Bug 187162 [Regression]NPE throws out when open a dataset which reference datasource has no driver[07]
Description: NPE throws out when open a dataset which reference datasource has no driver[07] Build number: 2.2.0.v20070516-0630 Steps to reproduce: 1, open a dataset makesure the datasource has no driver 2, Close all the warning dialog and the dataset dialog 3, Check the error log Expected result: No NPE throws out Actual result: NPE throws out Error log: java.lang.NullPointerException at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.refreshPage(SQLDataSetEditorPage.java:1376) at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.initializeControl(SQLDataSetEditorPage.java:272) at org.eclipse.birt.report.data.oda.jdbc.ui.editors.SQLDataSetEditorPage.createPageCustomControl(SQLDataSetEditorPage.java:191) at org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage.createControl(DataSetWizardPage.java:123) at org.eclipse.datatools.connectivity.oda.design.internal.ui.DataSetEditorPageCore.createContents(DataSetEditorPageCore.java:73) at org.eclipse.jface.preference.PreferencePage.createControl(PreferencePage.java:233) at org.eclipse.birt.report.designer.data.ui.dataset.PropertyPageWrapper.createPageControl(PropertyPageWrapper.java:45) at org.eclipse.birt.report.designer.data.ui.property.PropertyNode.createPageControl(PropertyNode.java:238) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog.showPage(AbstractPropertyDialog.java:442) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog.showSelectionPage(AbstractPropertyDialog.java:346) at org.eclipse.birt.report.designer.data.ui.dataset.DataSetEditor.showSelectionPage(DataSetEditor.java:720) at org.eclipse.birt.report.designer.data.ui.property.AbstractPropertyDialog$2.run(AbstractPropertyDialog.java:304)
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
int numberOfTable;
				Preferences preferences = JdbcPlugin.getDefault( )
						.getPluginPreferences( );
				if ( preferences.contains( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA ) )
				{
					numberOfTable = preferences.getInt( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA );
				}
				else
				{
					numberOfTable = DateSetPreferencePage.DEFAULT_MAX_NUM_OF_TABLE_EACH_SCHEMA;
					preferences.setValue( DateSetPreferencePage.USER_MAX_NUM_OF_TABLE_EACH_SCHEMA,
							numberOfTable );
				}
				int count = 0;
				while ( tablesRs.next( ) && count < numberOfTable )
				{
					String tableName = tablesRs.getString( "TABLE_NAME" );
					String type = tablesRs.getString( "TABLE_TYPE" );
					if ( type.equalsIgnoreCase( "SYSTEM TABLE" ) )
						continue;
					
					
					int dbType = DbObject.TABLE_TYPE;
					if ( type.equalsIgnoreCase( "TABLE" ) )
					{
						image = tableImage;
						dbType = DbObject.TABLE_TYPE;
					}
					else if ( type.equalsIgnoreCase( "VIEW" ) )
					{