如何让Jcombox长度自适应列表框值

package com.macquarie.eqm.quantum.holding.gui;
import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
public class aaa {
public static void main(String[] args) {
class myCombo extends JComboBox {
public myCombo() {
super();
setUI(new myComboUI());
} //end of default constructor
class myComboUI extends BasicComboBoxUI {
protected ComboPopup createPopup() {
BasicComboPopup popup = new BasicComboPopup(comboBox) {
protected JScrollPane createScroller() {
return new JScrollPane(list,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.
HORIZONTAL_SCROLLBAR_AS_NEEDED);
} //end of method createScroller
};
return popup;
} //end of method createPopup
} //end of inner class myComboUI
}
JFrame aFrame = new JFrame();
myCombo JComboBox1 = new myCombo();
JComboBox1.setPreferredSize(new Dimension(20, 20));
JComboBox1.setMaximumSize(new Dimension(30, 20));
// String[] aArr = {"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
// "BBAAAAAAAAAAA",
// "CCCCC",
// "DDDDDDDDDDDDD",
// "EEEEEEEEEEEE",
// "FFFFFFFFFFFFFFFFFFFFFFFFFFFF",
// "GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG",
// "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
// "BBAAAAAAAAAAA",
// "CCCCC", "DDDDDDDDDDDDD",
// "EEEEEEEEEEEE",
// "FFFFFFFFFFFFFFFFFFFFFFFFFFFF",
// "GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG"};
for (int i = 0; i < aArr.length; i)
JComboBox1.addItem(aArr[i]);
aFrame.getContentPane().add(JComboBox1);
aFrame.getContentPane().setSize(100, 100);
aFrame.pack();
aFrame.setVisible(true);
} }
}
}
}
}
}
}