实验10.面向对象设计(一).docx

实验报告实验序号：10实验项目名称：面向对象设计（一）学号姓名专业、班实验地点指导教师实验时间一、实验目的l 掌握按钮组件的编程方法l 掌握类的设计、静态方法、静态变量的概念和使用方法二、实验条件l 硬件要求：CPU PII 以上，64M 内存，100M 硬盘空间。l 软件要求：Windows98/Me/XP/NT/2000，IE 5 以上。l 开发环境：JDK1.6.0_10, NotePad或者EditPlus。三、实验内容与步骤Adding Buttons to StyleOptions.java下面的文件，StyleOptions.java和StyleOptionsPanel.java分别来自于教材例子5.22和5.23，并作了轻微改动，该程序展示了复选框和ItermListeners的用法。本练习要求读者添加三个单选按钮，使用户能够选择三种字体大小。添加单选按钮的方法参考教材例子5.25。按照以下步骤执行：1. 声明small、medium和large三个JRadioButton类型的对象。2. 对三个对象进行实例化，其标签名称分别为“Small Font”，“Medium Font”和“Large Font”。将large字体实例化为true。将按钮背景颜色设置为青色（cyan）。3. 实例化一个button group对象，并将单选按钮添加进来。4. 为单选按钮添加监听器代码。fontSize变量的值：small为12号字体，medium为24号字体，large为36号字体。然后调用saying对象的setFont方法来设置字体。（注意：不要增加新的监听器，而是使用当前的ItemListener。）5. 在StyleOptionsPanel()中为每个按钮对象添加ItemListener对象，并将按钮装载到面板。6. 编译程序。注意字体的改变将使复选框和按钮重新排列。后面的章节将介绍更多相关知识。实验运行结果： StyleOptions代码：/*/ StyleOptions.java Author: Lewis/Loftus/ Demonstrates the use of check boxes./*import javax.swing.JFrame;public class StyleOptions /- / Creates and presents the program frame. /- public static void main(String args) JFrame frame = new JFrame (Style Options); frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE); StyleOptionsPanel panel = new StyleOptionsPanel(); frame.getContentPane().add (panel); frame.pack(); frame.setVisible(true); StyleOptionsPanel代码：/*/ StyleOptionsPanel.java Author: Lewis/Loftus/ Demonstrates the use of check boxes./*import javax.swing.*;import java.awt.*;import java.awt.event.*;public class StyleOptionsPanel extends JPanel private int fontSize = 36; private int style = Font.PLAIN; private JLabel saying; private JCheckBox bold, italic; private JRadioButton small,medium,large; /- / Sets up a panel with a label and some check boxes that / control the style of the labels font. /- public StyleOptionsPanel() small = new JRadioButton(Small Font); small.setBackground(Color.cyan); medium = new JRadioButton(Medium Font); medium.setBackground(Color.cyan); large = new JRadioButton(Large Font,true); large.setBackground(Color.cyan); ButtonGroup group = new ButtonGroup(); group.add(small); group.add(medium); group.add(large); saying = new JLabel (Say it with style!); saying.setFont (new Font (Helvetica, style, fontSize); bold = new JCheckBox (Bold); bold.setBackground (Color.cyan); italic = new JCheckBox (Italic); italic.setBackground (Color.cyan); StyleListener listener = new StyleListener(); bold.addItemListener (listener); italic.addItemListener (listener); small.addItemListener(listener); medium.addItemListener(listener); large.addItemListener(listener); add (saying); add (bold); add (italic); add (small); add (medium); add (large); setBackground (Color.cyan); setPreferredSize (new Dimension(300, 100); /*/ Represents the listener for both check boxes./* private class StyleListener implements ItemListener /- / Updates the style of the label font style. /- public void itemStateChanged (ItemEvent event) style = Font.PLAIN; if (bold.isSelected() style = Font.BOLD; if (italic.isSelected() style += Font.ITALIC; if (small.isSelected() fontSize=12; else if (medium.isSelected() fontSize=24; else if (large.isSelected() fontSize=36; saying.setFont (new Font (Helvetica, style, fontSize); Opening and Closing AccountsAccount.java是一个简单的银行账户类，提供了取款，存款，获取余额与账号等方法，并返回一个关于账户的字符串描述信息，修改该类，使其构造器创建一个随机账号。