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/extension/IReportItemGeneration.java
*/
	public abstract void init(IReportItemGenerationInfo info);
	/**
	 * passes a handle to the extended report item model to the extension
	 * 
	 * @deprecated implement #init(IReportItemGenerationInfo) instead
	 * @param modelHandle
	 *            a handle to the extended item model object
	 */
	public abstract void setModelObject( ExtendedItemHandle modelHandle );
	/**
	 * passes the class loader used to load user defined classes.
	 * 
	 * @deprecated implement #init(IReportItemGenerationInfo) instead
	 * @param loader
	 *            class loader used to load the classes
	 */
	public abstract void setApplicationClassLoader( ClassLoader loader );
	/**
	 * pass the script context to the report item.
	 * 
	 * @deprecated implement #init(IReportItemGenerationInfo) instead
	 * @param context
	 *            report context used by java-based script
	 */
	public abstract void setScriptContext( IReportContext context );
	/**
	 * pass the prepared query definition to extended item implementation, so
	 * that it can access data.
	 *