簡單的java源碼

1. 高分求兩個簡單的java設計源代碼

上面 wukun12同學寫的不錯，但我想還不能運行，並且還不太完善。我給個能運行的：（注意：文件名為：Test.java)

//要實現對象間的比較，就必須實現Comparable介面，它裡面有個compareTo方法
//Comparable最好使用泛型，這樣，無論是速度還是代碼量都會減少
@SuppressWarnings("unchecked")
class Student implements Comparable<Student>{

private String studentNo; //學號
private String studentName; //姓名
private double englishScore; //英語成績
private double computerScore; //計算機成績
private double mathScore; //數學成績
private double totalScore; //總成績

//空構造函數
public Student() {}

//構造函數
public Student(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
this.studentNo = studentNo;
this.studentName = studentName;
this.englishScore = englishSocre;
this.computerScore = computerScore;
this.mathScore = mathScore;
}

//計算總成績
public double sum() {

this.totalScore = englishScore+computerScore+mathScore;
return totalScore;
}

//計算評測成績
public double testScore() {

return sum()/3;
}

//實現compareTO方法
@Override
public int compareTo(Student student) {
double studentTotal = student.getTotalScore();
return totalScore==studentTotal?0:(totalScore>studentTotal?1:-1);
}

//重寫toString方法
public String toString(){
return "學號："+this.getStudentNo()+" 姓名："+this.getStudentName()+" 英語成績："+this.getEnglishScore()+" 數學成績："+this.getMathScore()+" 計算機成績："+this.getComputerScore()+" 總成績："+this.getTotalScore();
}

//重寫equals方法
public boolean equals(Object obj) {
if(obj == null){
return false;
}
if(!(obj instanceof Student)){
return false;
}
Student student = (Student)obj;
if(this.studentNo.equals(student.getStudentName())) { //照現實來說，比較是不是同一個學生，應該只是看他的學號是不是相同
return true;
} else {
return false;
}

}

/*以下為get和set方法，我個人認為，totalScore的set的方法沒必要要，因為它是由其它成績計算出來的
在set方法中，沒設置一次值，調用一次sum方法，即重新計算總成績
*/
public String getStudentNo() {
return studentNo;
}
public void setStudentNo(String studentNo) {
this.studentNo = studentNo;
sum();
}
public String getStudentName() {
return studentName;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
sum();
}
public double getEnglishScore() {
return englishScore;
}
public void setEnglishScore(double englishScore) {
this.englishScore = englishScore;
sum();
}
public double getComputerScore() {
return computerScore;
}
public void setComputerScore(double computerScore) {
this.computerScore = computerScore;
sum();
}
public double getMathScore() {
return mathScore;
}
public void setMathScore(double mathScore) {
this.mathScore = mathScore;
sum();
}
public double getTotalScore() {
return totalScore;
}

}

//Student子類學習委員類的實現
class StudentXW extends Student {

//重寫父類Student的testScore()方法
@Override
public double testScore() {
return sum()/3+3;
}

public StudentXW() {}

//StudentXW的構造函數
public StudentXW(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
super(studentNo,studentName,englishSocre,computerScore,mathScore);
}
}

//Student子類班長類的實現
class StudentBZ extends Student {

//重寫父類Student的testScore()方法
@Override
public double testScore() {
return sum()/3+5;
}

public StudentBZ() {}

//StudentXW的構造函數
public StudentBZ(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
super(studentNo,studentName,englishSocre,computerScore,mathScore);
}
}

//測試類
public class Test {

public static void main(String[] args) {

//生成若干個student類、StudentXW類、StudentBZ類
Student student1 = new Student("s001","張三",70.5,50,88.5);
Student student2 = new Student("s002","李四",88,65,88.5);
Student student3 = new Student("s003","王五",67,77,90);
StudentXW student4 = new StudentXW("s004","李六",99,88,99.5);
StudentBZ student5 = new StudentBZ("s005","朱漆",56,65.6,43.5);

