Java几何计算器案例代码

博主：君若
发布时间：2019 年 06 月 07 日
1212 次浏览
2 条评论
16050字数
分类： Java

成果截图

![](https://jrboy.oss-cn-chengdu.aliyuncs.com/wp-content/uploads/2019/06/2019060715114862-300x200.png)![](https://jrboy.oss-cn-chengdu.aliyuncs.com/wp-content/uploads/2019/06/2019060715120368-300x200.png)

代码展示

###### 1，程序主窗体代码（CalculatorWindow.java）

```
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;

public class CalculatorWindow extends JFrame implements ActionListener,ItemListener {

CardLayout mycard;
JPanel controPanel,pCenter;
JComboBox chooseList;
JMenuBar menuBar;
JMenu menu;
JMenuItem mainWindow,exit;

public CalculatorWindow(){
setTitle("常见几何图形计算器");

menuBar = new JMenuBar();
menu = new JMenu("操作");
mainWindow = new JMenuItem("主界面");
mainWindow.addActionListener(this);
exit = new JMenuItem("退出");
exit.addActionListener(this);
menu.add(mainWindow);
menu.add(exit);
menuBar.add(menu);
setJMenuBar(menuBar);

mycard = new CardLayout();
pCenter = new JPanel();
pCenter.setLayout(mycard);
add(pCenter,"Center");

controPanel = new JPanel();
controPanel.setLayout(new BorderLayout());

chooseList = new JComboBox();
chooseList.addItem("请点击下拉列表选择");
chooseList.addItem("矩形的基本计算");
chooseList.addItem("圆的基本计算");
chooseList.addItem("三角形的基本计算");
chooseList.addItem("圆柱的基本计算");
chooseList.addItemListener(this);

ImageIcon icon = new ImageIcon(图片地址);
JButton imageButton = new JButton(icon);

controPanel.add(imageButton,"Center");
controPanel.add(chooseList,"North");

pCenter.add("0",controPanel);
pCenter.add("1",new RectanglePanel());
pCenter.add("2",new CirclePanel());
pCenter.add("3",new TrianglePanel());
pCenter.add("4",new CylinderPanel());

setBounds(100, 100, 700, 300);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);

}

public void itemStateChanged(ItemEvent e) {
int index = chooseList.getSelectedIndex();
String choice = String.valueOf(index);
mycard.show(pCenter, choice);

}

public void actionPerformed(ActionEvent e) {
if (e.getSource() == mainWindow) {
mycard.first(pCenter);
chooseList.setSelectedIndex(0);
}
else if (e.getSource() == exit) {
System.exit(0);
}
}

public static void main(String[] args) {
new CalculatorWindow();
}

}
```

###### 2，BoxPanel.java和AbstractPanel.java的实现

```
//代码（BoxPanel.java）

import java.awt.Font;

import javax.swing.Box;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class BoxPanel extends JPanel{
JTextField text;

public BoxPanel(String s,int n) {

Box box = Box.createHorizontalBox();
box.add(new JLabel(s));
text = new JTextField(" ",n);

text.setHorizontalAlignment(JTextField.RIGHT);

text.setFont(new Font("Arial",Font.BOLD,15));
box.add(text);
add(box);

}
public JTextField getJTextField() {
return text;
}
}

//代码（AbstractPanel.java）

import javax.swing.JPanel;
import javax.swing.JTextField;

public abstract class AbstractPanel extends JPanel {
public abstract JTextField getInputTextField();
}
```

