哪个事件选择了Java JTextArea中的文本触发器？(Which event a selection of text trigger in Java JTextArea?)

我想监视文本的选择到JTextArea。 我不知道选择的文本会触发什么事件。

我只想在JTextArea中选择一些文本时启用一些菜单项，例如菜单中的复制和剪切选项。 我应该监控什么？

I want to monitor the selection of text into the a JTextArea. I don't know what event a selection of text triggers.

I just want to enable some of the menu items as soon as some text is selected out of the JTextArea like copy and cut options into the menu. What should I monitor for that?