Student[] students = {student1,student2,student3,student4,student5};

for(int i = 0 ; i<students.length; i++){
double avgScore = students[i].testScore();
System.out.println(students[i].getStudentName()+"學生的評測成績為："+ avgScore+"分");
}

}
}
運行結果為：
張三學生的評測成績為：69.66666666666667分
李四學生的評測成績為：80.5分
王五學生的評測成績為：78.0分
李六學生的評測成績為：98.5分
朱漆學生的評測成績為：60.03333333333333分

2. 給段最簡單的java代碼 讓我新手看一下

最簡單的java代碼肯定就是這個了，如下：
public class MyFirstApp
{
public static void main(String[] args)
{
System.out.print("Hello world");
}
}
「hello world」就是應該是所有學java的新手看的第一個代碼了。如果是零基礎的新手朋友們可以來我們的java實驗班試聽，有免費的試聽課程幫助學習java必備基礎知識，有助教老師為零基礎的人提供個人學習方案，學習完成後有考評團進行專業測試，幫助測評學員是否適合繼續學習java，15天內免費幫助來報名體驗實驗班的新手快速入門java，更好的學習java！

3. 求JAVA簡易計算機源代碼

試試這個
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.applet.*;
public class SZJSQ extends JApplet implements ActionListener
{
boolean i=true;
private JButton num0=new JButton("0");
private JButton num1=new JButton("1");
private JButton num2=new JButton("2");
private JButton num3=new JButton("3");
private JButton num4=new JButton("4");
private JButton num5=new JButton("5");
private JButton num6=new JButton("6");
private JButton num7=new JButton("7");
private JButton num8=new JButton("8");
private JButton num9=new JButton("9");
private JButton zuok=new JButton("(");
private JButton youk=new JButton(")");
private JButton dian=new JButton(".");
private JButton NULL=new JButton("N");
private JButton plu=new JButton("+");
private JButton min=new JButton("-");
private JButton mul=new JButton("x");
private JButton div=new JButton("/");
private JButton equ=new JButton("=");
private JButton cle=new JButton("C");//清除
private JTextField space=new JTextField(30);

public void init()
{
JPanel text=new JPanel();
text.setLayout(new FlowLayout());
text.add(space);
JPanel buttons=new JPanel();
buttons.setLayout(new GridLayout(5,4));
buttons.add(num9);
buttons.add(num8);
buttons.add(num7);
buttons.add(plu);
buttons.add(num6);
buttons.add(num5);
buttons.add(num4);
buttons.add(min);
buttons.add(num3);
buttons.add(num2);
buttons.add(num1);
buttons.add(mul);
buttons.add(num0);
buttons.add(cle);
buttons.add(equ);
buttons.add(div);
buttons.add(zuok);
buttons.add(youk);
buttons.add(dian);
buttons.add(NULL);
(num9).addActionListener(this);
(num8).addActionListener(this);
(num7).addActionListener(this);
(num6).addActionListener(this);
(num5).addActionListener(this);
(num4).addActionListener(this);
(num3).addActionListener(this);
(num2).addActionListener(this);
(num1).addActionListener(this);
(num0).addActionListener(this);
(plu).addActionListener(this);
(min).addActionListener(this);
(mul).addActionListener(this);
(div).addActionListener(this);
(equ).addActionListener(this);
(cle).addActionListener(this);
(zuok).addActionListener(this);
(youk).addActionListener(this);
(dian).addActionListener(this);
setLayout(new BorderLayout());
add("North",text);
add("South",buttons);
space.setText("0");
}