###### 3，矩形计算器的实现（RectanglePanel.java）

```
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class RectanglePanel extends AbstractPanel implements ActionListener,FocusListener{

JButton resultButton,clearButton;
JPanel leftPanel,rightPanel,buttonPanel;
JTextField widthTextField,heightTextField;
JTextField lengthTextField,areaTextField,inputTextField;
BoxPanel bpWidth,bpHeight,bpLength,bpArea;

public RectanglePanel() {
setLayout(new GridLayout(1,2));
rightPanel = new KeyJPanel(this);
leftPanel = new JPanel();

Box box = Box.createVerticalBox();
bpWidth = new BoxPanel("请输入矩形的宽", 10);
widthTextField = bpWidth.getJTextField();

widthTextField.addFocusListener(this);
bpHeight = new BoxPanel("请输入矩形的高",10);
heightTextField = bpHeight.getJTextField();
heightTextField.addFocusListener(this);
buttonPanel = new JPanel();
resultButton = new JButton("计算结果");

resultButton.addActionListener(this);
clearButton = new JButton("清空");
clearButton.addActionListener(this);
buttonPanel.add(resultButton);
buttonPanel.add(clearButton);
bpLength = new BoxPanel("矩形的周长：", 20);
lengthTextField = bpLength.getJTextField();
bpArea = new BoxPanel("矩形的面积：",20);
this.areaTextField = this.bpArea.getJTextField();

box.add(bpWidth);
box.add(bpHeight);
box.add(buttonPanel);
box.add(bpLength);
box.add(bpArea);
leftPanel.add(box);

add(leftPanel);
add(rightPanel);
}

public void actionPerformed(ActionEvent e) {

if (e.getSource() == resultButton) {
try {
double width = Double.parseDouble(widthTextField.getText());
double height = Double.parseDouble(heightTextField.getText());
lengthTextField.setText(""+2*(width + height));
areaTextField.setText(""+width*height);
} catch (NumberFormatException e1) {

JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE);
}
}

else if (e.getSource() == clearButton) {
widthTextField.setText(" ");
heightTextField.setText(" ");
}
}

public void focusGained(FocusEvent e) {
inputTextField = (JTextField)e.getSource();
}

public void focusLost(FocusEvent e) {}

public JTextField getInputTextField() {
return inputTextField;
}

}
```

###### 4，圆计算器的实现（CirclePanel.java）

```
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class CirclePanel extends AbstractPanel implements ActionListener,FocusListener{

JButton resultButton,clearButton;
JPanel leftPanel,rightPanel,buttonPanel;
JTextField radiusTextField;
JTextField lengthTextField,areaTextField,inputTextField;
BoxPanel bpRadius,bpLength,bpArea;

public CirclePanel() {
setLayout(new GridLayout(1,2));
rightPanel = new KeyJPanel(this);
leftPanel =new JPanel();

Box box = Box.createVerticalBox();
bpRadius = new BoxPanel("请输入圆的半径：", 10);
radiusTextField = bpRadius.getJTextField();

radiusTextField.addFocusListener(this);
buttonPanel = new JPanel();
resultButton = new JButton("计算结果：");

resultButton.addActionListener(this);
clearButton = new JButton("清空");
clearButton.addActionListener(this);
buttonPanel.add(resultButton);
buttonPanel.add(clearButton);
bpLength = new BoxPanel("圆的周长：", 20);
lengthTextField = bpLength.getJTextField();
bpArea = new BoxpPanel("圆的面积：", 20);
areaTextField = bpArea.getJTextField();

box.add(bpRadius);
box.add(buttonPanel);
box.add(bpLength);
box.add(bpArea);
leftPanel.add(box);

add(leftPanel);
add(rightPanel);
}

public void actionPerformed(ActionEvent e) {

if (e.getSource() == resultButton) {
try {
double radius = Double.parseDouble(radiusTextField.getText());
lengthTextField.setText(""+2*Math.PI*radius);
areaTextField.setText(""+Math.PI*radius*radius);
} catch (NumberFormatException e1) {
JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE);
}
}
else if (e.getSource() == clearButton) {
radiusTextField.setText(" ");
}
}

public void focusGained(FocusEvent e) {
inputTextField = (JTextField)e.getSource();
}

public void focusLost(FocusEvent e) {}

public JTextField getInputTextField() {
return inputTextField;
}

}
```

