What's the code for the regexp that you are trying & what is the source
string that you are matching against.

On Thu, May 7, 2009 at 3:24 PM, Evan Ruff <[email protected]> wrote:

>
> Vitali,
>
> Thanks for your response!
>
> That RegExp for the ? was giving me trouble, as it wouldn't match.
>
> I also tried [\\?] without success as well. Any idea on how to find
> that guy?
>
> Thanks,
>
> E
>
> On May 7, 2:59 pm, Vitali Lovich <[email protected]> wrote:
> > Javascript & Java have different regular expressions, so if you are
> running
> > your stuff on desktop browsers in Hosted Mode but compiled mode in
> Android,
> > then you might be running into that problem.
> >
> > A performance improvement should be:
> >
> > String statement = new String( sqlStatement );
> > StringBuffer sb = new StringBuffer(statement.length());
> > int index;
> > int previous = 0;
> > int i = 0;
> >
> > while ((index = statement.indexOf('?')) != -1)
> > {
> >    String firstPart = statement.substring( previous, index );
> >    sb.append (firstPart).append('"').append(params[i++]).append('"');
> >    previous = index + 1;
> >
> > }
> >
> > return sb.toString();
> >
> > or try
> >
> > String statement = new String( sqlStatement );
> > String [] parts = statement.split("[?]");
> > StringBuffer sb = new StringBuffer(statement.length + parts.length *
> > AVERAGE_PARAM_LENGTH);
> >
> > for (int i = 0; i < parts.length; i++)
> > {
> >    sb.append(parts[i]).append('"').append(params[i]).append('"')
> >
> > }
> >
> > AVERAGE_PARAM_LENGTH can be anything, but you want the resultant
> expression
> > to be as close as possible to the actual final length as possible,
> without
> > going under (assuming this portion of code is your hotpath - otherwise,
> you
> > won't notice the difference).
> >
> > On Thu, May 7, 2009 at 2:12 PM, Evan Ruff <[email protected]> wrote:
> >
> > > Ok so something really fishy is going on with the Gears API.
> >
> > > I created my own "prepareSQLStatement" that converts the SQL Call and
> > > parameter list into a string.
> >
> > >        private String prepareSQLStatement( String sqlStatement,
> String[]
> > > params ) throws DatabaseException
> > >        {
> > >                try
> > >                {
> > >                        String statement = new String( sqlStatement );
> >
> > >                        for ( int i = 0; ( statement.indexOf( "?" ) > 0
> );
> > > i++ )
> > >                        {
> > >                                int index = statement.indexOf( '?' );
> > >                                String firstPart = statement.substring(
> 0,
> > > index );
> > >                                String secondPart = statement.substring(
> > > index + 1 );
> >
> > >                                StringBuffer sb = new StringBuffer();
> > >                                sb.append( firstPart ).append( "\""
> > > ).append( params[ i ] ).append
> > > ( "\"" ).append( secondPart );
> > >                                statement = sb.toString();
> > >                        }
> >
> > >                        return statement;
> > >                }
> > >                catch ( IndexOutOfBoundsException indexOut )
> > >                {
> > >                        throw new DatabaseException( "Index out of
> bounds.
> > > SQL Parameter
> > > Error" );
> > >                }
> > >        }
> >
> > > When I use this method to prepare the statement before hitting
> > > db.execute, all of my sql statements work as expected.
> >
> > > Could Android implement it's string manipulation stack slightly
> > > differently than all the other platforms? I've got a sneaky suspecion
> > > that the RegExp that's used to parse the '?' in the SQL commands might
> > > be failing?
> >
> > > Furthermore, can anyone give me an ideas as how to improve the
> > > performance of the above method? It creates a noticable delay. Did I
> > > read somewhere that GWT has a slow string manipulation engine?
> >
> > > E
> >
> > > On May 6, 2:07 pm, Evan Ruff <[email protected]> wrote:
> > > > Hey Eric,
> >
> > > > I'm pretty much terrified of Javascript.
> >
> > > > I'm a little hesitant to make any determination whatsoever as to the
> > > > cause of the problem. When I run the GWT Gears Sample DatabaseDemo
> > > > project, it works as expected. I can even replace all of the DB
> > > > specifics with the internals of my tables/queries and it seems to
> > > > work! It's just so freakin' frustrating.
> >
> > > > RememberTheMilk and the mobile GMail seem to make use of Gears on
> > > > Android without issue, so I really don't know where to go from here.
> > > > Any other suggestions?
> >
> > > > Here's the replaced DatabaseDemo code, fwiw:
> >
> > > > public class Gears implements EntryPoint
> > > > {
> > > >         private static final int NUM_SAVED_ROWS = 3;
> > > >         private static final int NUM_DATA_TABLE_COLUMNS = 3;
> >
> > > >         private final Button addButton = new Button( "Add" );
> > > >         private final Button clearButton = new Button( "Clear
> Database"
> > > );
> > > >         private Database db;
> > > >         private final TextBox input = new TextBox();
> > > >         private final FlexTable dataTable = new FlexTable();
> >
> > > >         public void onModuleLoad()
> > > >         {
> > > >                 VerticalPanel outerPanel = new VerticalPanel();
> > > >                 outerPanel.setSpacing( 10 );
> > > >                 outerPanel.getElement().getStyle().setPropertyPx(
> > > "margin", 15 );
> >
> > > >                 HorizontalPanel textAndButtonsPanel = new
> > > HorizontalPanel();