public void actionPerformed(ActionEvent e)
{

if(e.getSource()==num9)
{
if(i==true)
{
space.setText("9");
i=false;
}
else space.setText(space.getText()+'9');
}
if(e.getSource()==num8)
{
if(i==true)
{
space.setText("8");
i=false;
}
else space.setText(space.getText()+'8');
}
if(e.getSource()==num7)
{
if(i==true)
{
space.setText("7");
i=false;
}
else space.setText(space.getText()+'7');
}
if(e.getSource()==num6)
{
if(i==true)
{
space.setText("6");
i=false;
}
else space.setText(space.getText()+'6');
}
if(e.getSource()==num5)
{
if(i==true)
{
space.setText("5");
i=false;
}
else space.setText(space.getText()+'5');
}
if(e.getSource()==num4)
{
if(i==true)
{
space.setText("4");
i=false;
}
else space.setText(space.getText()+'4');
}
if(e.getSource()==num3)
{
if(i==true)
{
space.setText("3");
i=false;
}
else space.setText(space.getText()+'3');
}
if(e.getSource()==num2)
{
if(i==true)
{
space.setText("2");
i=false;
}
else space.setText(space.getText()+'2');
}
if(e.getSource()==num1)
{
if(i==true)
{
space.setText("1");
i=false;
}
else space.setText(space.getText()+'1');
}
if(e.getSource()==num0)
{
if(i==true)
{
space.setText("0");
i=false;
}
else space.setText(space.getText()+'0');
}
if(e.getSource()==zuok)
{
if(i==true)
{
space.setText("(");
i=false;
}
else space.setText(space.getText()+'(');
} if(e.getSource()==youk)
{
if(i==false)
space.setText(space.getText()+')');
}
if(e.getSource()==dian)
{
if(i==false)
space.setText(space.getText()+'.');
}
if(e.getSource()==plu)
{
space.setText(space.getText()+'+');
i=false;
}
if(e.getSource()==min)
{
space.setText(space.getText()+'-');
i=false;
}
if(e.getSource()==mul)
{
space.setText(space.getText()+'*');
i=false;
}
if(e.getSource()==div)
{
space.setText(space.getText()+'/');
i=false;
}
if(e.getSource()==equ)
{
space.setText(String.valueOf(Calculator(space.getText())));
i=true;
}
if(e.getSource()==cle)
{
space.setText("0");
i=true;
}

}

public double Calculator(String f)//科學計算
{
int i=0,j=0,k;
char c;
StringBuffer s=new StringBuffer();
s.append(f);
s.append('=');
String formula=s.toString();
char[] anArray;
anArray=new char[50];
Stack<Character> mystack=new Stack<Character>();
while(formula.charAt(i)!='=')
{
c=formula.charAt(i);
switch(c)
{
case '(': mystack.push(new Character(c));
i++;
break;
case ')':
while(mystack.peek().charValue()!='(')
{
anArray[j++]=mystack.pop().charValue();
}
mystack.pop();
i++;
break;
case '+':
case '-':
while(!mystack.empty()&&mystack.peek().charValue()!='(')
{
anArray[j++]=mystack.pop().charValue();

}
mystack.push(new Character(c));
i++;
break;
case '*':
case '/':
while(!mystack.empty()&&(mystack.peek().charValue()=='*'||mystack.peek().charValue()=='/'))
{
anArray[j++]=mystack.pop().charValue();
}
mystack.push(new Character(c));
i++;
break;
case' ': i++;
break;
default: while((c>='0'&&c<='9')||c=='.')
{
anArray[j++]=c;
i++;
c=formula.charAt(i);
}
anArray[j++]='#';
break;
}
}
while(!(mystack.empty()))
anArray[j++]=mystack.pop().charValue();

i=0;
int count;
double a,b,d;
Stack<Double> mystack1 =new Stack<Double>();
while(i<j)
{
c=anArray[i];
switch(c)
{
case '+':
a=mystack1.pop().doubleValue();
b=mystack1.pop().doubleValue();
d=b+a;
mystack1.push(new Double(d));
i++;
break;
case '-':
a=mystack1.pop().doubleValue();
b=mystack1.pop().doubleValue();
d=b-a;
mystack1.push(new Double(d));
i++;
break;
case '*':
a=mystack1.pop().doubleValue();
b=mystack1.pop().doubleValue();
d=b*a;
mystack1.push(new Double(d));
i++;
break;
case '/':
a=mystack1.pop().doubleValue();
b=mystack1.pop().doubleValue();
if(a!=0)
{
d=b/a;
mystack1.push(new Double(d));
i++;
}
else
{
System.out.println("Error!");
}
break;
default:
d=0;count=0;
while((c>='0'&&c<='9'))
{
d=10*d+c-'0';
i++;
c=anArray[i];
}
if(c=='.')
{
i++;
c=anArray[i];
while((c>='0'&&c<='9'))
{
count++;
d=d+(c-'0')/Math.pow(10,count);
i++;
c=anArray[i];
}
}
if(c=='#')
mystack1.push(new Double(d));
i++;
break;
}
}
return(mystack1.peek().doubleValue());
}
}