###### 5，三角形计算器的实现（TrianglePanel.java）

```
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class TrianglePanel extends AbstractPanel implements ActionListener,FocusListener{

JButton resultButton,clearButton;
JPanel leftPanel,rightPanel,buttonPanel;
JTextField sideATextField,sideBTextField,sideCTextField;
JTextField lengthTextField,areaTextField,inputTextField;
BoxPanel bpSideA,bpSideB,bpSideC,bpLength,bpArea;

public TrianglePanel() {
setLayout(new GridLayout(1,2));
rightPanel = new KeyJPanel(this);
leftPanel =new JPanel();

Box box = Box.createVerticalBox();
bpSideA = new BoxPanel("请输入三角形的边A：",10);
sideATextField = bpSideA.getJTextField();

sideATextField.addFocusListener(this);
bpSideB = new BoxPanel("请输入三角形的边B：",10);
sideBTextField = bpSideB.getJTextField();
sideBTextField.addFocusListener(this);
bpSideC = new BoxPanel("请输入三角形的边C：",10);
sideCTextField = bpSideC.getJTextField();
sideCTextField.addFocusListener(this);
buttonPanel = new JPanel();
resultButton = new JButton("计算结果：");

resultButton.addActionListener(this);
clearButton = new JButton("清空");
clearButton.addActionListener(this);
buttonPanel.add(resultButton);
buttonPanel.add(clearButton);

bpLength = new BoxPanel("三角形的周长：", 20);
lengthTextField = bpLength.getJTextField();
bpArea = new BoxPanel("三角形的面积：", 20);
areaTextField = bpArea.getJTextField();

box.add(bpSideA);
box.add(bpSideB);
box.add(bpSideC);
box.add(buttonPanel);
box.add(bpLength);
box.add(bpArea);
leftPanel.add(box);

add(leftPanel);
add(rightPanel);
}

public void actionPerformed(ActionEvent e) {

if (e.getSource() == resultButton) {
try {
double sideA = Double.parseDouble(sideATextField.getText());
double sideB = Double.parseDouble(sideBTextField.getText());
double sideC = Double.parseDouble(sideCTextField.getText());

if ((sideA + sideB>sideC)&&(sideA + sideC>sideB)&&(sideB + sideC>sideA)) {
double p = (sideA + sideB +sideC)/2.0;
lengthTextField.setText("" + 2 * p);
double area = Math.sqrt(p * (p - sideA) * (p - sideB) *(p - sideC));
areaTextField.setText("" + area);
}
else {
JOptionPane.showMessageDialog(this, "这不构成一个三角形，请重新输入三边","警告对话框",JOptionPane.WARNING_MESSAGE);
}
} catch (NumberFormatException e1) {
JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE);
}
}
else if (e.getSource() == clearButton) {
sideATextField.setText(" ");
sideBTextField.setText(" ");
sideCTextField.setText(" ");
}
}

public void focusGained(FocusEvent e) {
inputTextField = (JTextField)e.getSource();
}

public void focusLost(FocusEvent e) {}

public JTextField getInputTextField() {
return inputTextField;
}

}
```

###### 6，圆柱计算器的实现（CylinderPanel.java）

```
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class CylinderPanel extends AbstractPanel implements ActionListener,FocusListener{

JButton resultButton,clearButton;
JPanel leftPanel,rightPanel,buttonPanel;
JTextField radiusTextField,highTextField;
JTextField surfaceAreaTextField,volumeTextField,inputTextField;
BoxPanel bpRadius,bpHeight,bpSurfaceArea,bpVolume;

public CylinderPanel() {
setLayout(new GridLayout(1,2));
rightPanel = new KeyJPanel(this);
leftPanel =new JPanel();

Box box = Box.createVerticalBox();
bpRadius = new BoxPanel("请输入圆柱的底面半径：", 10);
radiusTextField = bpRadius.getJTextField();
radiusTextField.addFocusListener(this);
bpHeight = new BoxPanel("请输入圆柱的高：", 10);
highTextField = bpHeight.getJTextField();
highTextField.addFocusListener(this);
buttonPanel = new JPanel();
resultButton = new JButton("计算结果：");
resultButton.addActionListener(this);
clearButton = new JButton("清空");
clearButton.addActionListener(this);
buttonPanel.add(resultButton);
buttonPanel.add(clearButton);
bpSurfaceArea = new BoxPanel("圆柱的表面积：", 20);
this.surfaceAreaTextField = this.bpSurfaceArea.getJTextField();
bpVolume = new BoxPanel("圆柱的体积：", 20);
this.volumeTextField = this.bpVolume.getJTextField();
box.add(bpRadius);
box.add(bpHeight);
box.add(buttonPanel);
box.add(bpSurfaceArea);
box.add(bpVolume);
leftPanel.add(box);

add(leftPanel);
add(rightPanel);
}

public void actionPerformed(ActionEvent e) {

if (e.getSource() == resultButton) {
try {
double radius = Double.parseDouble(radiusTextField.getText());
double height = Double.parseDouble(highTextField.getText());
double area = Math.PI * radius *radius;
surfaceAreaTextField.setText(""+(Math.PI * 2 * radius * height + 2 * area));
volumeTextField.setText(""+area * height);
} catch (NumberFormatException e1) {
JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE);
}
}
else if (e.getSource() == clearButton) {
radiusTextField.setText(" ");
highTextField.setText(" ");
}
}

public void focusLost(FocusEvent e) {
inputTextField = (JTextField)e.getSource();
}

public void focusGained(FocusEvent e) {}

public JTextField getInputTextField() {
return inputTextField;
}

}
```

