Bug 211175 ClassCastException thrown when implementing IReportItemQuery
When implementing IReportItemQuery's method, public IDataQueryDefinition[] createReportQueries(IDataQueryDefinition parent) throws BirtException, even if the impl method returns IDataQueryDefinition[], ClassCastException will be thrown during preview, the error log is as follows: java.lang.ClassCastException: [Lorg.eclipse.birt.data.engine.api.IDataQueryDefinition; at org.eclipse.birt.report.engine.executor.ExtendedGenerateExecutor.generateContent(ExtendedGenerateExecutor.java:91) at org.eclipse.birt.report.engine.executor.ExtendedGenerateExecutor.execute(ExtendedGenerateExecutor.java:72) at org.eclipse.birt.report.engine.executor.ExtendedItemExecutor.execute(ExtendedItemExecutor.java:60) at org.eclipse.birt.report.engine.internal.executor.dup.SuppressDuplicateItemExecutor.execute(SuppressDuplicateItemExecutor.java:42) If the method returns IBaseQueryDefinition[], it's ok. Look at the engine code, there's something wrong of class casting when generating content.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/presentation/LocalizedContentVisitor.java
return cell;
	}
	/**
	 * handle the data content.
	 * 
	 * @param data
	 *            data content object
	 */
	public Object visitData( IDataContent data, Object value )
	{
		handleOnRender( data );
		processData( data );
		return data;
	}
	/**
	 * process the data content
	 * 
	 * <li> localize the help text
	 * <li> format the value
	 * <li> handle it as it is an text.
	 * 
	 * @param data
	 *            data object
	 */
	protected void processData( IDataContent data )
	{
		String helpText = localize( data, data.getHelpKey( ), data.getHelpText( ) );
		data.setHelpText( helpText );
		String text = ""; 
		if ( data.getLabelKey( ) != null || data.getLabelText( ) != null )