4. 一段最簡單的java代碼程序有哪些

public class HelloWorld{

public static void main(String[] args){

System.out.println("hello world!");

}

}

5. 用Java編寫簡易記事本源代碼

importjava.awt.BorderLayout;importjava.awt.Container;importjava.awt.Font;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;importjava.awt.event.InputEvent;importjava.awt.event.KeyAdapter;importjava.awt.event.KeyEvent;importjava.awt.event.MouseAdapter;importjava.awt.event.MouseEvent;importjava.awt.event.WindowAdapter;importjava.awt.event.WindowEvent;importjava.io.BufferedReader;importjava.io.BufferedWriter;importjava.io.File;importjava.io.FileReader;importjava.io.FileWriter;importjava.io.IOException;importjavax.swing.BorderFactory;importjavax.swing.JFileChooser;importjavax.swing.JFrame;importjavax.swing.JLabel;importjavax.swing.JMenu;importjavax.swing.JMenuBar;importjavax.swing.JMenuItem;importjavax.swing.JOptionPane;importjavax.swing.JPopupMenu;importjavax.swing.JScrollPane;importjavax.swing.JTextArea;importjavax.swing.KeyStroke;importjavax.swing.ScrollPaneConstants;importjavax.swing.SwingConstants;{privateJMenuItemmenuOpen;privateJMenuItemmenuSave;privateJMenuItemmenuSaveAs;privateJMenuItemmenuClose;privateJMenueditMenu;privateJMenuItemmenuCut;privateJMenuItemmenuCopy;privateJMenuItemmenuPaste;privateJMenuItemmenuAbout;privateJTextAreatextArea;privateJLabelstateBar;;privateJPopupMenupopUpMenu;publicJNotePadUI(){super("新建文本文件");setUpUIComponent();setUpEventListener();setVisible(true);}privatevoidsetUpUIComponent(){setSize(640,480);//菜單欄JMenuBarmenuBar=newJMenuBar();//設置「文件」菜單JMenufileMenu=newJMenu("文件");menuOpen=newJMenuItem("打開");//快捷鍵設置menuOpen.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,InputEvent.CTRL_MASK));menuSave=newJMenuItem("保存");menuSave.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,InputEvent.CTRL_MASK));menuSaveAs=newJMenuItem("另存為");menuClose=newJMenuItem("關閉");menuClose.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q,InputEvent.CTRL_MASK));fileMenu.add(menuOpen);fileMenu.addSeparator();//分隔線fileMenu.add(menuSave);fileMenu.add(menuSaveAs);fileMenu.addSeparator();//分隔線fileMenu.add(menuClose);//設置「編輯」菜單JMenueditMenu=newJMenu("編輯");menuCut=newJMenuItem("剪切");menuCut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,InputEvent.CTRL_MASK));menuCopy=newJMenuItem("復制");menuCopy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,InputEvent.CTRL_MASK));menuPaste=newJMenuItem("粘貼");menuPaste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V,InputEvent.CTRL_MASK));editMenu.add(menuCut);editMenu.add(menuCopy);editMenu.add(menuPaste);//設置「關於」菜單JMenuaboutMenu=newJMenu("關於");menuAbout=newJMenuItem("關於JNotePad");aboutMenu.add(menuAbout);menuBar.add(fileMenu);menuBar.add(editMenu);menuBar.add(aboutMenu);setJMenuBar(menuBar);//文字編輯區域textArea=newJTextArea();textArea.setFont(newFont("宋體",Font.PLAIN,16));textArea.setLineWrap(true);JScrollPanepanel=newJScrollPane(textArea,ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);ContainercontentPane=getContentPane();contentPane.add(panel,BorderLayout.CENTER);//狀態欄stateBar=newJLabel("未修改");stateBar.setHorizontalAlignment(SwingConstants.LEFT);stateBar.setBorder(BorderFactory.createEtchedBorder());contentPane.add(stateBar,BorderLayout.SOUTH);popUpMenu=editMenu.getPopupMenu();fileChooser=newJFileChooser();}privatevoidsetUpEventListener(){//按下窗口關閉鈕事件處理addWindowListener(newWindowAdapter(){publicvoidwindowClosing(WindowEvente){closeFile();}});//菜單-打開menuOpen.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){openFile();}});//菜單-保存menuSave.