请问：addActionListener是什么意思，在哪个包中？

实现addActionListener方法的有以下这些组件
java.awt.Button.addActionListener(java.awt.event.ActionListener) 
java.awt.List.addActionListener(java.awt.event.ActionListener) 
java.awt.MenuItem.addActionListener(java.awt.event.ActionListener) 
java.awt.TextField.addActionListener(java.awt.event.ActionListener) 
javax.swing.AbstractButton.addActionListener(java.awt.event.ActionListener) 
javax.swing.ButtonModel.addActionListener(java.awt.event.ActionListener) 
javax.swing.ComboBoxEditor.addActionListener(java.awt.event.ActionListener) 
javax.swing.DefaultButtonModel.addActionListener(java.awt.event.ActionListener) 
javax.swing.JComboBox.addActionListener(java.awt.event.ActionListener) 
javax.swing.JFileChooser.addActionListener(java.awt.event.ActionListener) 
javax.swing.JTextField.addActionListener(java.awt.event.ActionListener) 
javax.swing.plaf.basic.BasicComboBoxEditor.addActionListener(java.awt.event.ActionListener) 
javax.swing.Timer.addActionListener(java.awt.event.ActionListener)
它做的事情是将监听器加入自己维护的一个列表，当做出一些修改时，调用加入的这些监听器的
actionPerformed(ActionEvent e)方法