软件名称：RMS容量探测器
作者简介：詹建飞(mingjava)，北京邮电大学信息工程学院信号与信息处理专业研究生。
电子信箱：
eric.zhan@263.net
之所以写这个RMS容量探测器是因为我在nokia 6108手机上编写个人通信录的时候想知道它的RecordStore最大有多少空间可以使用。我调用getSizeAviable()的时候发现它返回的值几乎等于手机上剩余的内存空间的值，因此我想这个API的实现是错误的。于是编写了这个简单的RMS容量探测器，它能探测手机上一个RecordStore能存储数据的最大值，单位是K字节,请不要在模拟器上运行这个软件，这没有任何意义。下面简单介绍一下实现。
由于软件比较小，因此我没有应用MVC的设计模式，如果编写较大的应用程序一定要使用MVC。软件一共有三个类:CounterCanvas,RMSAnalyzer和RMSModel。软件的原理是：新建一个RecordStore然后每隔100ms往里面写入1K的数据，在退出的时候删除这个RecordStore。思路非常简单！代码也不复杂，因此我直接给出源代码。你可以从这里下载源文件(其中包括jar文件和jad文件)。如果提供下载请注明出处和作者
import javax.microedition.rms.*;
public class RMSModel
{
public static final int K = 1024;
private RecordStore rs;
private int baseCount;
private RMSAnalyzer RMSanalyzer;
public static final String name = "test";
public RMSModel(int baseCount, RMSAnalyzer rmsa)
throws RecordStoreException
{
this.baseCount = baseCount;
this.RMSanalyzer = rmsa;
if (rs == null)
{
rs = RecordStore.openRecordStore(name, true);
writeRecord(baseCount);
}
}
public void writeRecord(int count) throws RecordStoreException
{
byte[] data = new byte[count * K];
for (int i = 0; i < count; i++)
{
data[i] = 1;
}
rs.addRecord(data, 0, count * K);
}
public void deleteRMS()
{
try
{
rs.closeRecordStore();
RecordStore.deleteRecordStore(name);
} catch (RecordStoreException e)
{
RMSanalyzer.showAlertError(e.getMessage());
}
}
}
import java.io.IOException;
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.Image;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.rms.RecordStoreException;
public class RMSAnalyzer extends MIDlet implements CommandListener
{
private Display display;
private CounterCanvas counterCanvas;
private Alert alert;
public static final Command startCommand = new Command("开始", Command.ITEM,
1);
public static final Command exitCommand = new Command("退出", Command.EXIT, 2);
protected void startApp() throws MIDletStateChangeException
{
display = Display.getDisplay(this);
alert = new Alert("错误提示");
try
{
String interval = this.getAppProperty("INTER");
int t = Integer.parseInt(interval);
counterCanvas = new CounterCanvas(t, 0, this);
} catch (RecordStoreException e)
{
this.showAlertError(e.getMessage());
}
Form mainForm = new Form("RMS测试器");
Image mainImage = getMainImage("java.png");
if (mainImage != null)
{
mainForm.append(mainImage);
} else
{
mainForm.append("欢迎使用自由软件");
}
mainForm.addCommand(startCommand);
mainForm.addCommand(exitCommand);
mainForm.setCommandListener(this);
display.setCurrent(mainForm);
}
public Image getMainImage(String name)
{
Image image = null;
try
{
image = Image.createImage("/" + name);
} catch (IOException e)
{
return null;
}
return image;
}
public Display getDisplay()
{
return display;
}
protected void pauseApp()
{
}
protected void destroyApp(boolean arg0) throws MIDletStateChangeException
{
}
public void commandAction(Command cmd, Displayable disp)
{
if (cmd == startCommand)
{
display.setCurrent(counterCanvas);
counterCanvas.start();
} else if (cmd == exitCommand)
{
exitMIDlet();
}
}
public void exitMIDlet()
{
try
{
destroyApp(false);
notifyDestroyed();
} catch (MIDletStateChangeException e)
{
showAlertError(e.getMessage());
}
}
public void showAlertError(String message)
{
alert.setString(message);
alert.setType(AlertType.ERROR);
alert.se
