Java画图(直线，矩形，椭圆)，并显示其周长面积
Shape类 父类
package com.lovoinfo.shape;
import java.awt.Color;
import java.awt.Graphics;
/**
* 图形(抽象类，不能实例化)
* @author Administrator
*
*/
public abstract class Shape {
protected int startX,startY;//起点横纵坐标
protected int endX,endY;//终点横纵坐标
protected Color color;
public void setColor(Color color) {
this.color = color;
}
/**
* 绘图(抽象方法留给子类重写)
* @param g 画笔
*/
public abstract void draw(Graphics g);
public abstract void calculate(Graphics g);
public int getStartX() {
return startX;
}
public void setStartX(int startX) {
this.startX = startX;
}
public int getStartY() {
return startY;
}
public void setStartY(int startY) {
this.startY = startY;
}
public int getEndX() {
return endX;
}
public void setEndX(int endX) {
this.endX = endX;
}
public int getEndY() {
return endY;
}
public void setEndY(int endY) {
this.endY = endY;
}
}
定义子类
Rectangle
Oval
Line
package com.lovoinfo.shape;
import java.awt.Graphics;
public class Rectangle extends Shape {
private int width;
private int height;
private String s;
@Override
public void draw(Graphics g) {
g.setColor(color);
width= Math.abs(endX-startX);
height=Math.abs(endY-startY);
int x1=startXint y1=startY@Override
public void calculate(Graphics g) {
s="此图为矩形"+"矩形周长为："+2*(width+height)+"面积为："+width*height;
g.drawString(s, 100,100 );
}
}
package com.lovoinfo.shape;
import java.awt.Graphics;
public class Oval extends Shape{
private static final double PI = 3.14;
private String s;
private int width;
private int height;
@Override
public void draw(Graphics g) {
g.setColor(color);
width= Math.abs(endX-startX);
height=Math.abs(endY-startY);
int x1=startXint y1=startY@Override
public void calculate(Graphics g) {
double a=width/2;
double b=height/2;
s="此图为椭圆："+"面积为："+PI *a*b+"周长为："+2*PI*b+4*(Math.abs(a-b));
g.drawString(s, 100, 100);
}
}
package com.lovoinfo.shape;
import java.awt.Graphics;
public class Line extends Shape {
private String s;
@Override
public void draw(Graphics g) {
g.setColor(color);
g.drawLine(startX,startY, endX, endY);
}
@Override
public void calculate(Graphics g) {
s="此图为直线"+"长度为："+Math.sqrt((startX-endX)*(startX-endX)+
(startY-endY)*(startY-endY));
g.drawString(s, 100, 100);
}
}
工具类
产生直线椭圆矩形坐标随机数
package com.lovoinfo.util;
import java.awt.Color;
/**
* 工具类：第一：加上final，让这个类不能被继承
* 第二：构造器私有，让别人只能以对象加点调用方法
* @author Administrator
*
*/
public final class MyUtil {
private MyUtil(){
}
/**
* 产生指定范围的随机整数
* @param min 最小值（闭区间）
* @param max 最大值（闭区间）
* @return 指定范围的随机整数
*/
public static int random(int min,int max){
return (int) (Math.random()*(max-min+1)+min);
}
public static Color randomColor(){
int r=random(0,255);
int g=random(0,255);
int b=random(0,255);
return new Color(r,g,b);
}
}
UI
package com.lovoinfo.ui;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import com.lovoinfo.shape.Line;
import com.lovoinfo.shape.Oval;
import com.lovoinfo.shape.Rectangle;
import com.lovoinfo.shape.Shape;
import com.lovoinfo.util.MyUtil;
@SuppressWarnings("serial")
public class MyFrame extends JFrame {
private class ButtonHandler implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
if(command.equals("Line")){
shape=new Line();
}else if(command.equals("Oval")){
shape=new Oval();
}else{
shape=new Rectangle();
}
shape.setStartX(MyUtil.random(0, 1000));
shape.setStartY(MyUtil.random(0, 600));
shape.setEndX(MyUtil.random(0, 1000));
shape.setEndY(MyUtil.random(0, 600));
// shape.setColor(MyUtil.randomColor());
shape.setColor(Color.black);
repaint();
}
}
private JButton lineButton;
private JButton ovalButton;
private JButton recButton;
// private Line line = null;
// private Rectangle rec = null;
// private Oval oval = null;
private Shape shape=null;
public MyFrame() {
this.setSize(1000, 600);
this.setTitle("绘图窗口");
// super.setTitle("我的第一个窗口");
this.setResizable(false);
this.setLocationRelativeTo(null);// 窗口居中
this.setDefaultCloseOperation(EXIT_ON_CLOSE);// 设置默认的关闭操作
lineButton = new JButton("Line");
ovalButton = new JButton("Oval");
recButton = new JButton("Rectangle");
// recButton.addActionListener(new ActionListener() {
//
// @Override
// public void actionPerformed(ActionEvent e) {
// rec = new Rectangle();
// rec.setStartX(MyUtil.random(0, 1000));
// rec.setStartY(MyUtil.random(0, 600));