保存这个类到本地磁盘，并修改代码：1. 假设银行希望监控现有的账户的数量a) 声明一个私有静态整型变量numAccount用于保存该值（该变量自动被初始化为0）。b) 修改构造器代码，一旦创建一个银行账户，该变量就自增一次。c) 添加静态方法numAccounts，返回账户总数。由于该值为静态，它的信息与任何专门的账户都不相关。d) TestAccounts.java创建了一个预先定义数目的银行账号，使用numAccounts方法返回创建了的账号的数目。将其保存至本地磁盘，运行并查看结果。2. 添加一个方法void close()至Account类。该方法通过附加一个“CLOSED”至账户姓名的尾部来关闭一个账户，并将余额设置为0，保持账户号码不变，同时更新当前的账户数量。3. 添加一个静态方法Account consolidate(Account acct1, Account acct2)至Account类，该方法创建一个新的账户，该账户余额是acct1与acct2之和，然后关闭acct1和acct2，然后返回该账户。注意两个重要的规则：l 只有相同用户姓名的账户才能够被consolidated（两个账户的户主名称为同一人）。新的账户的户主名称保持不变，但是会被赋予一个新的账户号码。l 两个具有相同账户号码的账户不能够被consolidated。在创建一个新账户之前检查这些条件。如果不满足任何一个条件，就不要创建新账户，或者关闭旧账户，打印一条提示信息，并返回一个空值。4. 编写一个测试程序，提示用户输入3个名字，为每一个人创建一个账户，初始化余额为100元。打印三个账户，关闭第一个，然后consolidate第二个和第三个账户。再次打印信息，包括被consolidated的账户。实验运行结果：TestAccounts代码：*/ TestAccounts.java/ Use Account class to create and manage Sally and Joes/ bank accounts/ *import java.util.Scanner;public class TestAccountspublic static void main(String args) Scanner scan = new Scanner(System.in); System.out.println(please input a account:); Account acct1 = new Account(scan.nextDouble(),scan.next(),scan.nextLong(); System.out.println(please input another account:); Account acct2 = new Account(scan.nextDouble(),scan.next(),scan.nextLong(); System.out.println(please input another account:); Account acct3 = new Account(scan.nextDouble(),scan.next(),scan.nextLong(); System.out.println(); System.out.println(acct1.toString()+n); System.out.println(acct2.toString()+n); System.out.println(acct3.toString()+n); System.out.println(There are + Account.numAccounts() + accounts); acct1.Close(); System.out.println(); System.out.println(* New Account *); System.out.println(acct1.toString()+n); System.out.println(acct2.toString()+n); System.out.println(acct3.toString()+n); System.out.println(Now There are + Account.numAccounts() + accounts); Account acct4 = Account.consolidate(acct2,acct3); System.out.println(); System.out.println(acct4.toString(); System.out.println(There are + Account.numAccounts() + accounts); Account代码：/*/ Account.java/ A bank account class with methods to deposit to, withdraw from,/ change the name on, charge a fee to, and print a summary of the account./*public class Account private double balance; private String name; private long acctNum; static int numAccount=0; /-/Constructor - initializes balance, owner, and account number/- public Account(double initBal, String owner, long number) balance = initBal; name = owner; acctNum = number; numAccount+; public static int numAccounts() return numAccount; /-/ Checks to see if balance is sufficient for withdrawal./ If so, decrements balance by amount; if not, prints message./- public void withdraw(double amount) if (balance = amount) balance -= amount; else System.out.println(Insufficient funds); /-/ Adds deposit amount to balance./52 Chapter 4: Writing Classes/- public void deposit(double amount) balance += amount; /-/ Returns balance./- public double getBalance() return balance; /-/ Returns a string containing the name, account number, and balance./- public String toString() return(Name: + name + nBalance： + balance + nAc