原文地址
相信做手機開發(fā)的都知道，write once debug anywhere。你向從中體驗樂趣嗎，那先來了解下手機對JSR規(guī)范的支持吧。
下面是我從網(wǎng)絡(luò)上獲取一些的信息。
其中一個源代碼出自http://www.javaeye.com/topic/75387
大家可以到上面下載源代碼，然后稍微修改下，就可以提供對jsr的更多測試了。
關(guān)于測試的方面看下面
For instance, the property microedition.commports is present in the
MIDP 2.0 specification. Its value is a comma-separated list of ports
you can use to build a URL, which the Generic Connection Framework can
in turn use to create a javax.microedition.io.CommConnection object.
To query system properties use java.lang.System.getProperty(), as in:
import java.lang.*;
String value;
String key = "microedition.pim.version";
value = System.getProperty( key );
...
This
table lists the defined system properties, drawing them from JSRs that
are in the public review, final ballot, or final state, as defined in
the Java Community Process (JCP):
J2ME Defined System Properties
JSR Property Name
Default Value¹
30 microedition.platform null
microedition.encoding ISO8859_1
microedition.configuration CLDC-1.0
microedition.profiles null
37 microedition.locale null
microedition.profiles MIDP-1.0
75 microedition.io.file.FileConnection.version 1.0
file.separator (impl-dep)
microedition.pim.version 1.0
118 microedition.locale null
microedition.profiles MIDP-2.0
microedition.commports (impl-dep)
microedition.hostname (impl-dep)
120 wireless.messaging.sms.smsc (impl-dep)
139 microedition.platform (impl-dep)
microedition.encoding ISO8859-1
microedition.configuration CLDC-1.1
microedition.profiles (impl-dep)
177 microedition.smartcardslots (impl-dep)
179 microedition.location.version 1.0
180 microedition.sip.version 1.0
184 microedition.m3g.version 1.0
185 microedition.jtwi.version 1.0
195 microedition.locale (impl-dep)
microedition.profiles IMP-1.0
205 wireless.messaging.sms.smsc (impl-dep)
205 wireless.messaging.mms.mmsc (impl-dep)
211 CHAPI-Version 1.0
這個是e文的
看看中文的吧
2.3.4 MIDP應(yīng)用程序的屬性
MIDlet可以訪問兩種運行時的屬性值：系統(tǒng)屬性和應(yīng)用程序?qū)傩浴?/font>
1．系統(tǒng)屬性
系統(tǒng)屬性是在CLDC（Connected Limited Device Configuration）中定義的，屬性值被寫入底層的系統(tǒng)，我們可以讀取它們，但是不能修改這些屬性值。如果想讀取一個系統(tǒng)屬性值，那么可以使用System類的靜態(tài)方法System.getProperty()來讀取。有時候我們可能想讀取特定手機的系統(tǒng)信息，比如IMEI號。解決辦法就是去參考這款手機的開發(fā)指南和規(guī)范，比如，從SonyEricsson系列手機讀取IMEI號，調(diào)用方法：System.getProperty ("com. onyericsson.imei")，這時將返回手機的IMEI號碼，如IMEI 123456-00-123456-1-00。需要說明的一點是，在SonyEricsson P910上查詢IMEI號碼時，傳遞的字符串參數(shù)應(yīng)該是com.sonyericsson.IMEI（IMEI須大寫）。如果在不支持此項功能的手機上查詢IMEI號時，將什么都不返回，例如，在T610上調(diào)用。
表2-3列舉了系統(tǒng)屬性。
表2-3 MIDP應(yīng)用程序系統(tǒng)屬性
|
JSR
|
屬性名稱
|
默 認(rèn) 值
|
|
30
|
microedition.platform
|
null
|
|
|
microedition.encoding
|
ISO8859_1
|
|
|
microedition.configuration
|
CLDC-1.0
|
|
|
microedition.profiles
|
null
|
|
37
|
microedition.locale
|
null
|
|
|
microedition.profiles
|
MIDP-1.0
|
|
75
|
microedition.io.file.FileConnection.version
|
1.0
|
|
|
file.separator
|
依賴于底層實現(xiàn)
|
|
|
microedition.pim.version
|
1.0
|
|
118
|
microedition.locale
|
null
|
|
|
microedition.profiles
|
MIDP-2.0
|
|
|
microedition.commports
|
依賴于底層實現(xiàn)
|
|
|
microedition.hostname
|
依賴于底層實現(xiàn)
|
|
120
|
wireless.messaging.sms.smsc
|
依賴于底層實現(xiàn)
|
|
139
|
microedition.platform
|
依賴于底層實現(xiàn)
|
|
|
microedition.encoding
|
ISO8859-1
|
|
|
microedition.configuration
|
CLDC-1.1
|
|
|
microedition.profiles
|
依賴于底層實現(xiàn)
|
|
177
|
microedition.smartcardslots
|
依賴于底層實現(xiàn)
|
|
179
|
microedition.location.version
|
1.0
|
|
180
|
microedition.sip.version
|
1.0
|
|
184
|
microedition.m3g.version
|
1.0
|
|
185
|
microedition.jtwi.version
|
1.0
|
|
195
|
microedition.locale
|
依賴于底層實現(xiàn)
|
|
|
microedition.profiles
|
IMP-1.0
|
|
205
|