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){saveFile();}});//菜單-另存為menuSaveAs.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){saveFileAs();}});//菜單-關閉文件menuClose.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){closeFile();}});//菜單-剪切menuCut.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){cut();}});//菜單-復制menuCopy.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){();}});//菜單-粘貼menuPaste.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){paste();}});//菜單-關於menuAbout.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){//顯示對話框JOptionPane.showOptionDialog(null,"程序名稱:\nJNotePad\n"+"程序設計:\n\n"+"簡介:\n一個簡單的文字編輯器\n"+"可作為驗收Java的實現對象\n"+"歡迎網友下載研究交流\n\n"+"/","關於JNotePad",JOptionPane.DEFAULT_OPTION,JOptionPane.INFORMATION_MESSAGE,null,null,null);}});//編輯區鍵盤事件textArea.addKeyListener(newKeyAdapter(){publicvoidkeyTyped(KeyEvente){processTextArea();}});//編輯區滑鼠事件textArea.addMouseListener(newMouseAdapter(){publicvoidmouseReleased(MouseEvente){if(e.getButton()==MouseEvent.BUTTON3)popUpMenu.show(editMenu,e.getX(),e.getY());}publicvoidmouseClicked(MouseEvente){if(e.getButton()==MouseEvent.BUTTON1)popUpMenu.setVisible(false);}});}privatevoidopenFile(){if(isCurrentFileSaved()){//文件是否為保存狀態open();//打開}else{//顯示對話框intoption=JOptionPane.showConfirmDialog(null,"文件已修改，是否保存？","保存文件？",JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null);switch(option){//確認文件保存caseJOptionPane.YES_OPTION:saveFile();//保存文件break;//放棄文件保存caseJOptionPane.NO_OPTION:open();break;}}}(){if(stateBar.getText().equals("未修改")){returnfalse;}else{returntrue;}}privatevoidopen(){//fileChooser是JFileChooser的實例//顯示文件選取的對話框intoption=fileChooser.showDialog(null,null);//使用者按下確認鍵if(option==JFileChooser.APPROVE_OPTION){try{//開啟選取的文件BufferedReaderbuf=newBufferedReader(newFileReader(fileChooser.getSelectedFile()));//設定文件標題setTitle(fileChooser.getSelectedFile().toString());//清除前一次文件textArea.setText("");//設定狀態欄stateBar.setText("未修改");//取得系統相依的換行字元StringlineSeparator=System.getProperty("line.separator");//讀取文件並附加至文字編輯區Stringtext;while((text=buf.readLine())!=null){textArea.append(text);textArea.append(lineSeparator);}buf.close();}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"開啟文件失敗",JOptionPane.ERROR_MESSAGE);}}}privatevoidsaveFile(){//從標題欄取得文件名稱Filefile=newFile(getTitle());//若指定的文件不存在if(!file.exists()){//執行另存為saveFileAs();}else{try{//開啟指定的文件BufferedWriterbuf=newBufferedWriter(newFileWriter(file));//將文字編輯區的文字寫入文件buf.write(textArea.getText());buf.close();//設定狀態欄為未修改stateBar.setText("未修改");}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"寫入文件失敗",JOptionPane.ERROR_MESSAGE);}}}privatevoidsaveFileAs(){//顯示文件對話框intoption=fileChooser.showSaveDialog(null);//如果確認選取文件if(option==JFileChooser.APPROVE_OPTION){//取得選擇的文件Filefile=fileChooser.getSelectedFile();//在標題欄上設定文件名稱setTitle(file.toString());try{//建立文件file.createNewFile();//進行文件保存saveFile();}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"無法建立新文件",JOptionPane.ERROR_MESSAGE);}}}privatevoidcloseFile(){//是否已保存文件if(isCurrentFileSaved()){//釋放窗口資源，而後關閉程序dispose();}else{intoption=JOptionPane.showConfirmDialog(null,"文件已修改，是否保存？","保存文件？",JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null);switch(option){caseJOptionPane.YES_OPTION:saveFile();break;caseJOptionPane.NO_OPTION:dispose();}}}privatevoidcut(){textArea.cut();stateBar.setText("已修改");popUpMenu.setVisible(false);}privatevoid(){textArea.();popUpMenu.setVisible(false);}privatevoidpaste(){textArea.paste();stateBar.setText("已修改");popUpMenu.setVisible(false);}privatevoidprocessTextArea(){stateBar.setText("已修改");}publicstaticvoidmain(String[]args){newJNotePadUI();}}

