为了更好理解MVC一例

<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> 为了更好理解MVC,在这里我给出一个简单例子. 共有4个java类,你可以Run AccountFrame.java.

//AccountModel.java package com.newmodern.mvc; import java.util.*; public class AccountModel extends Observable{ private double dBalance; private String AccountID; public AccountModel(String AccountID, double dBalance){ this.AccountID = AccountID; this.dBalance = dBalance; } public void deposit(double dBalance){ this.dBalance =dBalance; setChanged(); notifyObservers(this); } public void substract(double dBalance){ this.dBalance-=dBalance; setChanged(); notifyObservers(this); } public double getBalance(){ return dBalance; } public void mynotifyObservers(){ setChanged(); notifyObservers(this); } }

//AccountView.java package com.newmodern.mvc; import java.util.*; import java.awt.*; public class AccountView implements Observer{ TextField txtBalance; AccountModel am; public AccountView (AccountModel am){ this.am = am; am.addObserver(this); txtBalance = new TextField(10); } public void update(Observable o,Object arg){ txtBalance.setText(String.valueOf(am.getBalance())); } public TextField getTextField(){ return txtBalance; } }

package com.newmodern.mvc; import java.awt.event.*; public class AccountController implements ActionListener{ AccountFrame accountFrame; public AccountController(AccountFrame af){ this.accountFrame = af; } public void actionPerformed(ActionEvent ae) { String sCommand = ae.getActionCommand(); if (sCommand.equals("deposit")){ System.out.println("Action: deposit"); accountFrame.am.deposit(accountFrame.getValue()); } else if(sCommand.equals("sub")){ System.out.println("Action: substract"); accountFrame.am.substract(accountFrame.getValue()); } } }

package com.newmodern.mvc; import java.awt.*; import java.awt.event.*; public class AccountFrame extends Frame { AccountController ac; AccountView av; AccountView av1; AccountModel am; TextField txtValue; Button btnDeposit; Button btnSub; public AccountFrame (String sTitle) { super(sTitle); addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent we){ dispose(); System.exit(0); } }); ac = new AccountController(this); am = new AccountModel(sTitle,0); av = new AccountView(am); av1 = new AccountView(am); setLayout(new GridLayout(4,2)); txtValue = new TextField(10); btnDeposit = new Button("deposit"); btnSub = new Button("sub"); add(new Label("value:")); add(txtValue); add(new Label("balance:")); add(av.getTextField()); add(new Label("balance1:")); add(av1.getTextField()); add(btnDeposit); add(btnSub); btnDeposit.addActionListener(ac); btnSub.addActionListener(ac); //setSize(200,200); pack(); show(); am.mynotifyObservers(); } public double getValue() throws NumberFormatException { double value = Double.parseDouble(txtValue.getText()); return value; } public static void main(String args[]) { String id = "100"; new AccountFrame(id); } }