编辑代码

class Main {
	public static void main(String[] args) {
        //JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。
		String strTest1 = "kafo";
        String strTest2 = "kafo.";
        String strTest3 = "kako.google";
        String strTest4 = "google";
        System.out.println(getChannelIdPrefix(strTest1));
        System.out.println(getChannelIdPrefix(strTest2));
        System.out.println(getChannelIdPrefix(strTest3));
         System.out.println(getChannelIdPrefix(strTest4));
	}

    public static String getChannelIdPrefix(String channelId){
        /*if(StringUtils.isNotBlank(channelId)){

		}*/
        String[] strArray = channelId.split("\\.");
        return strArray[0];
    }
}