6. 求一個簡單又有趣的JAVA小游戲代碼

具體如下：

連連看的小源碼

package Lianliankan;

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class lianliankan implements ActionListener

{

JFrame mainFrame; //主面板

Container thisContainer;

JPanel centerPanel,southPanel,northPanel; //子面板

JButton diamondsButton[][] = new JButton[6][5];//游戲按鈕數組

JButton exitButton,resetButton,newlyButton; //退出，重列，重新開始按鈕

JLabel fractionLable=new JLabel("0"); //分數標簽

JButton firstButton,secondButton; //

分別記錄兩次被選中的按鈕

int grid[][] = new int[8][7];//儲存游戲按鈕位置

static boolean pressInformation=false; //判斷是否有按鈕被選中

int x0=0,y0=0,x=0,y=0,fristMsg=0,secondMsg=0,validateLV; //游戲按鈕的位置坐標

int i,j,k,n;//消除方法控制

代碼（code）是程序員用開發工具所支持的語言寫出來的源文件，是一組由字元、符號或信號碼元以離散形式表示信息的明確的規則體系。

對於字元和Unicode數據的位模式的定義，此模式代表特定字母、數字或符號（例如 0x20 代表一個空格，而 0x74 代表字元「t」）。一些數據類型每個字元使用一個位元組；每個位元組可以具有 256 個不同的位模式中的一個模式。

在計算機中，字元由不同的位模式（ON 或 OFF）表示。每個位元組有 8 位，這 8 位可以有 256 種不同的 ON 和 OFF 組合模式。對於使用 1 個位元組存儲每個字元的程序，通過給每個位模式指派字元可表示最多 256 個不同的字元。2 個位元組有 16 位，這 16 位可以有 65,536 種唯一的 ON 和 OFF 組合模式。使用 2 個位元組表示每個字元的程序可表示最多 65,536 個字元。

單位元組代碼頁是字元定義，這些字元映射到每個位元組可能有的 256 種位模式中的每一種。代碼頁定義大小寫字元、數字、符號以及 !、@、#、% 等特殊字元的位模式。每種歐洲語言（如德語和西班牙語）都有各自的單位元組代碼頁。

雖然用於表示 A 到 Z 拉丁字母表字元的位模式在所有的代碼頁中都相同，但用於表示重音字元（如"é"和"á"）的位模式在不同的代碼頁中卻不同。如果在運行不同代碼頁的計算機間交換數據，必須將所有字元數據由發送計算機的代碼頁轉換為接收計算機的代碼頁。如果源數據中的擴展字元在接收計算機的代碼頁中未定義，那麼數據將丟失。

