> Now I'm wondering what's the longest class name out there...

The longest class names I remember are in the Java Development Kit (JDK) version 1.6, under the Swing+Nimbus namespace:

  com
  └─sun
    └─java
      └─swing
        └─plaf
          └─nimbus
            ├─...
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneCloseButtonPainter.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneCloseButtonWindowNotFocusedState.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneIconifyButtonPainter.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneIconifyButtonWindowNotFocusedState.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonPainter.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonWindowMaximizedState.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonWindowNotFocusedState.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMenuButtonPainter.java
            ├─InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMenuButtonWindowNotFocusedState.java
            ├─InternalFrameInternalFrameTitlePanePainter.java
            ├─InternalFrameInternalFrameTitlePaneWindowFocusedState.java
            └─...

There were threads in 2012 about them:

• https://news.ycombinator.com/item?id=4549685

• https://news.ycombinator.com/item?id=4770861

Someone copied the code in this repository: https://github.com/zxiaofan/JDK/tree/master/JDK1.6-Java%20SE...