import java.awt.Color;
import java.awt.Component;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;import javax.swing.DefaultComboBoxModel;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JList;public class JComboBox4ItemWidth extends JComboBox {private static final long serialVersionUID = 1L;private Map<String, String> antFactory_value_displayName4toolTipText;private Map<String, String> antFactory_value_displayName4dispaly = new HashMap<String, String>();public JComboBox4ItemWidth() {this.setRenderer(new ListCellRendererImpl());this.addItemListener(new ItemListenerImpl());this.setBackground(Color.WHITE);}public void setModelData(Object antFactory_value_displayName) {this.antFactory_value_displayName4toolTipText = (Map<String, String>) antFactory_value_displayName;Set<Entry<String, String>> antFactorys = this.antFactory_value_displayName4toolTipText.entrySet();DefaultComboBoxModel model = new DefaultComboBoxModel();for (Entry<String, String> antFactory : antFactorys) {antFactory_value_displayName4dispaly.put(antFactory.getKey(), format(antFactory.getValue()));model.addElement(antFactory.getKey());}this.setModel(model);}private String format(String displayValue) {if (displayValue.length() > 9) {displayValue = displayValue.substring(0, 6) + "...";}return displayValue;}public void setMoValue(Object value) {if (value != null && value.toString().trim().length() > 0) {this.setSelectedItem(value.toString());this.setToolTipText(getToolTipText4Display(value));} else {this.setSelectedIndex(-1); // 若从服务端得到的值是空，则界面显示空this.setToolTipText("");}}public Object getMoValue() {Object value = this.getSelectedItem();if (value != null && value.toString().trim().length() == 0) {value = "";}return value;}public String getDisplayValue(Object antFacotryValue) {String displayValue = this.antFactory_value_displayName4dispaly.get((String) antFacotryValue);return displayValue == null ? " " : displayValue;// 为空是需要空格，下拉选项才可显示出空值选项
    }public String getToolTipText4Display(Object antFacotryValue) {String displayValue = this.antFactory_value_displayName4toolTipText.get(antFacotryValue.toString());return displayValue == null ? " " : displayValue;// 为空是需要空格，下拉选项才可显示出空值选项
    }class ListCellRendererImpl extends DefaultListCellRenderer {private static final long serialVersionUID = -6671159080681655776L;public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {String display = getDisplayValue(value);JComponent comp = (JComponent) super.getListCellRendererComponent(list, display, index, isSelected, cellHasFocus);comp.setToolTipText(getToolTipText4Display(value));return comp;}}class ItemListenerImpl implements ItemListener {@Overridepublic void itemStateChanged(ItemEvent e) {setToolTipText(getToolTipText4Display(getSelectedItem()));}}}