wireless.messaging.sms.smsc
|
依賴于底層實現(xiàn)
|
|
205
|
wireless.messaging.mms.mmsc
|
依賴于底層實現(xiàn)
|
2．應(yīng)用程序?qū)傩?/font>
應(yīng)用程序?qū)傩灾凳窃趹?yīng)用程序描述符文件或者MANIFEST文件中定義的，當(dāng)我們部署應(yīng)用程序的時候可以定義應(yīng)用程序?qū)傩浴１热缦旅媸且粋€典型的JAD文件內(nèi)容。
MIDlet-1: HttpWrapperMidlet,httpwrapper.HttpWrapperMIDlet
MIDlet-Jar-Size: 16315
MIDlet-Jar-URL: HttpWrapper.jar
MIDlet-Name: HttpWrapper
MIDlet-Vendor: Vendor
MIDlet-Version: 1.0
MicroEdition-Configuration: CLDC-1.0
MicroEdition-Profile: MIDP-1.0
Which-Locale: en
其中Which-Locale就是應(yīng)用程序?qū)傩灾?，我們可以通過MIDlet的成員方法getAppProperty()來得到它，代碼片斷如下：
import javax.microedition.midlet.*;
public class MyMIDlet extends MIDlet {
private String suiteName;
private String which_locale;
public MyMIDlet(){
suiteName = getAppProperty( "MIDlet-Name" );
which_locale = getAppProperty("Which-Locale");
}
//這里省略了其他代碼
}
屬性值對大小寫是敏感的，如果屬性值在底層系統(tǒng)、JAD文件和Manifest文件中都沒有定義的話，那么將返回Null。
熟悉MIDP應(yīng)用程序的系統(tǒng)屬性對我們開發(fā)靈活、強大的MIDlet至關(guān)重要。可以根據(jù)系統(tǒng)屬性返回值來動態(tài)地生成應(yīng)用程序的菜單。例如，通過判斷底層系統(tǒng)是否支持MMAPI來決定應(yīng)用程序中是否要添加攝像功能。下面的例子演示了如何在MIDlet中讀取系統(tǒng)屬性。
package com.j2medev.ch3.property;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class DetectMIDlet extends MIDlet {
private static DetectMIDlet instance = null;
private Display display = null;
private Displayable form = null;
public DetectMIDlet() {
instance = this;
}
protected void startApp() {
if(display==null) {
//首次啟動應(yīng)用程序
display = Display.getDisplay(this);
form = new TestForm();
display.setCurrent(form);
} else{
display.setCurrent(form);
}
}
protected void pauseApp() {}
protected void destroyApp(boolean unconditional) {}
public static void quitApp() {
instance.destroyApp(true);
instance.notifyDestroyed();
instance = null;
}
}
class TestForm extends Form implements CommandListener {
private Command exit = new Command("退出", Command.EXIT, 0);
public TestForm() {
super("J2ME平臺測試");
String s;
//CLDC版本屬性
s = System.getProperty("microedition.configuration");
append(getValue("CLDC版本", s));
//MIPD版本屬性
s = System.getProperty("microedition.profiles");
append(getValue("MIDP版本",s));
s = System.getProperty("microedition.platform");
append(getValue("軟件平臺", s));
s = System.getProperty("microedition.encoding");
append(getValue("系統(tǒng)編碼", s));
s = System.getProperty("microedition.locale");
append(getValue("區(qū)域設(shè)置", s));
s = System.getProperty("microedition.jtwi.version");
append(getValue("JTWI", s));
//判斷是否支持MMAPI
s = System.getProperty("microedition.media.version");
append(getValue("MMAPI", s));
//判斷是否支持WMA
s = System.getProperty("wireless.messaging.sms.smsc");
if(s!=null) {
append(getValue("WMA", "支持"));
append(getValue("SMS", s));
s = System.getProperty("wireless.messaging.mms.mmsc");
append(getValue("MMS", s));
} else
append(getValue("WMA", null));
//判斷是否支持藍牙
s = System.getProperty("bluetooth.api.version");
append(getValue("藍牙", s));
//判斷是否支持個人信息管理
s = System.getProperty("microedition.pim.version");
append(getValue("PIM", s));
//判斷是否支持文件系統(tǒng)
s=System.getProperty("microedition.io.file.FileConnection. version");
append(getValue("FileConnection", s));
//判斷是否支持SIP
s = System.getProperty("microedition.sip.version");
append(getValue("SIP", s));
//判斷是否支持M3G JSR 184
s = System.getProperty("microedition.m3g.version");
append(getValue("M3G", s));
addCommand(exit);
setCommandListener(this);
}
private String getValue(String prompt, String s) {
return prompt + "：" + (s==null ? "不支持" : s) + "\n";
}
public void commandAction(Command c, Displayable d) {
if(c==exit){
DetectMIDlet.quitApp();
}
}
}
DetectMIDlet的運行界面如圖2-19所示。
圖2-19 DetectMIDlet的運行界面
這篇文章只是整理這方面的知識，并不是原創(chuàng)。所以大家湊合著看吧