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永続ストアに格納するオブジェクトのサイズを調べようとしています。コードで示されているように、プログラムでオブジェクトのサイズがわかりましたが、永続ストアに格納されているときにこのオブジェクトのサイズがわかりません。 データを格納するときに自動的に圧縮されますか？私はMemory.getFlashStats（）を使用しています。getFree（）;ストアするオブジェクトの前と後に永続ストアの空きサイズを取得し、2つの値の差は、計算したオブジェクトのサイズと等しくなければなりません。同じオブジェクトの数倍のストレージを測定するとき コードブラックベリーの永続ストアに格納されているオブジェクトのサイズ（バイトまたはkb、mb）を調べる方法
package Bean;
import java.util.Enumeration;
import java.util.Vector;
import net.rim.device.api.system.Memory;
import net.rim.device.api.system.MemoryStats;
import net.rim.device.api.system.PersistentObject;
import net.rim.device.api.system.PersistentStore;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FieldChangeListener;
import net.rim.device.api.ui.MenuItem;
import net.rim.device.api.ui.component.ButtonField;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.EditField;
import net.rim.device.api.ui.container.MainScreen;
import bean.UserCredentials;
public class MyStoreScreen extends MainScreen implements FieldChangeListener
{
private int nObjectSize;
static final long PERSISTENT_STORE_DEMO_ID = 0x42c16456ab0b5eabL;
private static PersistentObject oPersistenStore;
private int nFreePersistenceInStarting=Memory.getPersistentStats().getFree();
private int nFreePersistenceAtEnd;
ButtonField oCalculateMemButton ;
private MenuItem saveItem = new MenuItem("Save ", 110, 10)
{
public void run()
{
Dialog.alert("initially free memory ----------------------"+nFreePersistenceInStarting);
oPersistenStore = PersistentStore.getPersistentObject(PERSISTENT_STORE_DEMO_ID);
Vector storeVector = (Vector)oPersistenStore.getContents();
Vector userinfo ;
int size = (storeVector == null) ? 0 : storeVector.size();
if(size == 0)
{
userinfo = new Vector();
}
else
{
userinfo = storeVector;
}
UserCredentials oUserCredentials = new UserCredentials("akanksha","chandra",1,3434.3434,343545646);
for(int i =0;i<=100;i++)
{
userinfo.addElement(oUserCredentials);
}
nObjectSize= fnCalculateSizeOfObject(userinfo);
Dialog.alert("size of object is "+ nObjectSize);
synchronized(oPersistenStore)
{
oPersistenStore.setContents(userinfo);
oPersistenStore.commit();
}
}
};
private MenuItem getItem = new MenuItem("Get item", 110, 11)
{
public void run()
{
oPersistenStore = PersistentStore.getPersistentObject(PERSISTENT_STORE_DEMO_ID);
synchronized(oPersistenStore)
{
Vector arrCredential = (Vector)oPersistenStore.getContents();
if(arrCredential != null)
{
String dataContents = "";
int nSize = (arrCredential == null) ? 0 : arrCredential.size();
if(nSize != 0)
{
for (int i = 0; i < nSize; i++)
{
UserCredentials oUserCredentials = (UserCredentials)arrCredential.elementAt(i);
dataContents+="\n size of vector is "+nSize+ " username : "+oUserCredentials.getStrUsername()+"\n password : "+oUserCredentials.getStrPassword();
dataContents += "\n\nUser sal : "+oUserCredentials.getdSalary();
dataContents += "\n amount : "+oUserCredentials.getlAmount();
dataContents += "\n s no "+oUserCredentials.getnSerialNo();
}
Dialog.alert(dataContents);
}
else
{
Dialog.alert("Zero Elements ");
}
}
else
{
Dialog.alert("No contents ");
}
}
}
};
private MenuItem resetStoreItem = new MenuItem("Delete Store", 110, 11)
{
public void run()
{
int choice = Dialog.ask(Dialog.D_OK_CANCEL, "Do you want to delete ?");
if(choice == Dialog.D_OK)
{
// oPersistenStore = PersistentStore.getPersistentObject(PERSISTENT_STORE_DEMO_ID);
PersistentStore.destroyPersistentObject(PERSISTENT_STORE_DEMO_ID);
}
else
{
}
}
};
private MenuItem CalculateTotalFlashUsed = new MenuItem("calculate used flash size ", 0, 7)
{
public void run()
{
Dialog.alert("used size of Persistence Store is "+fnUsedPersistenceSize());
};
};
public MyStoreScreen()
{
oCalculateMemButton = new ButtonField("calculate free flash memory in starting", ButtonField.CONSUME_CLICK);
oCalculateMemButton.setChangeListener(this);
this.add(oCalculateMemButton);
this.addMenuItem(saveItem);
this.addMenuItem(getItem);
this.addMenuItem(resetStoreItem);
this.addMenuItem(CalculateTotalFlashUsed);
oPersistenStore = PersistentStore.getPersistentObject(PERSISTENT_STORE_DEMO_ID);
}
public void fieldChanged(Field field, int context)
{
if(field ==oCalculateMemButton)
{
// nFreeFlashInStarting =Memory.getFlashTotal();
// nFreeFlashInStarting =Memory.getFlashStats().getFree();
// nFreeFlashAtEnd =Memory.getFlashStats().getFree();
// String message = "total flash is Memory.getFlashStats().getAllocated(); "+nFreeFlashInStarting+" Memory.getFlashTotal() is : "+Memory.getFlashTotal();
String message = "total free flash memory in starting is :"+ nFreePersistenceInStarting;
Dialog.alert(message);
}
}
private int fnCalculateSizeOfObject(Vector userInfo)
{
int nSize = 0;
Enumeration oEnumeration = userInfo.elements();
while(oEnumeration.hasMoreElements())
{
UserCredentials oUserCredentials = (UserCredentials) oEnumeration.nextElement();
String UserName = oUserCredentials.getStrUsername();
String password = oUserCredentials.getStrPassword();
int nSerialNo = oUserCredentials.getnSerialNo();
double dSalary = oUserCredentials.getdSalary();
long lAmount = oUserCredentials.getlAmount();
nSize+= 4+8+8+fnCalculateSizeOfString(UserName)+fnCalculateSizeOfString(password);
}
return nSize;
}
private int fnCalculateSizeOfString(String strInputString)
{
//convert String to char array
char[] characterArray = strInputString.toCharArray();
int nlength = characterArray.length;
return nlength;
}
public int fnUsedPersistenceSize()
{
nFreePersistenceAtEnd = Memory.getPersistentStats().getFree();
int nUsedPersistenceMemory = nFreePersistenceInStarting -nFreePersistenceAtEnd;
return nUsedPersistenceMemory;
}
}