###### 7，数字软键盘的实现（KeyJPanel.java）

```
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;

public class KeyJPanel extends JPanel implements ActionListener{

JButton[] keyButton = new JButton[12];
String[] num = {"1","2","3","4","5","6","7","8","9","0",".","BackSpace"};
AbstractPanel selectedPanel;
JTextField inputTextField;

public KeyJPanel(AbstractPanel selectedPanel) {
this.selectedPanel = selectedPanel;

Border lb = BorderFactory.createLineBorder(Color.gray, 2);
setBorder(lb);

setLayout(new GridLayout(4,3));

for (int i = 0; i < 12; i++) {
keyButton[i] = new JButton(num[i]);
keyButton[i].setFont(new Font("Arial",Font.BOLD,15));
keyButton[i].setForeground(Color.BLACK);
keyButton[i].addActionListener(this);
add(keyButton[i]);
}

}

public void actionPerformed(ActionEvent e) {
JButton button = (JButton)e.getSource();

inputTextField = selectedPanel.getInputTextField();

inputNumber(inputTextField,button);
}

private void inputNumber(JTextField tf, JButton button) {
String oldString = tf.getText();
if (oldString == null) {
tf.setText(" ");
}
String subStr = oldString.substring(0,oldString.length() -1);

String newString = button.getText();

if (newString.equals("BackSpace")) {
tf.setText(subStr);
}

else if (newString.equals(".")) {
tf.setText(oldString+".");
}

else {
tf.setText(oldString+newString);
}
}

}
```

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最后修改：2021 年 08 月 12 日

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2 条评论


July 3rd, 2019 at 09:17 am

太方便了

回复
nightcrawler7
June 11th, 2019 at 10:34 am

在吗？一起cyberpunk 2077

回复

Java几何计算器案例代码

君若 • 2019 年 06 月 07 日

成果截图
</div>![](https://jrboy.oss-cn-chengdu.aliyuncs.com/wp-content/uploads/2019/06/2019060715114862-300x200.png)![](https://jrboy.oss-cn-chengdu.aliyuncs.com/wp-content/uploads/2019/06/2019060715120368-300x200.png)<div class="tip inlineBlock success">

