class People{ protected double weight,height; public void speakHello() { System.out.println("yayawawa"); } public void averageHeight() { height=173; System.out.println("average height:"+height); } public void averageWeight() { weight=70; System.out.println("average weight:"+weight); } }class ChinaPeople extends People{ public void speakHello() { System.out.println("你好，吃饭了吗？"); } public void averageHeight() { height=173.0; System.out.println("中国人的average height:"+height); } public void averageWeight() { weight=67.34; System.out.println("中国人的average weight:"+weight); } public void chinaGongfu() { System.out.println("坐如钟，站如松，睡如弓"); }}class AmericanPeople extends People{ public void speakHello() { System.out.println("How do you do"); } public void averageHeight() { height=188.0; System.out.println("American average height:"+height); } public void averageWeight() { weight=80.23; System.out.println("American average weight:"+weight); } public void americanBoxing() { System.out.println("直拳，钩拳"); }}class BeijingPeople extends ChinaPeople{ public void speakHello() { System.out.println("您好"); } public void aversageHeight() { height=167.0; System.out.println("北京人的average height:"+height); } public void averageWeight() { weight=68.5; System.out.println("北京人的average weight:"+weight); } public void beijingOpera() { System.out.println("京剧术语"); }}public class Example{ public static void main(String args[]) { ChinaPeople chinaPeople=new ChinaPeople(); AmericanPeople americaPeople=new AmericanPeople(); BeijingPeople beijingPeople=new BeijingPeople(); chinaPeople.speakHello(); americanPeople.speakHello(); beijingPeople.speakHello(); americanPeople.averageHeight(); beijingPeople.averageHeight(); chinaPeople.averageWeight(); americanPeople.averageWeight(); beijingPeople.averageWeight(); chinaPeople.chinaGongfu(); americaPeople.americanBoxing(); beijingPeople.beijingOpera(); beijingPeople.chinaGongfu(); }}import java.awt.*;import java.awt.event.*;public class ComputerFrame extends Frame implements ActionListener{ TextField textOne,textTwo,textResult; Button getProblem,giveAnwser; Label operatorLabel,message; Teacher teacher; ComputerFrame(String s) { super(s); teacher=new Teacher(); setLayout(new FlowLayout()); textOne=new TextField(10); textTwo=new TextField(10); textResult=new TextField(10); operatorLabel=new Label("+"); message=new Label("你还没有回答呢"); getProblem=new Button("获取题目"); giveAnwser=new Button("确认答案"); add(getProblem); add(textOne); add(operatorLabel); add(textTwo); add(new Label("=")); add(textResult); add(giveAnwser); add(message); textResult.requestFocus(); textOne.setEditable(false); textTwo.setEditable(false); getProblem.addActionListener(this); giveAnwser.addActionListener(this); textResult.addActionListener(this); setBounds(100,100,450,100); setVisible(true); validate(); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } } ); } public void actionPerformed(ActionEvent e) { if(e.getSource()==getProblem) { int number1=teacher.giveNumberOne(100); int number2=teacher.giveNumberTwo(100); String operator=teacher.giveOperator(); textOne.setText(""+number1); textTwo.setText(""+number2); operatorLabel.setText(operator); message.setText("请回答"); textResult.setText(null); } if(e.getSource()==giveAnwser) { String answer=textResult.getText(); try{ int result=Integer.parseInt(answer); if(teacher.getRight(result)==true) { message.setText("你回答正确"); } else { message.setText("你回答错误"); } } catch(NumberFormatException ex) { message.setText("请输入数字字符"); } } textResult.requestFocus(); validate(); }}public class Teacher{ int numberOne,numberTwo; String operator=" "; boolean right; public int giveNumberOne(int n) { numberOne=(int)(Math.random()*n)+1; return numberOne; } public int giveNumberTwo(int n) { numberTwo=(int)(Math.random()*n)+1; return numberTwo; } public String giveOperator() { double d=Math.random(); if(d>=0.5) operator="+"; else operator="-"; return operator; } public boolean getRight(int answer) { if(operator.equals("+")) { if(answer==numberOne+numberTwo) right=true; else right=false; } else if(operator.equals("-")) { if(answer==numberOne-numberTwo) right=true; else right=false; } return right; }}public class MainClass{ public static void main(String args[]) { ComputerFrame frame; frame=new ComputerFrame("算术测试"); }}WordThread.javaimport java.awt.