Bug 207250 Check blank value for datetime type parameter from url.[0002][0705]
Description: Check blank value for datetime type parameter from url. Build number:2.3.0.v20071023 Steps to reproduce: 1. New a datetime parameter mydt,listbox, tick off isRequired. 2. Preview in external browser and add "&dt=" in url, press enter. Expected result: Error message to indicate blank value isn't allowed for this parameter. Actual result: No error message and blank value is accepted. I tried to new a jsp and use <birt:paramDef> to pass the blank value and the blank value is accepted,too. Error log:n/a
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/DataUtil.java
*/
	public static String trimString( String str )
	{
		if ( str == null )
			return ""; 
		return str.trim( );
	}
	/**
	 * Trim the end separator
	 * 
	 * @param path
	 * @return
	 */
	public static String trimSepEnd( String path )
	{
		path = trimString( path );
		if ( path.endsWith( File.separator ) )
		{
			path = path.substring( 0, path.length( ) - 1 );
		}
		return path;
	}
	/**
	 * Trim the end separator
	 * 
	 * @param path
	 * @return
	 */
	public static String trimSepFirst( String path )
	{