代码展示
</div>###### 1，程序主窗体代码（CalculatorWindow.java）``` 
import java.awt.BorderLayout; 
import java.awt.CardLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.ItemEvent; 
import java.awt.event.ItemListener;import javax.swing.ImageIcon; 
import javax.swing.JButton; 
import javax.swing.JComboBox; 
import javax.swing.JFrame; 
import javax.swing.JMenu; 
import javax.swing.JMenuBar; 
import javax.swing.JMenuItem; 
import javax.swing.JPanel;public class CalculatorWindow extends JFrame implements ActionListener,ItemListener {	CardLayout mycard; 
	JPanel controPanel,pCenter; 
	JComboBox chooseList; 
	JMenuBar menuBar; 
	JMenu menu; 
	JMenuItem mainWindow,exit;	public CalculatorWindow(){ 
		setTitle("常见几何图形计算器");		menuBar = new JMenuBar(); 
		menu = new JMenu("操作"); 
		mainWindow = new JMenuItem("主界面"); 
		mainWindow.addActionListener(this); 
		exit = new JMenuItem("退出"); 
		exit.addActionListener(this); 
		menu.add(mainWindow); 
		menu.add(exit); 
		menuBar.add(menu); 
		setJMenuBar(menuBar);		mycard = new CardLayout(); 
		pCenter = new JPanel(); 
		pCenter.setLayout(mycard); 
		add(pCenter,"Center");		controPanel = new JPanel(); 
		controPanel.setLayout(new BorderLayout());		chooseList = new JComboBox(); 
		chooseList.addItem("请点击下拉列表选择"); 
		chooseList.addItem("矩形的基本计算"); 
		chooseList.addItem("圆的基本计算"); 
		chooseList.addItem("三角形的基本计算"); 
		chooseList.addItem("圆柱的基本计算"); 
		chooseList.addItemListener(this);		ImageIcon icon = new ImageIcon(图片地址); 
		JButton imageButton = new JButton(icon);		controPanel.add(imageButton,"Center"); 
		controPanel.add(chooseList,"North");		pCenter.add("0",controPanel); 
		pCenter.add("1",new RectanglePanel()); 
		pCenter.add("2",new CirclePanel()); 
		pCenter.add("3",new TrianglePanel()); 
		pCenter.add("4",new CylinderPanel());		setBounds(100, 100, 700, 300); 
		setResizable(false); 
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
		setVisible(true);	}	public void itemStateChanged(ItemEvent e) { 
		int index = chooseList.getSelectedIndex(); 
		String choice = String.valueOf(index); 
		mycard.show(pCenter, choice);	}	public void actionPerformed(ActionEvent e) { 
		if (e.getSource() == mainWindow) { 
			mycard.first(pCenter); 
			chooseList.setSelectedIndex(0); 
		} 
		else if (e.getSource() == exit) { 
			System.exit(0); 
		} 
	}	public static void main(String[] args) { 
		new CalculatorWindow(); 
	}} 
```###### 2，BoxPanel.java和AbstractPanel.java的实现``` 
//代码（BoxPanel.java）import java.awt.Font;import javax.swing.Box; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.JTextField;public class BoxPanel extends JPanel{ 
	JTextField text;	public BoxPanel(String s,int n) {		Box box = Box.createHorizontalBox(); 
		box.add(new JLabel(s)); 
		text = new JTextField(" ",n);		text.setHorizontalAlignment(JTextField.RIGHT);		text.setFont(new Font("Arial",Font.BOLD,15)); 
		box.add(text); 
		add(box);	} 
	public JTextField getJTextField() { 
		return text; 
	} 
}//代码（AbstractPanel.java）import javax.swing.JPanel; 
import javax.swing.JTextField;public abstract class AbstractPanel extends JPanel { 
	public abstract JTextField getInputTextField(); 
} 
```###### 3，矩形计算器的实现（RectanglePanel.java）``` 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.FocusEvent; 
import java.awt.event.FocusListener;import javax.swing.Box; 
import javax.swing.JButton; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JTextField;public class RectanglePanel extends AbstractPanel implements ActionListener,FocusListener{	JButton resultButton,clearButton; 
	JPanel leftPanel,rightPanel,buttonPanel; 
	JTextField widthTextField,heightTextField; 
	JTextField lengthTextField,areaTextField,inputTextField; 
	BoxPanel bpWidth,bpHeight,bpLength,bpArea;	public RectanglePanel() { 
		setLayout(new GridLayout(1,2)); 
