java bean消息驅動

import java.awt.*;
import java.awt.event.*;
import java.io.Serializable;
import javax.swing.*;
import java.beans.*;
public class Loan extends JPanel implements ActionListener
{
protected PropertyChangeSupport changes=new PropertyChangeSupport(this);
private String loanType=new String("Personal Loan");
public void setLoanType(String temp)
{
String old=new String();
old=loanType;
loanType=temp;
changes.firePropertyChange("loanType",old,temp);
}
public String getLoanType()
{
return loanType;
}
JLabel lid,ltype;
JTextField tid,ttype;
JButton submit;
public Loan()
{
lid=new JLabel("Enter Loan Id:");
tid=new JTextField(8);
ltype=new JLabel("Loan Type:");
ttype=new JTextField(15);
submit=new JButton("ADD NEW LOAN");
setLayout(new GridLayout(3,2));
add(lid);add(tid);
add(ltype);add(ttype);
submit.addActionListener(this);
add(submit);
}
public void actionPerformed(ActionEvent evt)
{
Object obj=evt.getSource();
if(obj==
//Loan.java
/* This class contains the User Interface that Earnest Bank uses to add new loan types to the database. Whenever a new loan type is added, a property change event is generated */
submit
AN>)
setLoanType(ttype.getText());
}　　
public void addPropertyChangeListener(PropertyChangeListener l)
{
changes.addPropertyChangeListener(l);
}
public void removePropertyChangeListener(PropertyChangeListener l)
{
changes.removePropertyChangeListener(l);
}
}
//CustomerLoan.java
/* The following class is used by Earnest Bank to accept the details of customers who take loans. Whenever a new loan type is added to the database, the loan type should be
made available to the user.
/* This class traps the property change event generated by the Loan class and adds the new loan type to its loan type combo box. */
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
public class CustomerLoan implements PropertyChangeListener
{
　　static JFrame frameObj;
　　JPanel mp,chp1, Mpane;
　　Loan lp;
　　BoxLayout bl;
　　JLabel lcname,lctype;
　　JTextField tcname;
　　JComboBox tctype;
　　public CustomerLoan()
　　{
　　　　mp=new JPanel();
　　　　chp1=new JPanel();
　　　　Mpane=new JPanel();
　　　　lp=new Loan();
　　　　//bl=new BoxLayout(mp,BoxLayout.Y_AXIS);
　　　　//bl.addLayoutComponent(new String("Loan Panel"),lp);
　　　　//bl.addLayoutComponent(new String("Customer Panel"),chp1);
　　　　Mpane.setLayout(new FlowLayout());
　　　　Mpane.add(lp);
　　　　Mpane.add(chp1);
　　　　frameObj.getContentPane().add(Mpane);

　　　　lcname=new JLabel("Customer Name:");
　　　　lctype=new JLabel("Type of Loan taken:");
　　　　tcname=new JTextField(6);
　　　　tctype=new JComboBox();
　　　　tctype.addItem(lp.AN>getLoanType());
　　　　chp1.setLayout(new GridLayout(2,2));
　　　　chp1.add(lcname);
　　　　chp1.add(tcname);
　　　　chp1.add(lctype);
　　　　chp1.add(tctype);
　　　　lp.addPropertyChangeListener(this);
　　}
　　public void propertyChange(PropertyChangeEvent pcevent)
　　{
　　　　System.out.println("propertyChange was call");
　　　　tctype.addItem(pcevent.getNewValue());
　　}
　　public static void main(String args[])
　　{
　　　　frameObj=new JFrame("Loan Frame");
　　　　new CustomerLoan();
　　　　frameObj.setSize(400,400);
　　　　frameObj.setVisible(true);
　　}
}