// rec.setEndX(MyUtil.random(0, 1000));
// rec.setEndY(MyUtil.random(0, 600));
// repaint();
//
// }
// });
// ovalButton.addActionListener(new ActionListener() {
//
// @Override
// public void actionPerformed(ActionEvent e) {
// oval = new Oval();
// oval.setStartX(MyUtil.random(0, 1000));
// oval.setStartY(MyUtil.random(0, 600));
// oval.setEndX(MyUtil.random(0, 1000));
// oval.setEndY(MyUtil.random(0, 600));
// repaint();
//
// }
// });
// lineButton.addActionListener(new ActionListener() {
// /**
// * 点击按钮后要执行的方法
// */
// @Override
// public void actionPerformed(ActionEvent e) {
//
// line = new Line();
// line.setStartX(MyUtil.random(0, 1000));
// line.setStartY(MyUtil.random(0, 600));
// line.setEndX(MyUtil.random(0, 1000));
// line.setEndY(MyUtil.random(0, 600));
//
// repaint();
// }
// });// 需要放一个Action监听器
ActionListener handler=new ButtonHandler();
lineButton.addActionListener(handler);
ovalButton.addActionListener(handler);
recButton.addActionListener(handler);
this.setLayout(new FlowLayout());// 设置流式布局管理器
this.add(lineButton);
this.add(ovalButton);
this.add(recButton);
}
@Override
public void paint(Graphics g) {
super.paint(g);
if(shape!=null){
shape.draw(g);
shape.calculate(g);
}
// if (line != null) {
// line.draw(g);
// }
// if (rec != null) {
// rec.draw(g);
// }
// if (oval != null) {
// oval.draw(g);
// }
}
}测试类
package com.lovoinfo.ui;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import com.lovoinfo.shape.Line;
import com.lovoinfo.shape.Oval;
import com.lovoinfo.shape.Rectangle;
import com.lovoinfo.shape.Shape;
import com.lovoinfo.util.MyUtil;
@SuppressWarnings("serial")
public class MyFrame extends JFrame {
private class ButtonHandler implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
if(command.equals("Line")){
shape=new Line();
}else if(command.equals("Oval")){
shape=new Oval();
}else{
shape=new Rectangle();
}
shape.setStartX(MyUtil.random(0, 1000));
shape.setStartY(MyUtil.random(0, 600));
shape.setEndX(MyUtil.random(0, 1000));
shape.setEndY(MyUtil.random(0, 600));
// shape.setColor(MyUtil.randomColor());
shape.setColor(Color.black);
repaint();
}
}
private JButton lineButton;
private JButton ovalButton;
private JButton recButton;
// private Line line = null;
// private Rectangle rec = null;
// private Oval oval = null;
private Shape shape=null;
public MyFrame() {
this.setSize(1000, 600);
this.setTitle("绘图窗口");
// super.setTitle("我的第一个窗口");
this.setResizable(false);
this.setLocationRelativeTo(null);// 窗口居中
this.setDefaultCloseOperation(EXIT_ON_CLOSE);// 设置默认的关闭操作
lineButton = new JButton("Line");
ovalButton = new JButton("Oval");
recButton = new JButton("Rectangle");
// recButton.addActionListener(new ActionListener() {
//
// @Override
// public void actionPerformed(ActionEvent e) {
// rec = new Rectangle();
// rec.setStartX(MyUtil.random(0, 1000));
// rec.setStartY(MyUtil.random(0, 600));
// rec.setEndX(MyUtil.random(0, 1000));
// rec.setEndY(MyUtil.random(0, 600));
// repaint();
//
// }
// });
// ovalButton.addActionListener(new ActionListener() {
//
// @Override
// public void actionPerformed(ActionEvent e) {
// oval = new Oval();
// oval.setStartX(MyUtil.random(0, 1000));
// oval.setStartY(MyUtil.random(0, 600));
// oval.setEndX(MyUtil.random(0, 1000));
// oval.setEndY(MyUtil.random(0, 600));
// repaint();
//
// }
// });
// lineButton.addActionListener(new ActionListener() {
// /**
// * 点击按钮后要执行的方法
// */
// @Override
// public void actionPerformed(ActionEvent e) {
//
// line = new Line();
// line.setStartX(MyUtil.random(0, 1000));
// line.setStartY(MyUtil.random(0, 600));
// line.setEndX(MyUtil.random(0, 1000));
// line.setEndY(MyUtil.random(0, 600));
//
// repaint();
// }
// });// 需要放一个Action监听器
ActionListener handler=new ButtonHandler();
lineButton.addActionListener(handler);
ovalButton.addActionListener(handler);
recButton.addActionListener(handler);
this.setLayout(new FlowLayout());// 设置流式布局管理器
this.add(lineButton);
this.add(ovalButton);
this.add(recButton);
}
@Override
public void paint(Graphics g) {
super.paint(g);
if(shape!=null){
shape.draw(g);
shape.calculate(g);
}
// if (line != null) {
// line.draw(g);
// }
// if (rec != null) {
// rec.draw(g);
// }
// if (oval != null) {
// oval.draw(g);
// }
}
}