		rightPanel = new KeyJPanel(this); 
		leftPanel = new JPanel();		Box box = Box.createVerticalBox(); 
		bpWidth = new BoxPanel("请输入矩形的宽", 10); 
		widthTextField = bpWidth.getJTextField();		widthTextField.addFocusListener(this); 
		bpHeight = new BoxPanel("请输入矩形的高",10); 
		heightTextField = bpHeight.getJTextField(); 
		heightTextField.addFocusListener(this); 
		buttonPanel = new JPanel(); 
		resultButton = new JButton("计算结果");		resultButton.addActionListener(this); 
		clearButton = new JButton("清空"); 
		clearButton.addActionListener(this); 
		buttonPanel.add(resultButton); 
		buttonPanel.add(clearButton); 
		bpLength = new BoxPanel("矩形的周长：", 20); 
		lengthTextField = bpLength.getJTextField(); 
		bpArea = new BoxPanel("矩形的面积：",20); 
		this.areaTextField = this.bpArea.getJTextField();		box.add(bpWidth); 
		box.add(bpHeight); 
		box.add(buttonPanel); 
		box.add(bpLength); 
		box.add(bpArea); 
		leftPanel.add(box);		add(leftPanel); 
		add(rightPanel); 
	}	public void actionPerformed(ActionEvent e) {		if (e.getSource() == resultButton) { 
			try { 
				double width = Double.parseDouble(widthTextField.getText()); 
				double height = Double.parseDouble(heightTextField.getText()); 
				lengthTextField.setText(""+2*(width + height)); 
				areaTextField.setText(""+width*height); 
			} catch (NumberFormatException e1) {				JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE); 
			} 
		}		else if (e.getSource() == clearButton) { 
			widthTextField.setText(" "); 
			heightTextField.setText(" "); 
		} 
	}	public void focusGained(FocusEvent e) { 
		inputTextField = (JTextField)e.getSource(); 
	}	public void focusLost(FocusEvent e) {}	public JTextField getInputTextField() { 
		return inputTextField; 
	}} 
```###### 4，圆计算器的实现（CirclePanel.java）``` 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.FocusEvent; 
import java.awt.event.FocusListener;import javax.swing.Box; 
import javax.swing.JButton; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JTextField;public class CirclePanel extends AbstractPanel implements ActionListener,FocusListener{	JButton resultButton,clearButton; 
	JPanel leftPanel,rightPanel,buttonPanel; 
	JTextField radiusTextField; 
	JTextField lengthTextField,areaTextField,inputTextField; 
	BoxPanel bpRadius,bpLength,bpArea;	public CirclePanel() { 
		setLayout(new GridLayout(1,2)); 
		rightPanel = new KeyJPanel(this); 
		leftPanel =new JPanel();		Box box = Box.createVerticalBox(); 
		bpRadius = new BoxPanel("请输入圆的半径：", 10); 
		radiusTextField = bpRadius.getJTextField();		radiusTextField.addFocusListener(this); 
		buttonPanel = new JPanel(); 
		resultButton = new JButton("计算结果：");		resultButton.addActionListener(this); 
		clearButton = new JButton("清空"); 
		clearButton.addActionListener(this); 
		buttonPanel.add(resultButton); 
		buttonPanel.add(clearButton); 
		bpLength = new BoxPanel("圆的周长：", 20); 
		lengthTextField = bpLength.getJTextField(); 
		bpArea = new BoxpPanel("圆的面积：", 20); 
		areaTextField = bpArea.getJTextField();		box.add(bpRadius); 
		box.add(buttonPanel); 
		box.add(bpLength); 
		box.add(bpArea); 
		leftPanel.add(box);		add(leftPanel); 
		add(rightPanel); 
	}	public void actionPerformed(ActionEvent e) {		if (e.getSource() == resultButton) { 
			try { 
				double radius = Double.parseDouble(radiusTextField.getText()); 
				lengthTextField.setText(""+2*Math.PI*radius); 
				areaTextField.setText(""+Math.PI*radius*radius); 
			} catch (NumberFormatException e1) { 
				JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE); 
			} 
		} 
		else if (e.getSource() == clearButton) { 
			radiusTextField.setText(" "); 
		} 
	}	public void focusGained(FocusEvent e) { 
		inputTextField = (JTextField)e.getSource(); 
	}	public void focusLost(FocusEvent e) {}	public JTextField getInputTextField() { 
