android 关于选择图片，判断图片的类型

ContentResolver resolver = getContentResolver();
			String fileType = resolver.getType(selectedImage).trim().toLowerCase();
			if (!fileType.matches("^image/(jpg|png|jpeg)$")){
				dialog.cancel();
				ForresultActivity.this.finish();
				Utiltools.printE("选择照片是否是图片"+fileType.startsWith("image/jpg"));
				return;
			}
			cursor1.moveToFirst();