public function getContentType() {
		if (!isset($this->contentType)) {
			$numOfMatches = preg_match('/^([^;]*)/', $this->getHeader('Content-Type'), $matches);
			if ($numOfMatches) {
				$this->contentType = trim($matches[1]);
			} else {
				$this->contentType = '';
			}
		}
		return $this->contentType;
	}