		return inputTextField; 
	}} 
```###### 5，三角形计算器的实现（TrianglePanel.java）``` 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.FocusEvent; 
import java.awt.event.FocusListener;import javax.swing.Box; 
import javax.swing.JButton; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JTextField;public class TrianglePanel extends AbstractPanel implements ActionListener,FocusListener{	JButton resultButton,clearButton; 
	JPanel leftPanel,rightPanel,buttonPanel; 
	JTextField sideATextField,sideBTextField,sideCTextField; 
	JTextField lengthTextField,areaTextField,inputTextField; 
	BoxPanel bpSideA,bpSideB,bpSideC,bpLength,bpArea;	public TrianglePanel() { 
		setLayout(new GridLayout(1,2)); 
		rightPanel = new KeyJPanel(this); 
		leftPanel =new JPanel();		Box box = Box.createVerticalBox(); 
		bpSideA = new BoxPanel("请输入三角形的边A：",10); 
		sideATextField = bpSideA.getJTextField();		sideATextField.addFocusListener(this); 
		bpSideB = new BoxPanel("请输入三角形的边B：",10); 
		sideBTextField = bpSideB.getJTextField(); 
		sideBTextField.addFocusListener(this); 
		bpSideC = new BoxPanel("请输入三角形的边C：",10); 
		sideCTextField = bpSideC.getJTextField(); 
		sideCTextField.addFocusListener(this); 
		buttonPanel = new JPanel(); 
		resultButton = new JButton("计算结果：");		resultButton.addActionListener(this); 
		clearButton = new JButton("清空"); 
		clearButton.addActionListener(this); 
		buttonPanel.add(resultButton); 
		buttonPanel.add(clearButton);		bpLength = new BoxPanel("三角形的周长：", 20); 
		lengthTextField = bpLength.getJTextField(); 
		bpArea = new BoxPanel("三角形的面积：", 20); 
		areaTextField = bpArea.getJTextField();		box.add(bpSideA); 
		box.add(bpSideB); 
		box.add(bpSideC); 
		box.add(buttonPanel); 
		box.add(bpLength); 
		box.add(bpArea); 
		leftPanel.add(box);		add(leftPanel); 
		add(rightPanel); 
	}	public void actionPerformed(ActionEvent e) {		if (e.getSource() == resultButton) { 
			try { 
				double sideA = Double.parseDouble(sideATextField.getText()); 
				double sideB = Double.parseDouble(sideBTextField.getText()); 
				double sideC = Double.parseDouble(sideCTextField.getText());				if ((sideA + sideB>sideC)&&(sideA + sideC>sideB)&&(sideB + sideC>sideA)) { 
					double p = (sideA + sideB +sideC)/2.0; 
					lengthTextField.setText("" + 2 * p); 
					double area = Math.sqrt(p * (p - sideA) * (p - sideB) *(p - sideC)); 
					areaTextField.setText("" + area); 
				} 
				else { 
					JOptionPane.showMessageDialog(this, "这不构成一个三角形，请重新输入三边","警告对话框",JOptionPane.WARNING_MESSAGE); 
				} 
			} catch (NumberFormatException e1) { 
				JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE); 
			} 
		} 
		else if (e.getSource() == clearButton) { 
			sideATextField.setText(" "); 
			sideBTextField.setText(" "); 
			sideCTextField.setText(" "); 
		} 
	}	public void focusGained(FocusEvent e) { 
		inputTextField = (JTextField)e.getSource(); 
	}	public void focusLost(FocusEvent e) {}	public JTextField getInputTextField() { 
		return inputTextField; 
	}} 
```###### 6，圆柱计算器的实现（CylinderPanel.java）``` 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.FocusEvent; 
import java.awt.event.FocusListener;import javax.swing.Box; 
import javax.swing.JButton; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JTextField;public class CylinderPanel extends AbstractPanel implements ActionListener,FocusListener{	JButton resultButton,clearButton; 
	JPanel leftPanel,rightPanel,buttonPanel; 
	JTextField radiusTextField,highTextField; 
	JTextField surfaceAreaTextField,volumeTextField,inputTextField; 
	BoxPanel bpRadius,bpHeight,bpSurfaceArea,bpVolume;	public CylinderPanel() { 
		setLayout(new GridLayout(1,2)); 
		rightPanel = new KeyJPanel(this); 
		leftPanel =new JPanel();		Box box = Box.createVerticalBox(); 
		bpRadius = new BoxPanel("请输入圆柱的底面半径：", 10); 