如果某個資料庫為來自許多不同國家的客戶端提供服務，則很難為該資料庫選擇這樣一種代碼頁，使其包括所有客戶端計算機所需的全部擴展字元。而且，在代碼頁間不停地轉換需要花費大量的處理時間。

7. 求編寫一個超級簡單的Java的程序源代碼

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

class ConstructFrame extends JFrame
{

private static final long serialVersionUID = 1L;
String value1="",result,value2="";
int flag=0,fix=0,sum=1;
Boolean happy;
JTextField text=new JTextField(30);
int flagsum=0;
Container c=getContentPane();
JButton buttonx;
ConstructFrame()
{ super("計算器");
c.setLayout(null);
c.setBackground(Color.blue);
this.setSize(400, 400);
c.add(text);
text.setHorizontalAlignment(JTextField.RIGHT);
final JButton buttonx=new JButton("BackSpace");
c.add(buttonx);
buttonx.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
int count=0;
String temp;
if(flag==0)
{
count=value1.length();
if(count!=1)
temp=value1.substring(0, count-1);
else
temp="0";
value1=temp;

}
else
{
count=value2.length();
if(count!=1)
temp=value2.substring(0, count-1);
else
temp="0";
value2=temp;
}
text.setText(temp);
}
});
final JButton buttony=new JButton("CE");
c.add(buttony);
buttony.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
value1="";
value2="";
flag=0;
text.setText("0");
}
});

final JButton button1=new JButton("1");
c.add(button1);
button1.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+1;
temp=value1;
}
else
{
value2=value2+1;
temp=value2;
}
text.setText(temp);
}
});

final JButton button2=new JButton(" 2 ");
c.add(button2);
button2.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+2;
temp=value1;
}
else
{
value2=value2+2;
temp=value2;
}
text.setText(temp);
}
});

final JButton button3=new JButton("3");
c.add(button3);
button3.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+3;
temp=value1;
}
else
{
value2=value2+3;
temp=value2;
}
text.setText(temp);
}
});
final JButton button4=new JButton("4");
c.add(button4);
button4.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+4;
temp=value1;
}
else
{
value2=value2+4;
temp=value2;
}
text.setText(temp);
}
});
final JButton button5=new JButton("5");
c.add(button5);
button5.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+5;
temp=value1;
}
else
{
value2=value2+5;
temp=value2;
}
text.setText(temp);
}
});
final JButton button6=new JButton("6");
c.add(button6);
button6.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+6;
temp=value1;
}
else
{
value2=value2+6;
temp=value2;
}
text.setText(temp);
}
});
final JButton button7=new JButton("7");
c.add(button7);
button7.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+7;
temp=value1;
}
else
{
value2=value2+7;
temp=value2;
}
text.setText(temp);
}
});
final JButton button8=new JButton("8");
c.add(button8);
button8.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+8;
temp=value1;
}
else
{
value2=value2+8;
temp=value2;
}
text.setText(temp);
}
});
final JButton button9=new JButton("9");
c.add(button9);
button9.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+9;
temp=value1;
}
else
{
value2=value2+9;
temp=value2;
}
text.setText(temp);
}
});
final JButton button0=new JButton("0");
c.add(button0);
button0.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
String temp;
if(flag==0)
{
value1=value1+0;
temp=value1;
}
else
{
value2=value2+0;
temp=value2;
}
text.setText(temp);
}
});

final JButton buttonadd=new JButton(" + ");
c.add(buttonadd);
buttonadd.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
flag=1;
fix=1;
flagsum=0;
}
});

final JButton buttonsubtract=new JButton(" - ");
c.add(buttonsubtract);
buttonsubtract.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
flag=1;
fix=2;
flagsum=0;
}
});
final JButton buttoncheng=new JButton(" * ");
c.add(buttoncheng);
buttoncheng.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
flag=1;
fix=3;
flagsum=0;
}
});

