Java面向对象程序设计复习题附答案解析

protected Student next; static Student list;

Student (String name, char sex, int chinese, int english) { this.name=name; this.sex=sex; this.chinese=chinese; this.english=english; this.next=list; list=this; }

static void print() { Student friend=list; if (friend==null)

System.out.println(\ else { do{

System.out.println(friend.toString()); friend=friend.next; }while(friend!=null); } }

public String toString() {

return new String(name+\ } }

7. 写出以下程序的功能。

import java.io.*; public class TestFile {

public static void main(String args[]) throws Exception {

BufferedReader br = new BufferedReader(

new InputStreamReader(System.in));

BufferedWriter bw = new BufferedWriter(new FileWriter(“input.txt\ String s; while (true)

{

System.out.print(\请输入一个字符串： \ System.out.flush(); s=br.readLine(); if (s.length()==0) break; bw.write(s); bw.newLine(); } bw.close(); } }

8. 阅读以下程序，写出输出结果。

class Animal { Animal() {

System.out.print (\ \ } }

public class Dog extends Animal { Dog() {

System.out.print (\ }

public static void main(String[] args) { Dog snoppy= new Dog(); }

}

四、程序填空题

1.以下程序是一个算术测试小软件，用来训练小学生的算术能力。程序有3个类组成，其中Teacher对象充当监视器，负责给出算术题目，并判断回答者的答案是否正确。ComputerFrame对象负责为算术题目提供视图，比如用户可以通过ComputerFrame对象提供的GUI界面看到题目，并通过该GUI界面给出题目的答案；MailClass是软件的主类。

程序运行效果如下图所示。

仔细阅读程序代码，请按模板要求，在【代码】处填写合适的Java程序代码。

MainClass.java

public class MainClass {

public static void main(String args[]) { ComputerFrame frame;

frame=new ComputerFrame(); frame.setTitle(\算术测试\

frame.setBounds(100,100,650,180); } }

ComputerFrame.java

import java.awt.*;

import java.awt.event.*; import javax.swing.*;

public class ComputerFrame extends JFrame { JMenuBar menubar;

JMenu choiceGrade; //选择级别的菜单 JMenuItem grade1,grade2;

JTextField textOne,textTwo,textResult; JButton getProblem,giveAnwser; JLabel operatorLabel,message; Teacher teacherZhang; ComputerFrame() {

teacherZhang=new Teacher(); teacherZhang.setMaxInteger(20);

setLayout(【代码1】_new FlowLayout()________________________________); //设置ComputerFrame的布局为FlowLayout布局

menubar = new JMenuBar();

choiceGrade = new JMenu(\选择级别\ grade1 = new JMenuItem(\幼儿级别\ grade2 = new JMenuItem(\儿童级别\

grade1.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) { teacherZhang.setMaxInteger(10); } });

grade2.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) { teacherZhang.setMaxInteger(50); } }); choiceGrade.add(grade1); choiceGrade.add(grade2); menubar.add(choiceGrade); setJMenuBar(menubar);

【代码1】__ textOne=new JTextField(5);_________________________________ //创建textOne,其可见字符长是5 textTwo=new JTextField(5); textResult=new JTextField(5); operatorLabel=new JLabel(\

operatorLabel.setFont(new Font(\ message=new JLabel(\你还没有回答呢\ getProblem=new JButton(\获取题目\ giveAnwser=new JButton(\确认答案\ add(getProblem); add(textOne);

add(operatorLabel); add(textTwo);

add(new JLabel(\ add(textResult); add(giveAnwser); add(message);

textResult.requestFocus(); textOne.setEditable(false); textTwo.setEditable(false);

getProblem.setActionCommand(\ textResult.setActionCommand(\ giveAnwser.setActionCommand(\

teacherZhang.setJTextField(textOne,textTwo,textResult); teacherZhang.setJLabel(operatorLabel,message);

【代码2】_______ getProblem.addActionListener(teacherZhang); ____________ //将teacherZhang注册为getProblem的ActionEvent事件监视器