Java 进度条的实现源码，通过本例你可以学习到如何设置进度条启动时可显示的字符串，设置进度条边框，将进度条加入内容窗格中，设置加载条的显示位置等知识技巧。-The progress of implementation of Java source code, through the example you can learn how to set the string to display the progress bar start