It doesn’t take much Java development experience to learn firsthand what the NullPointerException is about. In fact, one person has highlighted dealing with this as the number one mistake Java ...

While Java is one of the most in-demand and widely used programming languages in the world, it is not without its detractors. Java is not a particularly beginner-friendly language and it is rife with ...

网上也有相关的提问：回答的一般是，控制指针错误，控制操作，有个空指针什么的，本人不太明白，请高手给点详细的提示。