java实现几何图形计算（Java实现规则几何图形问题求解）
来学习Java基础练习小项目啦！
随着计算机的发展，人们对图形的计算要求会越来越高。在各行各业中的计算人员会对图形的计算有便利的要求，规则几何图形问题求解程序应运而生！
本程序开发使用的IDE是idea！
1.程序采用文件流操作将数据存储到.txt文件中，文件的路径是 d:\\xxx.txt 。
2.文件中存储了基本的数据，包括输入的规则几何图形的长宽高等数据，还包括计算得到的面积周长等数据！例如：
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.*;
public class Circleplay {
public static void main(String args[]){
WindowCircle circleplay = new WindowCircle();
circleplay.setTitle("几何图形计算");
circleplay.setSize(500,300);
circleplay.setLocation(500,250);
}
}
class WindowCircle extends JFrame {
Circle circle; // 数据对象
JTextField textA, textB, textC; // 数据对象的视图
JTextArea showArea; // 数据对象的视图
JButton controlButton1; // 控制器对象
JButton controlButton2;
WindowCircle() {
init();
setVisible(true);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
void init() {
circle = new Circle();
textA = new JTextField(5);
textB = new JTextField(5);
showArea = new JTextArea();
controlButton1 = new JButton("计算");
controlButton2 = new JButton("退出");
JPanel pNorth = new JPanel();
JPanel pNorth1 = new JPanel();
pNorth.add(new JLabel("半径"));
pNorth.add(textA);
pNorth.add(controlButton1);
pNorth.add(controlButton2);
pNorth.setLocation(250,250);
pNorth1.add(new JLabel("图形线条粗细"));
String[] s1 = new String[]{
"1","2","3","4","5","6","7","8","9"};
final JComboBox<String> comboBox1 = new JComboBox<String>(s1);
pNorth1.add(comboBox1);
pNorth1.add(new JLabel("图形线条颜色"));
String[] s2 = new String[]{
"黑色","红色","灰色","蓝色","黄色","绿色","紫色"};
final JComboBox<String> comboBox2 = new JComboBox<String>(s2);
pNorth1.add(comboBox2);
add(pNorth, BorderLayout.NORTH);
pNorth1.setPreferredSize(new Dimension(90,150));
add(pNorth1, BorderLayout.WEST);
add(new JScrollPane(showArea), BorderLayout.CENTER);
controlButton1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
try {
double a = Double.parseDouble(textA.getText().trim()); //
circle.setA(a); // 更新数据
circle.paint();
String area1 = circle.getlength();
String area2 = circle.getArea();
showArea.append("半径为" a "的圆" " " "周长为:" area1 " " "面积为:" area2 "\n");
} catch (Exception ex) {
showArea.append("\n" ex "\n");
}
}});
controlButton2.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
dispose();
}});
comboBox1.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED) {
circle.Line(comboBox1.getSelectedIndex() 1);
circle.paint();
}
}});
comboBox2.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED) {
circle.Colour(comboBox2.getSelectedIndex() 1);
circle.paint();
}
}});
}}
class Circle {
FileWriter dout;
double sideA, sideB, area,p;
int line = 1,colournumber = 1;
public void setA(double a) {
sideA = a;
}
public String getArea() {
area = 3.14*sideA*sideA;
return String.valueOf(area); // Double.toString(area)
}
public String getlength() {
p = 3.14 * sideA;
return String.valueOf(p);
}
public void Line(int line)
{
this.line = line;
}
public void Colour(int colournumber)
{
this.colournumber = colournumber;
}
public void paint(){
try{
dout = new FileWriter("d:\\Circle.txt");
}catch(IOException e){
}
JFrame jFrame = new JFrame("圆的图形");
// 创建画板
JPanel jpanel = new JPanel() {
public void paint(Graphics graphics) {
// 必须先调用父类的paint方法
super.paint(graphics);
Graphics2D g=(Graphics2D) graphics.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if(colournumber == 1)
g.setColor(Color.BLACK);
else if(colournumber == 2)
g.setColor(Color.RED);
else if(colournumber == 3)
g.setColor(Color.GRAY);
else if(colournumber == 4)
g.setColor(Color.BLUE);
else if(colournumber == 5)
g.setColor(Color.YELLOW);
else if(colournumber == 6)
g.setColor(Color.GREEN);
else if(colournumber == 7)
g.setColor(Color.magenta);
if(line == 1){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 2){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 3){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 4){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 5){
try{
dout.write("长方形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 6){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 7){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 8){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(line == 9){
try{
dout.write("圆形线条粗细为");
dout.write(String.valueOf(line));
dout.write(" \r\n");
}catch(IOException a){
}
}
if(colournumber == 1)
{
g.setColor(Color.BLACK);
try{
dout.write("圆形颜色为");
dout.write("黑色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 2)
{
g.setColor(Color.RED);
try{
dout.write("圆形颜色为");
dout.write("红色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 3)
{
g.setColor(Color.GRAY);
try{
dout.write("圆形颜色为");
dout.write("灰色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 4)
{
g.setColor(Color.BLUE);
try{
dout.write("圆形颜色为");
dout.write("蓝色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 5)
{
g.setColor(Color.YELLOW);
try{
dout.write("圆形颜色为");
dout.write("黄色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 6)
{
g.setColor(Color.GREEN);
try{
dout.write("圆形颜色为");
dout.write("绿色");
dout.write(" \r\n");
}catch(IOException e){
}
}
else if(colournumber == 7)
{
g.setColor(Color.magenta);
try{
dout.write("圆形颜色为");
dout.write("紫色");
dout.write(" \r\n");
}catch(IOException e){
}
}
Stroke stroke=new BasicStroke(line);
g.setStroke(stroke);
DecimalFormat df = new DecimalFormat("######0");
String str1 = df.format(sideA);
int a = Integer.parseInt(str1);
g.drawOval(100, 50, a*10,a*10);
try{
dout.write("圆形半径为");
dout.write(String.valueOf(a));
dout.write(" \r\n");
dout.write("圆形周长为");
dout.write(String.valueOf(p));
dout.write(" \r\n");
dout.write("圆形面积为");
dout.write(String.valueOf(area));
dout.write(" \r\n");
dout.close();
}catch(IOException exa){
}
}
};
jFrame.add(jpanel);
// 设置画框大小（宽度，高度），默认都为0
jFrame.setSize(300, 300);
// 将画框展示出来。true设置可见，默认为false隐藏
jFrame.setVisible(true);
jFrame.setLocation(1000,250);
}
}
以下是项目结构的展示：
规则几何图形求解根据图形的某些特征设置输入参数，根据这些参数来计算相应图形的面积和周长。在绘制图形方面，是根据所输入的参数来确定坐标，再连接坐标形成的图形。在改变图形方面，用绘图的类型去改变图形。
这个程序适合在新手学习完Java基础知识以后练习，可以加深对Java编程的理解，同时对Java流的操作这一个抽象的概念有了更加深入的理解，学习完GUI技术不仅提升了编程兴趣，同时为Java下一阶段的学习奠定了基础。
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