How does JAVA make JTextArea in JScrollPane automatically scroll to the last line?

1. To make the JTextArea with scrollbars, add the JTextArea object to the JScrollPane.

New // Create JTextArea Object Logarea.setwrapstyleword (true// line wrapping: Do not split the word logarea.setlinewrap ( true // Wrap Line // Add a vertical scroll bar to JTextArea New JScrollPane (Logarea,scrollpaneconstants.vertical_scrollbar_always,scrollpaneconstants.horizontal_scrollbar_ Never);

2. To enable JTextArea to automatically scroll to the last line when updating the content, you can manipulate the Jscrollbar.

StaticJscrollbar scrollbar=Logscroll.getverticalscrollbar ();//each time you need to add a string to JTextArea, call the following method
Private voidRefreshtextarea (String text) {logarea.append (text);
After updating Logarea, slightly delayed, otherwise the data obtained by Getmaximum () may not be the last maximum value, cannot scroll to the last line
        Try{Thread.Sleep (100); } Catch(Interruptedexception ex) {Logger.getlogger (testserver.class. GetName ()). log (Level.severe,NULL, ex);    } scrollbar.setvalue (Scrollbar.getmaximum ()); }

How does JAVA make JTextArea in JScrollPane automatically scroll to the last line?