随机显示JList

Question

我有2 JList秒。一个列表包含房东对象，第二个Jlist应显示与房东一起列出的属性。

现在我的问题是，当我尝试这样做时，所有的房东和所有属性都会同时显示。

但我想要的是，当我选择一个特定的房东时，那个与房东相关的房产只能展示。

以下是我的代码：

package assignment2;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Iterator;

import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class LeaseDialog extends JDialog implements ActionListener, 
    ListSelectionListener{

    private MySystemGui owner;
    private JButton exit;
    //DefaultListModel<Landlord> UnleaseProperty;
    DefaultListModel<Landlord> UnleasePropertyLandlord;
    Iterator<Landlord> getLandlordIterator;
    JList<Landlord> landlordList;
    JTextArea jta;
    Iterator<Property> getPropertyIterator;
    DefaultListModel<Property> UnleaseProperty; 
    JList<Property> propertyList;

    public LeaseDialog(MySystemGui owner,String title,boolean moodal) {
        super(owner,title,moodal);
        this.owner=owner;
        this.add(LandlordListPanel());
        this.add(buttonsPanel(),"South");
        this.setSize(500,500);
        this.setLocation(200, 200);
        this.setVisible(true);                  
    }

    private JPanel LandlordListPanel() {
        JPanel llp = new JPanel();

        UnleasePropertyLandlord = new DefaultListModel<Landlord>();
        UnleaseProperty = new DefaultListModel<Property>();
        getLandlordIterator = this.owner.getRealEstate().getLandlords().iterator();

        while(this.getLandlordIterator.hasNext()) {
            Landlord present = this.getLandlordIterator.next();
            System.out.println("The landlord is "+present.toString());
            getPropertyIterator = present.getPropertiesIterator();
            while(getPropertyIterator.hasNext()){
                Property presentProperty= getPropertyIterator.next();
                System.out.println("The property is "+presentProperty.toString());
                if(presentProperty.isLeased()==false  && 
                    !(UnleasePropertyLandlord.contains(present)) ){                     
                    UnleasePropertyLandlord.addElement(present);
                    //UnleaseProperty.addElement(presentProperty);
                }
                //else if(presentProperty.isLeased()==false){
                    //UnleaseProperty.addElement(presentProperty);
                //}
            }
        }

        landlordList = new JList<Landlord>(UnleasePropertyLandlord);
        landlordList.setVisibleRowCount(4);
        landlordList.addListSelectionListener(this);
        llp.add(new JScrollPane(landlordList));
        propertyList = new JList<Property>(UnleaseProperty);
        propertyList.setVisibleRowCount(4);
        propertyList.addListSelectionListener(this);
        llp.add(new JScrollPane(propertyList));

        jta = new JTextArea(10,30);
        jta.setEditable(false);
        llp.add(new JScrollPane(jta));

        return llp;         
    }

    private JPanel buttonsPanel(){
        JPanel button = new JPanel();
        exit = new JButton("Exit");
        exit.addActionListener(this);
        button.add(exit);
        return button;
    }

    public void actionPerformed(ActionEvent r){
        switch (r.getActionCommand()) {
            case "Exit":
                this.dispose();
        }
    }

    public void valueChanged(ListSelectionEvent lease){         
        if (lease.getSource()==UnleasePropertyLandlord){
            Landlord l = landlordList.getSelectedValue();
            Iterator <Property> pr = l.getPropertiesIterator();
            while (pr.hasNext()){
                Property presentProperty= pr.next();
                System.out.println("The property is "+presentProperty.toString());
                if (presentProperty.isLeased()==false){

                    UnleaseProperty.addElement(presentProperty);
                }
            }
            propertyList.setSelectedValue(UnleaseProperty, true);               
        }               
    }  
}