*;public class WordThread extends Thread{ char word; int k=19968; Label com; WordThread(Label com) { =com; } public void run() { k=19968; while(true) { word=(char)k; com.setText(""+word); try{ sleep(6000); } catch(InterruptedException e){} k++; if(k>=29968) k=19968; } } }ThreadFrame.javaimport java.awt.*;import java.awt.event.*;public class ThreadFrame extends Frame implements ActionListener{ Label wordLabel; Button button; TextField inputText,scoreText; WordThread giveWord; int score=0; ThreadFrame() { wordLabel=new Label(" ",Label.CENTER); wordLabel.setFont(new Font("",Font.BOLD,72)); button=new Button("开始"); inputText=new TextField(3); scoreText=new TextField(5); scoreText.setEditable(false); giveWord=new WordThread(wordLabel); button.addActionListener(this); inputText.addActionListener(this); add(button,BorderLayout.NORTH); add(wordLabel,BorderLayout.CENTER); Panel southP=new Panel(); southP.add(new Label("输入标签所显示的汉字后回车:")); southP.add(inputText); southP.add(scoreText); add(southP,BorderLayout.SOUTH); setBounds(100,100,350,180); setVisible(true); validate(); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } } ); } public void actionPerformed(ActionEvent e) { if(e.getSource()==button) { if(!(giveWord.isAlive())) //giveWord调用方法isAlive() { giveWord=new WordThread(wordLabel); } try { giveWord.start(); } catch(Exception exe){} } else if(e.getSource()==inputText) { if(inputText.getText().equals(wordLabel.getText())) { score++; } scoreText.setText("得分:"+score); inputText.setText(null); } }}WordThread.javapublic class ThreadWordMainClass{ public static void main(String args[]) { new ThreadFrame(); }ReadZipFile.javaimport java.io.*;import java.util.zip.*;public class ReadZipFile{ public static void main(String args[]) { File f=new File("book.zip"); File dir=new File("Book"); byte b[]=new byte[100]; dir.mkdir(); try { ZipInputStream in=new ZipInputStream(new FileInputStream(f)); ZipEntry zipEntry=null; while((zipEntry=in.getNextEntry())!=null) { File file=new File(dir,zipEntry.getName()); FileOutputStream out=new FileOutputStream(file); int n=-1; System.out.println(file.getAbsolutePath()+"的内容："); while((n=in.read(b,0,100))!=-1) { String str=new String(b,0,n); System.out.println(str); out.write(b,0,n); } out.close(); } in.close(); } catch(IOException ee) { System.out.println(ee); } }}ReadFile.javaimport java.awt.*;import java.awt.event.*;import .*;import java.io.*;public class ReadURLSource{ public static void main(String args[]) { new NetWin(); }}class NetWin extends Frame implements ActionListener,Runnable{ Button button; URL url; TextField text; TextArea area; byte b[]=new byte[118]; Thread thread; NetWin() { text=new TextField(20); area=new TextArea(12,12); button=new Button("确定"); button.addActionListener(this); thread=new Thread(this); Panel p=new Panel(); p.add(new Label("输入网址:")); p.add(text); p.add(button); add(area,BorderLayout.CENTER); add(p,BorderLayout.NORTH); setBounds(60,60,360,300); setVisible(true); validate(); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); } public void actionPerformed(ActionEvent e) { if(!(thread.isAlive())) thread=new Thread(this); try{ thread.start(); } catch(Exception ee) { text.setText("我正在读取"+url); } } public void run() { try { int n=-1; area.setText(null); String name=text.getText().trim(); url=new URL(name); String hostName= url.getHost(); int urlPortNumber= url.getPort(); String fileName= url.getFile(); InputStream in= url.openStream(); area.append("\n主机:"+hostName+"端口:"+urlPortNumber+"包含的文件名字:"+fileName); area.append("\n文件的内容如下:"); while((n=in.read(b))!=-1) { String s=new String(b,0,n); area.append(s); } } catch(MalformedURLException e1) { text.setText(""+e1); return; } catch(IOException e1) { text.setText(""+e1); return; } }import java.util.*;public class Example13_1{ public static void main(String args[]) { List list=new LinkedList(); list.add("is"); list.add("a"); int number=list.size(); System.out.println("现在链表中有"+number+"个节点:"); for(int i=0;i