上一章讲到自己开发的系统主类带着一个信息管理工已经到了可视的施工基地现场，那如何参与这个庞大的工程呢。其实平台给我们提供的地基启动类除了start方法外，还有一个init()方法,我们看官方的说明：

Life-cycle

The entry point for JavaFX applications is the Application class. The JavaFX runtime does the following, in order, whenever an application is launched:

1. Starts the JavaFX runtime, if not already started (see Platform.startup(Runnable) for more information)
2. Constructs an instance of the specified Application class
3. Calls the init() method
4. Calls the start(jav