> > > >                 textAndButtonsPanel.add( new Label( "Enter a Phrase:
> " )
> > > );
> > > >                 textAndButtonsPanel.add( input );
> > > >                 textAndButtonsPanel.add( addButton );
> > > >                 textAndButtonsPanel.add( clearButton );
> > > >                 outerPanel.add( textAndButtonsPanel );
> > > >                 outerPanel.add( new Label( "Last 3 Entries:" ) );
> > > >                 outerPanel.add( dataTable );
> >
> > > >                 for ( int i = 0; i <= NUM_SAVED_ROWS; ++i )
> > > >                 {
> > > >                         dataTable.insertRow( i );
> > > >                         for ( int j = 0; j < NUM_DATA_TABLE_COLUMNS;
> j++
> > > )
> > > >                         {
> > > >                                 dataTable.addCell( i );
> > > >                         }
> > > >                 }
> > > >                 dataTable.setWidget( 0, 0, new HTML( "<b>Id</b>" ) );
> > > >                 dataTable.setWidget( 0, 1, new HTML( "<b>Phrase</b>"
> ) );
> > > >                 dataTable.setWidget( 0, 2, new HTML(
> "<b>Timestamp</b>" )
> > > );
> >
> > > >                 // Create the database if it doesn't exist.
> > > >                 try
> > > >                 {
> > > >                         db = Factory.getInstance().createDatabase();
> > > >                         db.open( "database-demo" );
> >
> > > >                         db.execute( "DROP TABLE IF EXISTS user" );
> > > >                         db.execute( "CREATE TABLE IF NOT EXISTS user
> (
> > > user_id TEXT NOT
> > > > NULL, sessionId TEXT, name TEXT, email TEXT )" );
> > > >                 }
> > > >                 catch ( DatabaseException e )
> > > >                 {
> > > >                         RootPanel.get( "demo" ).add( new HTML( "Error
> > > opening or creating
> > > > database: <font color=\"red\">" + e.toString() + "</font>" ) );
> > > >                         // Fatal error. Do not build the interface.
> > > >                         return;
> > > >                 }
> >
> > > >                 input.addKeyboardListener( new
> KeyboardListenerAdapter()
> > > >                 {
> > > >                         @Override
> > > >                         public void onKeyDown( Widget sender, char
> > > keyCode, int modifiers )
> > > >                         {
> > > >                                 if (keyCode ==
> > > KeyboardListener.KEY_ENTER)
> > > >                                 {
> > > >                                         insertPhrase();
> > > >                                 }
> > > >                         }
> > > >                 } );
> >
> > > >                 addButton.addClickListener( new ClickListener()
> > > >                 {
> > > >                         public void onClick( Widget sender )
> > > >                         {
> > > >                                 insertPhrase();
> > > >                         }
> > > >                 } );
> >
> > > >                 clearButton.addClickListener( new ClickListener()
> > > >                 {
> > > >                         public void onClick( Widget sender )
> > > >                         {
> > > >                                 clearPhrases();
> > > >                                 displayRecentPhrases();
> > > >                         }
> > > >                 } );
> >
> > > >                 RootPanel.get( "demo" ).add( outerPanel );
> > > >                 displayRecentPhrases();
> > > >         }
> >
> > > >         /**
> > > >          * Remove all phrases from the database.
> > > >          */
> > > >         private void clearPhrases()
> > > >         {
> > > >                 try
> > > >                 {
> > > >                         db.execute( "DELETE FROM Phrases" );
> > > >                 }
> > > >                 catch ( DatabaseException e )
> > > >                 {
> > > >                         Window.alert( e.toString() );
> > > >                 }
> > > >         }
> >
> > > >         /**
> > > >          * Fill the labels with the phrases from the database.
> > > >          */
> > > >         private void displayRecentPhrases()
> > > >         {
> > > >                 try
> > > >                 {
> > > >                         ResultSet rs = db.execute( "SELECT name,
> email
> > > FROM user" );
> > > >                         int i;
> >
> > > >                         for ( i = 1; rs.isValidRow(); ++i, rs.next()
> )
> > > >                         {
> > > >                                 if (i <= NUM_SAVED_ROWS)
> > > >                                 {
> > > >                                         dataTable.setText( i, 0, i+""
> );
> > > >                                         dataTable.setText( i, 1,
> > > rs.getFieldAsString( 0 ) );
> > > >                                         dataTable.setText( i, 2, new
> > > Date( rs.getFieldAsLong
> > > > ( 1 ) ).toString() );
> > > >                                 }
> > > >                                 else
> > > >                                 {
> > > >                                         db.execute( "DELETE FROM
> user" );
> > > >                                 }
> > > >                         }
> > > >                         // If a phrase has been removed, clear the
> label.
> > > >                         for ( ; i <= NUM_SAVED_ROWS; i++ )
> > > >                         {
> > > >                                 for ( int j = 0; j <
> > > NUM_DATA_TABLE_COLUMNS; j++ )
> > > >                                 {
> >
> > ...
> >
> > read more ยป
> >
>

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