Blackberry 持久存储处理_Blackberry_Java Me

Blackberry 持久存储处理

blackberry java-me

Blackberry 持久存储处理,blackberry,java-me,Blackberry,Java Me,我正在黑莓手机上开发类似电子邮件的应用程序。我想将所有邮件存储在永久存储中。此外，还需要存储联系人列表如何使用persistet store操作此类功能如何存储数据是否可以保存多条消息如何正确访问它们并在屏幕上显示我以前从未在persistent store上工作过，请帮忙持久性存储中没有索引。您可以保存和检索持久对象数组。例如，联系Persistable： public class Contact implements Persistable{ int mId;

我正在黑莓手机上开发类似电子邮件的应用程序。我想将所有邮件存储在永久存储中。此外，还需要存储联系人列表

如何使用persistet store操作此类功能

如何存储数据

是否可以保存多条消息

如何正确访问它们并在屏幕上显示

我以前从未在persistent store上工作过，

请帮忙

持久性存储中没有索引。
您可以保存和检索持久对象数组。
例如，联系Persistable：

public class Contact implements Persistable{
    int mId; String mAdress; String mName;    
    public Contact( int id, String adress, String name ){
        mId = id; mAdress = adress; mName = name;
    }    
}

public class Mail implements Persistable{
    String mMessage = null; int mSenderId = -1; int[] mReceiverIdList = null;    
    public Mail(String message, int senderId, int[] receiverIdList){
        mMessage = message; mSenderId = senderId; 
        mReceiverIdList = receiverIdList;
    }
}

可持久化邮件：

public class Contact implements Persistable{
    int mId; String mAdress; String mName;    
    public Contact( int id, String adress, String name ){
        mId = id; mAdress = adress; mName = name;
    }    
}

public class Mail implements Persistable{
    String mMessage = null; int mSenderId = -1; int[] mReceiverIdList = null;    
    public Mail(String message, int senderId, int[] receiverIdList){
        mMessage = message; mSenderId = senderId; 
        mReceiverIdList = receiverIdList;
    }
}

一些助手类：

public class PersistentStoreHelper{
    static PersistentObject contactStore = PersistentStore
            .getPersistentObject( 0xf140775afcb94f90L );
    static PersistentObject mailStore = PersistentStore
    .getPersistentObject( 0xd43b0423228ff7c0L );
    public static void saveContacts( Contact[] contacts ){
        saveObject( contactStore, contacts );
    }
    public static void saveMails( Mail[] mails ){
        saveObject( mailStore, mails );
    }
    public static Contact[] retrieveContacts(){
        return ( Contact[] )retrieveObject( contactStore );
    }
    public static Mail[] retrieveMails(){
        return ( Mail[] )retrieveObject( mailStore );
    }
    public static void saveObject( PersistentObject store, Object object ){
        synchronized( store ){
            store.setContents( object );
            store.commit();
        }
    }
    public static Object retrieveObject( PersistentObject store ){
        Object result = null;
        synchronized( store ){
            result = store.getContents();
        }
        return result;
    }
}

和使用示例：

class Scr extends MainScreen implements FieldChangeListener{
    ButtonField mBtnInit = null;
    BasicEditField mInputSenderId = null;
    BasicEditField mInputReceiverId = null;
    ButtonField mBtnSearch = null;
    VerticalFieldManager mMailsList = null;
    public Scr(){
        mBtnInit = new ButtonField( "Init Persistenet Storage", 
            ButtonField.CONSUME_CLICK );
        mBtnInit.setChangeListener( this );
        add( mBtnInit );
        mInputSenderId = new BasicEditField( "sender id:", "43" );
        add( mInputSenderId );
        mInputReceiverId = new BasicEditField( "receiver id:", "12" );
        add( mInputReceiverId );
        mBtnSearch = new ButtonField( "Search", ButtonField.CONSUME_CLICK );
        mBtnSearch.setChangeListener( this );
        add( mBtnSearch );
        mMailsList = new VerticalFieldManager();
        add( mMailsList );
    }
    public Vector getMailByIds( int senderId, int recepientId ){
        Vector result = new Vector();
        Mail[] mails = PersistentStoreHelper.retrieveMails();
        for( int i = 0; i < mails.length; i++ )
            if( mails[ i ].mSenderId == senderId ){
                int[] receiverIdList = mails[ i ].mReceiverIdList;
                for( int j = 0; j < receiverIdList.length; j++ )
                    if( recepientId == receiverIdList[ j ] )
                        result.addElement( mails[ i ] );
            }
        return result;
    }
    public void initPersistentStorage(){
        // create 100 contacts and save them
        Contact[] contacts = new Contact[ 100 ];
        for( int i = 0; i < 100; i++ ){
            String name = "name" + String.valueOf( i );
            String adress = name + "@mail.com";
            contacts[ i ] = new Contact( i, adress, name );
        }
        PersistentStoreHelper.saveContacts( contacts );
        // create messages from each to every contact and save them
        Mail[] mails = new Mail[ 10000 - 100 ];
        int k = 0;
        for( int i = 0; i < 100; i++ )
            for( int j = 0; j < 100; j++ )
                if( i != j ){
                    Mail mail = new Mail( "Hello!", contacts[ i ].mId, 
                        new int[]{ contacts[ j ].mId } );
                    mails[ k ] = mail;
                    k++;
                }
        PersistentStoreHelper.saveMails( mails );        
    }
    public void fieldChanged( Field field, int context ){
        if( field == mBtnInit )
            initPersistentStorage();
        else if( field == mBtnSearch ){
            mMailsList.deleteAll();
            int senderId = Integer.parseInt( mInputSenderId.getText() );
            int receiverId = Integer.parseInt( mInputReceiverId.getText() );
            Contact[] contacts = PersistentStoreHelper.retrieveContacts();
            Vector result = getMailByIds( senderId, receiverId );
            for( int i = 0, cnt = result.size(); i < cnt; i++ )
            {
                Mail mail = ( Mail )result.elementAt( i );
                String from = "From: " + contacts[ mail.mSenderId ].mName 
                        + " <" + contacts[ mail.mSenderId ].mAdress + ">";
                String to = "To: ";
                for( int j = 0; j < mail.mReceiverIdList.length; j++ )
                {
                    int id = mail.mReceiverIdList[ j ];
                    to += contacts[ id ].mName + " <" 
                        + contacts[ id ].mAdress + ">; ";
                }
                to = to.substring( 0, to.length() - 2 );
                String msg = "Message: " + mail.mMessage;
                mMailsList.add( new LabelField( from ) );
                mMailsList.add( new LabelField( to ) );
                mMailsList.add( new LabelField( msg ) );
            }
        }
    }
}

