Bug 140542 label can't be displayed without resource file or unmatched key
Steps to reproduce: 1.New a report, add a lable with text "aaa" 2.Add a resource file for the report, set key to "key1", value to "actuate", apply the value to the label 3.Clear the resource file in Property Editor->General->Resource File (or change the key to "abc") 4.Preview the report Expected result: 1.Display label text "aaa" on preview or 2.Give a warning message to say resource file is not found or unmatched key Actual result: Nothing displays on preview
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/BundleHelper.java
}
		
		PropertyResourceBundle bundle = populateBundle( baseName
				+ ".properties" ); 
		if ( bundle != null )
			bundleHierarchy.add( bundle );
		return bundleHierarchy;
	}
	/**
	 * Populates a <code>ResourceBundle</code> for a input file.
	 * 
	 * @param file
	 *            a file binds to a message file.
	 * @return A <code>ResourceBundle</code> for a input file, return
	 *         <code>null</code> if the file doesn't exist or any exception
	 *         occurred during I/O reading.
	 */
	private PropertyResourceBundle populateBundle( String fileName )
	{
		assert fileName != null;
		InputStream is = null;
		try
		{
			URL inputURL = module.getSession( ).getResourceLocator( )
					.findResource( module.getModuleHandle( ), fileName, 0 );
			if ( inputURL == null )
				return null;
			is = inputURL.openStream( );
			PropertyResourceBundle bundle = new PropertyResourceBundle( is );
			is.close( );