java语言程序设计(第三版)书本代码

JButton button9=new JButton("9");
JButton button_dian=new JButton(".");
JButton button_jia=new JButton("+");
JButton button_jian=new JButton("-");
JButton button_cheng=new JButton("*");
double d1=23.4;
double d2=35.1;
if(d2>=d1)
{ System.out.println(d1);
System.out.println(d2);
}
else
{System.out.println(d2);
System.out.println(d1);}
}
}
4、计算器
import java.awt.*;
JButton button_chu=new JButton("/");
JButton button_de=new JButton("=");
////////////////////////////////////////////////////////////////////////
public static void main(String[] args)
button.addActionListener(this);
field=new JTextField(23);
add(field); add(button);
}
public void actionPerformed(ActionEvent e) {field.setText("Applet与Application的合并运行");}
}
}
//----------------------------
if (key_n2==2)
{
if(s_n != ".")
{
str2=str2+s_n;
jg_TextField.setText(str2);
}
if(s_n == "." && key_dian==0 )
{
str2=str2+s_n;
jg_TextField.setText(str1);
button6.addActionListener(a1);
button5.addActionListener(a1);
button4.addActionListener(a1);
button3.addActionListener(a1);
button2.addActionListener(a1);
window.add("Center", app);
app.init();
window.setVisible(true);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void init() {
button=new JButton("显示");
3、温度
一
class W1
{
public static void main(String args[])
{
int c=28;
switch(c<10?1:c<25?2:c<35?3:4)
{
case 1:
System.out.println(" "+c+"摄氏度有点冷");
break;
case 2:
System.out.println(" "+c+"摄氏度正合适");
{
Caljs=newCal();
}
/////////////////////////////////////////////////////////////////////////
//---------------------构造函数--------------------------
publicCal()
FuHao a3=new FuHao();
button_jia.addActionListener(a3);
button_jian.addActionListener(a3);
button_cheng.addActionListener(a3);
button_chu.addActionListener(a3);
break;
case 3:
System.out.println(" "+c+"摄氏度有点热");
break;
default:
System.out.println(" "+c+"摄氏度太热了");
break;
}
}
}
二
温度（无退出）
class C1 {
public static void main(String args[]) {
key_dian=1;
}
}
}
}
class QingChu implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jg_TextField.setText("");
JButton button;
JTextField field;
public static void main(String[] args) {
JFrame window=new JFrame("AppDemo");
window.setBounds(200,200,500,400);
AppDemo app=new AppDemo();
book1.setname("C语言教程");
System.out.println(book1.getname());
}
}
class SetBook
{
private String name="java语言教程";
private String author;
public void setname(String inName)
class ShuZi implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String s_n= ( (JButton)e.getSource()).getText();
//-----------------------------------
if (key_n2==1)
{
if(s_n != ".")
{
str1=str1+s_n;
jg_TextField.setText(str1);
}
if(s_n == "." && key_dian==0 )
{
str1=str1+s_n;
jg_TextField.setText(str1);
key_dian=1;
import java.awt.event.*;
import javax.swing.*;
public class Cal
{
String str1=""; //运算数1
String str2=""; //运算数2
String fh=""; //运算符
String jg=""; //结果
double djg=0;
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ShuZi a1=new ShuZi();
button9.addActionListener(a1); //注册监听器
button8.addActionListener(a1);
button7.addActionListener(a1);
DengYu a4=new DengYu();
button_de.addActionListener(a4);
}
//----------------------------------构造函数结束-----------------------------------
//监听器类-----内部类-------
JButton button4=new JButton("4");
JButton button5=new JButton("5");
JButton button6=new JButton("6");
JButton button7=new JButton("7");
JButton button8=new JButton("8");
button1.addActionListener(a1);
button0.addActionListener(a1);
button_dian.addActionListener(a1);
QingChu a2=new QingChu();
button_clear.addActionListener(a2);
pan2.add(button7);
pan2.add(button8);
pan2.add(button9);
pan2.add(button_chu);
pan2.add(button4);
pan2.add(button5);
pan2.add(button6);
pan2.add(button_cheng);
int key_dian=0; //输入小数点后为"1"，没输入为零，避免重复输入小数点。
int key_n2=1; //是"1"给str1赋值。。是"2"给str2赋值
JFrame frame=new JFrame("作业---计算器");
JTextField jg_TextField=new JTextField(20);
{
//创建第一个面板，将文本框放入面板1
JPanel pan1=new JPanel();
pan1.add(jg_TextField);
//创建第二个面板，采用grid布局，将组件放入面板
JPanel pan2=ntLayout(new GridLayout(4,4,5,5));
JButton button_clear=new JButton("清除");
JButton button0=new JButton("0");
JButton button1=new JButton("1");
JButton button2=new JButton("2");
JButton button3=new JButton("3");
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(pan1,BorderLayout.NORTH);
frame.getContentPane().add(pan2,BorderLayout.CENTER);
pan2.add(button1);
pan2.add(button2);
pan2.add(button3);
pan2.add(button_jian);
pan2.add(button0);
pan2.add(button_dian);
pan2.add(button_de);
pan2.add(button_jia);
publicstaticvoidmainstringlargsjfofnewjf0创建一个主窗口对象f是实例化jf0类创建的jddnewjdf这是一个对话框窗口12
书本代码：
输出C语言教程。
class a
{
public static void main(String[] args)
{
SetBook book1=new SetBook();
pan2.setBorder(BorderFactory.createEmptyBorder(20,5,20,5));
//创建面板三，放入清零按钮
JPanel pan3=new JPanel();
pan3.add(button_clear);
//-------------------------------------------------------------
{
name=inName;
}
public String getname()
{
return name;
}
}
2、显示
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.applet.*;
public class AppDemo extends Applet implements ActionListener {
frame.getContentPane().add(pan3,BorderLayout.SOUTH);
frame.setLocation(300, 200); //主窗口位置
frame.setResizable(false); //窗口不能调节大小
frame.pack();
frame.setVisible(true);