JAVA中的Box.createVerticalStrut什么意思?

createVerticalStrut
public static Component createVerticalStrut(int height)Creates an invisible, fixed-height component. In a vertical box, you typically use this method to force a certain amount of space between two components. In a horizontal box, you might use this method to force the box to be at least the specified height. The invisible component has no width unless excess space is available, in which case it takes its share of available space, just like any other component that has no maximum width.

Parameters:
height - the height of the invisible component, in pixels >= 0
Returns:
the component

简单的说作用是 设的两个控件的垂直距离.