java菜鸟问题记录当遇到--started with null constructor

本人编写了一个小程序后报错显示：

IWAV0048I Java Bean ManagerTest started with null constructor

经查证后才知道：

That's not an error. That is simply a message to tell you that the Java Bean Application Launcher used the null constructor of your class to start it. That means your class was not a standard AWT/Swing subclass so it couldn't figure out a nicer way of starting it (like it would if it was a JFrame or a JPanel). We give this info because often when starting with the null constructor nothing visual happens and people get confused and don't realize it actually ran because the console would be empty. When you actually write your application with its own main and use your class then this message won't show because the code that produces it won't be in your application.

这个不是错误，是程序运行时没有入口，这不是一个application，只是一个Bean，而我的ManagerTest类是main函数，结果检查了一下是因为自己的mian拼错了

这是个极为低级的错误，但是找的时候也挺烦人的，希望有类似问题的同学可以尽快看到，共勉！！！