of the startApp() method. This method simply retrieves and prints to standard output the values of the five standard MIDP system properties. The data that the program writes to standard output is shown next:\
1. That worked great. Thanks for the the tutorial. +1 ed this post & best of luck.
View Tutorial By: Arman Hossain at 2011-10-20 13:27:30
2. Please tell me the process, how to compile the midlet. I have a wtk2.5.0 and jdk1.5.0 send me one e
View Tutorial By: Manish at 2008-11-14 13:33:43
3. I am looking for a J2ME programmer that can create a simple application that sends a cellular phones
View Tutorial By: Gary Wallis at 2007-10-14 15:35:00
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