在java中,import java.awt.*里面的组件干什么用的?

//初始化程序 public void init(){//制作界面容器 Container contentPane=getContentPane(); contentPane.setLayout(new FlowLayout()); contentPane.add(button,BorderLayout.CENTER);//选择框chooser.setPreviewPanel(new PreviewPanel());//事件监听button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e){if(dialog==null) dialog=JColorChooser.createDialog(null,"pick a color",false,chooser,null,null); dialog.setVisible(true);}});}}package cn.com.dang; import java.awt.Dimension; import java.awt.Graphics; import javax.swing.BorderFactory; import javax.swing.JPanel; //制作预览面版