为什么要导入javax.swing。*而不是java.swing。*
问题描述：
我不明白为什么在java中为少数导入包添加了x。是什么原因？不能只是 java.swing。* 和其他人一样 java.io。* ？
I did not understand why there is "x" appended to "java" for few of the import packages. What is the reason? Can't it be just java.swing.* like others java.io.*?
答
Swing最初是Java的扩展 - 一个可单独下载的库。它成为Java 1.2中主要JRE的一部分。如果一个单独的库声称一个java。*包，那将是奇怪的，因此目前的情况。还有很多其他扩展也有类似的故事。
Swing was originally an extension to Java - a separately downloadable library. It became part of the "main" JRE in Java 1.2. It would have been odd for a separate library to have claimed a java.* package, hence the current situation. There are plenty of other extensions which have a similar story.
The Wikipedia article on Swing has a bit more information on its history.