		radiusTextField = bpRadius.getJTextField(); 
		radiusTextField.addFocusListener(this); 
		bpHeight = new BoxPanel("请输入圆柱的高：", 10); 
		highTextField = bpHeight.getJTextField(); 
		highTextField.addFocusListener(this); 
		buttonPanel = new JPanel(); 
		resultButton = new JButton("计算结果："); 
		resultButton.addActionListener(this); 
		clearButton = new JButton("清空"); 
		clearButton.addActionListener(this); 
		buttonPanel.add(resultButton); 
		buttonPanel.add(clearButton); 
		bpSurfaceArea = new BoxPanel("圆柱的表面积：", 20); 
		this.surfaceAreaTextField = this.bpSurfaceArea.getJTextField(); 
		bpVolume = new BoxPanel("圆柱的体积：", 20); 
		this.volumeTextField = this.bpVolume.getJTextField(); 
		box.add(bpRadius); 
		box.add(bpHeight); 
		box.add(buttonPanel); 
		box.add(bpSurfaceArea); 
		box.add(bpVolume); 
		leftPanel.add(box);		add(leftPanel); 
		add(rightPanel); 
	}	public void actionPerformed(ActionEvent e) {		if (e.getSource() == resultButton) { 
			try { 
				double radius = Double.parseDouble(radiusTextField.getText()); 
				double height = Double.parseDouble(highTextField.getText()); 
				double area = Math.PI * radius *radius; 
				surfaceAreaTextField.setText(""+(Math.PI * 2 * radius * height + 2 * area)); 
				volumeTextField.setText(""+area * height); 
			} catch (NumberFormatException e1) { 
				JOptionPane.showMessageDialog(this, "请输入数字：","警告对话框",JOptionPane.WARNING_MESSAGE); 
			} 
		} 
		else if (e.getSource() == clearButton) { 
			radiusTextField.setText(" "); 
			highTextField.setText(" "); 
		} 
	}	public void focusLost(FocusEvent e) { 
		inputTextField = (JTextField)e.getSource(); 
	}	public void focusGained(FocusEvent e) {}	public JTextField getInputTextField() { 
		return inputTextField; 
	}} 
```###### 7，数字软键盘的实现（KeyJPanel.java）``` 
import java.awt.Color; 
import java.awt.Font; 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener;import javax.swing.BorderFactory; 
import javax.swing.JButton; 
import javax.swing.JPanel; 
import javax.swing.JTextField; 
import javax.swing.border.Border;public class KeyJPanel extends JPanel implements ActionListener{	JButton[] keyButton = new JButton[12]; 
	String[] num = {"1","2","3","4","5","6","7","8","9","0",".","BackSpace"}; 
	AbstractPanel selectedPanel; 
	JTextField inputTextField;	public KeyJPanel(AbstractPanel selectedPanel) { 
		this.selectedPanel = selectedPanel;		Border lb = BorderFactory.createLineBorder(Color.gray, 2); 
		setBorder(lb);		setLayout(new GridLayout(4,3));		for (int i = 0; i < 12; i++) { 
			keyButton[i] = new JButton(num[i]); 
			keyButton[i].setFont(new Font("Arial",Font.BOLD,15)); 
			keyButton[i].setForeground(Color.BLACK); 
			keyButton[i].addActionListener(this); 
			add(keyButton[i]); 
		}	}	public void actionPerformed(ActionEvent e) { 
		JButton button = (JButton)e.getSource();		inputTextField = selectedPanel.getInputTextField();		inputNumber(inputTextField,button); 
	}	private void inputNumber(JTextField tf, JButton button) { 
		String oldString = tf.getText(); 
		if (oldString == null) { 
			tf.setText(" "); 
		} 
		String subStr = oldString.substring(0,oldString.length() -1);		String newString = button.getText();		if (newString.equals("BackSpace")) { 
			tf.setText(subStr); 
		}		else if (newString.equals(".")) { 
			tf.setText(oldString+"."); 
		}		else { 
			tf.setText(oldString+newString); 
		} 
	}} 
```<hr class="content-copyright" style="margin-top:50px" /><blockquote class="content-copyright" style="font-style:normal">版权属于：君若(QQ:1813774883)本文链接：<a class="content-copyright" href="https://jrboy.cn/29.html">https://jrboy.cn/29.html</a>转载时须注明出处及本声明</blockquote>

Java几何计算器案例代码

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Java几何计算器案例代码

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