一种可能性。您可以使用 JTextArea.append（String）方法：

  JTextArea textArea = new JTextArea 
 textArea.append（Your new String）; 
 

来自JavaDoc：

将给定的文本附加到文档的末尾。

请注意，您必须自己添加换行符，例如

  textArea.append（Your new String\\\
）;  



$ p  $ p> 

b $ b

如果您想要一个真正的自制控制台，请查看 ***a 或 JLine 。

How does one add text/commands (like in console) into JTextArea?

Or, more specifically, how can I add a JTextArea as console in my FTP program and add commands like C:\tmp\ -list with non-editable text added earlier?

Of course there is a possibility. You can use the JTextArea.append(String) method for this:

JTextArea textArea = new JTextArea();
textArea.append("Your new String");

From JavaDoc:

Appends the given text to the end of the document.

Take care that you have to add line breaks by yourself like

textArea.append("Your new String\n");

if you want to add a new line to the end.

If you want to have a real selfmade console, look for example at ***a or JLine.