The first step in learning Java is to install JDK, write a Hello World, "In fact, JDK's learning is not so simple, there are two questions about JDK, it is easy to have always plagued Java programmers: one is a classpath problem, in fact In principle, it is to figure out how JRE's ClassLoader loads Class; another problem is Package and Import issues, how to find the path problem of classes. Take all the two questions and clearly remove the biggest obstacles to learning Java and using JDK. It is recommended to look at Wang Sen's "Java Deep Adventures" and discuss these two issues.
