What is the exact Java code snippet that you are using?
On Thu, May 7, 2009 at 10:10 PM, Evan Ruff <evan.r...@gmail.com> wrote:
>
> Vitali,
>
> I was just trying to match '?' in the SQL statement, such as:
>
> INSERT into users ( name, city ) VALUES( ?, ? )
>
> so I can mash up my own prepare SQL statement.
>
> Also, I can run the test on the android phone to see if that might be
> the problem.
>
> E
>
> On May 7, 4:36 pm, Vitali Lovich <vlov...@gmail.com> wrote:
> > 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 <evan.r...@gmail.com> 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 <vlov...@gmail.com> 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 <evan.r...@gmail.com>
> 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 <evan.r...@gmail.com> 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.
> > > > > > */
> >
> > ...
> >
> > read more ยป
> >
>
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