类Scr扩展主屏幕实现FieldChangeListener{
按钮字段mBtnInit=null；
BasicEditField mInputSenderId=null；
BasicEditField mInputReceiverId=null；
按钮字段mBtnSearch=null；
VerticalFieldManager mMailsList=null；
公共Scr（）{
mBtnInit=新按钮字段（“Init Persistenet存储”，
ButtonField.Consument（单击）；
mBtnInit.setChangeListener（此）；
添加（mBtnInit）；
mInputSenderId=新的BasicEditField（“发件人id:，“43”）；
添加（mInputSenderId）；
MinPutReceiveId=新的基本字段（“接收方id:，“12”）；
添加（mInputReceiverId）；
mBtnSearch=新建按钮字段（“搜索”，ButtonField.consumer\u单击）；
mBtnSearch.setChangeListener（此）；
添加（mBtnSearch）；
mMailsList=新的垂直字段管理器（）；
添加（mMailsList）；
}
公共向量getMailById（int-senderId、int-recepientId）{
向量结果=新向量（）；
Mail[]Mail=PersistentStoreHelper.RetrieveMail（）；
for（int i=0；i


阅读

您还可以读取
永久存储中没有索引。

您可以保存和检索持久对象数组。

例如，联系Persistable：
public class Contact implements Persistable{
    int mId; String mAdress; String mName;    
    public Contact( int id, String adress, String name ){
        mId = id; mAdress = adress; mName = name;
    }    
}

public class Mail implements Persistable{
    String mMessage = null; int mSenderId = -1; int[] mReceiverIdList = null;    
    public Mail(String message, int senderId, int[] receiverIdList){
        mMessage = message; mSenderId = senderId; 
        mReceiverIdList = receiverIdList;
    }
}

可持久化邮件：
public class Contact implements Persistable{
    int mId; String mAdress; String mName;    
    public Contact( int id, String adress, String name ){
        mId = id; mAdress = adress; mName = name;
    }    
}

public class Mail implements Persistable{
    String mMessage = null; int mSenderId = -1; int[] mReceiverIdList = null;    
    public Mail(String message, int senderId, int[] receiverIdList){
        mMessage = message; mSenderId = senderId; 
        mReceiverIdList = receiverIdList;
    }
}

一些助手类：
public class PersistentStoreHelper{
    static PersistentObject contactStore = PersistentStore
            .getPersistentObject( 0xf140775afcb94f90L );
    static PersistentObject mailStore = PersistentStore
    .getPersistentObject( 0xd43b0423228ff7c0L );
    public static void saveContacts( Contact[] contacts ){
        saveObject( contactStore, contacts );
    }
    public static void saveMails( Mail[] mails ){
        saveObject( mailStore, mails );
    }
    public static Contact[] retrieveContacts(){
        return ( Contact[] )retrieveObject( contactStore );
    }
    public static Mail[] retrieveMails(){
        return ( Mail[] )retrieveObject( mailStore );
    }
    public static void saveObject( PersistentObject store, Object object ){
        synchronized( store ){
            store.setContents( object );
            store.commit();
        }
    }
    public static Object retrieveObject( PersistentObject store ){
        Object result = null;
        synchronized( store ){
            result = store.getContents();
        }
        return result;
    }
}