final JButton buttonchu=new JButton(" / ");
c.add(buttonchu);
buttonchu.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
flag=1;
flagsum=0;
fix=4;
}
});
final JButton buttonequal=new JButton(" = ");
c.add(buttonequal);
buttonequal.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
double temp1,temp2;
double temp=0;
flagsum=0;
temp1=Double.parseDouble(value1);
temp2=Double.parseDouble(value2);
flag=0;
switch(fix)
{
case 1: temp=temp1+temp2;break;
case 2: temp=temp1-temp2;break;
case 3: temp=temp1*temp2;break;
case 4: temp=temp1/temp2;break;
}
result=Double.valueOf(temp).toString();
value1=result;
value2="";
flag=1;
text.setText(result);
}
});
final JButton buttonpoint=new JButton(".");
c.add(buttonpoint);
buttonpoint.addMouseListener(new MouseAdapter()
{

public void mousePressed(MouseEvent e)
{ if(flagsum==0)
{
String temp;

if(flag==0 )
{
value1=value1+".";
temp=value1;
}
else
{
value2=value2+".";
temp=value2;
}

flagsum=1;
text.setText(temp);
}
}

});
JButton buttonz=new JButton("Start");
c.add(buttonz);
buttonz.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{ if(sum%2==1)
{
happy=true;
text.setText("0.");
flag=0;

}
else
{
happy=false;
value1="";
value2="";
text.setText("");
}
text.setEnabled(happy);
button1.setEnabled(happy);
button2.setEnabled(happy);
button3.setEnabled(happy);
button4.setEnabled(happy);
button5.setEnabled(happy);
button6.setEnabled(happy);
button7.setEnabled(happy);
button8.setEnabled(happy);
button9.setEnabled(happy);
button0.setEnabled(happy);
buttonx.setEnabled(happy);
buttony.setEnabled(happy);
buttonadd.setEnabled(happy);
buttonsubtract.setEnabled(happy);
buttonpoint.setEnabled(happy);
buttonequal.setEnabled(happy);
buttoncheng.setEnabled(happy);
buttonchu.setEnabled(happy);
sum++;
}
});
button1.setEnabled(false);
button2.setEnabled(false);
button3.setEnabled(false);
button4.setEnabled(false);
button5.setEnabled(false);
button6.setEnabled(false);
button7.setEnabled(false);
button8.setEnabled(false);
button9.setEnabled(false);
button0.setEnabled(false);
buttonx.setEnabled(false);
buttony.setEnabled(false);
buttonadd.setEnabled(false);
buttonsubtract.setEnabled(false);
buttonpoint.setEnabled(false);
buttonequal.setEnabled(false);
buttoncheng.setEnabled(false);
buttonchu.setEnabled(false);
text.setEnabled(false);
text.setBounds(20, 20, 200, 40);
buttonx.setBounds(20, 60,100, 40);
buttony.setBounds(140, 60,100, 40);
buttonz.setBounds(260, 60,80, 40);
button1.setBounds(20, 120,60, 40);
button2.setBounds(100, 120,60, 40);
button3.setBounds(180, 120,60, 40);
buttonadd.setBounds(260, 120,60, 40);
button4.setBounds(20, 180,60, 40);
button5.setBounds(100, 180,60, 40);
button6.setBounds(180, 180,60, 40);
buttonsubtract.setBounds(260, 180,60, 40);
button7.setBounds(20, 240,60, 40);
button8.setBounds(100, 240,60, 40);
button9.setBounds(180, 240,60, 40);
buttoncheng.setBounds(260,240,60,40);
button0.setBounds(20, 300,60, 40);
buttonpoint.setBounds(100, 300, 60, 40);
buttonequal.setBounds(180,300,60, 40);
buttonchu.setBounds(260, 300,60, 40);
setVisible(true);

}
class MYMouseEvent extends MouseAdapter
{
public void mousePressed(MouseEvent e)
{
value1=e.toString();
text.setText(value1);
}
}
}
class Calutator
{
public static void main(String[] args)
{
new ConstructFrame();
}
}
你自己慢慢的看吧！