和使用示例：
class Scr extends MainScreen implements FieldChangeListener{
    ButtonField mBtnInit = null;
    BasicEditField mInputSenderId = null;
    BasicEditField mInputReceiverId = null;
    ButtonField mBtnSearch = null;
    VerticalFieldManager mMailsList = null;
    public Scr(){
        mBtnInit = new ButtonField( "Init Persistenet Storage", 
            ButtonField.CONSUME_CLICK );
        mBtnInit.setChangeListener( this );
        add( mBtnInit );
        mInputSenderId = new BasicEditField( "sender id:", "43" );
        add( mInputSenderId );
        mInputReceiverId = new BasicEditField( "receiver id:", "12" );
        add( mInputReceiverId );
        mBtnSearch = new ButtonField( "Search", ButtonField.CONSUME_CLICK );
        mBtnSearch.setChangeListener( this );
        add( mBtnSearch );
        mMailsList = new VerticalFieldManager();
        add( mMailsList );
    }
    public Vector getMailByIds( int senderId, int recepientId ){
        Vector result = new Vector();
        Mail[] mails = PersistentStoreHelper.retrieveMails();
        for( int i = 0; i < mails.length; i++ )
            if( mails[ i ].mSenderId == senderId ){
                int[] receiverIdList = mails[ i ].mReceiverIdList;
                for( int j = 0; j < receiverIdList.length; j++ )
                    if( recepientId == receiverIdList[ j ] )
                        result.addElement( mails[ i ] );
            }
        return result;
    }
    public void initPersistentStorage(){
        // create 100 contacts and save them
        Contact[] contacts = new Contact[ 100 ];
        for( int i = 0; i < 100; i++ ){
            String name = "name" + String.valueOf( i );
            String adress = name + "@mail.com";
            contacts[ i ] = new Contact( i, adress, name );
        }
        PersistentStoreHelper.saveContacts( contacts );
        // create messages from each to every contact and save them
        Mail[] mails = new Mail[ 10000 - 100 ];
        int k = 0;
        for( int i = 0; i < 100; i++ )
            for( int j = 0; j < 100; j++ )
                if( i != j ){
                    Mail mail = new Mail( "Hello!", contacts[ i ].mId, 
                        new int[]{ contacts[ j ].mId } );
                    mails[ k ] = mail;
                    k++;
                }
        PersistentStoreHelper.saveMails( mails );        
    }
    public void fieldChanged( Field field, int context ){
        if( field == mBtnInit )
            initPersistentStorage();
        else if( field == mBtnSearch ){
            mMailsList.deleteAll();
            int senderId = Integer.parseInt( mInputSenderId.getText() );
            int receiverId = Integer.parseInt( mInputReceiverId.getText() );
            Contact[] contacts = PersistentStoreHelper.retrieveContacts();
            Vector result = getMailByIds( senderId, receiverId );
            for( int i = 0, cnt = result.size(); i < cnt; i++ )
            {
                Mail mail = ( Mail )result.elementAt( i );
                String from = "From: " + contacts[ mail.mSenderId ].mName 
                        + " <" + contacts[ mail.mSenderId ].mAdress + ">";
                String to = "To: ";
                for( int j = 0; j < mail.mReceiverIdList.length; j++ )
                {
                    int id = mail.mReceiverIdList[ j ];
                    to += contacts[ id ].mName + " <" 
                        + contacts[ id ].mAdress + ">; ";
                }
                to = to.substring( 0, to.length() - 2 );
                String msg = "Message: " + mail.mMessage;
                mMailsList.add( new LabelField( from ) );
                mMailsList.add( new LabelField( to ) );
                mMailsList.add( new LabelField( msg ) );
            }
        }
    }
}

类Scr扩展主屏幕实现FieldChangeListener{
按钮字段mBtnInit=null；
BasicEditField mInputSenderId=null；
BasicEditField mInputReceiverId=null；
按钮字段mBtnSearch=null；
VerticalFieldManager mMailsList=null；
公共Scr（）{
mBtnInit=新按钮字段（“Init Persistenet存储”，
ButtonField.Consument（单击）；
mBtnInit.setChangeListener（此）；
添加（mBtnInit）；
mInputSenderId=新的BasicEditField（“发件人id:，“43”）；
添加（mInputSenderId）；
MinPutReceiveId=新的基本字段（“接收方id:，“12”）；
添加（mInputReceiverId）；
mBtnSearch=新建按钮字段（“搜索”，ButtonField.consumer\u单击）；
mBtnSearch.setChangeListener（此）；
添加（mBtnSearch）；
mMailsList=新的垂直字段管理器（）；
添加（mMailsList）；
}
公共向量getMailById（int-senderId、int-recepientId）{
向量结果=新向量（）；
Mail[]Mail=PersistentStoreHelper.RetrieveMail（）；
for（int i=0；i