java 小程序源代码
求素数，比较经典的，下面是代码及注释
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public class Sushu {
/**
* 判断一个数是不是素数
* @param a 被判断的数
* @return 是素数返回真
*/
public boolean isSuhu(int a){
boolean isSushu=true;
//根据素数的性质判断一个数是否为素数
for(int i=2;i<a;i++){
if(a%i==0){
isSushu=false;
break;
}
}
return isSushu;
}
/**
* 判断连续若干个数中那些是素数
* @param start 起始数
* @param end 终止数
*/
public void selectSushu(int start,int end){
//判断一串数中那些为素数，并将结果打印出来
for(int i=start;i<=end;i++){
if(isSuhu(i)){
System.out.println(i);
}
}
}
public static void main(String []args){
//定义起始位置和终止位置
int start=1;
int end=100;
//声明变量
Sushu s=new Sushu();
//调用方法
s.selectSushu(start, end);
}
}
求一个JAVA小程序的源代码，要求如下
大概是这个样子。
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import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DateCheck extends JFrame implements ActionListener {
private boolean isOval = true;
public DateCheck() {
setSize(567, 419);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
getContentPane().setLayout(null);
JButton btnNewButton = new JButton("Oval");
btnNewButton.addActionListener(this);
btnNewButton.setBounds(80, 10, 93, 23);
getContentPane().add(btnNewButton);
JButton btnNewButton_1 = new JButton("Rect");
btnNewButton_1.setBounds(203, 10, 93, 23);
btnNewButton_1.addActionListener(this);
getContentPane().add(btnNewButton_1);
JPanel panel = new MyPanel();
panel.setBounds(12, 47, 537, 337);
getContentPane().add(panel);
new Timer().schedule(new MyTimesk(), new Date(), 100);
setVisible(true);
}
public static void main(String[] args) {
new DateCheck();
}
public void actionPerformed(ActionEvent event) {
isOval = "Oval".equals(event.getActionCommand());
System.out.println(isOval);
}
class MyPanel extends JPanel implements MouseListener {
Point point1 = null;
Point point2 = null;
// protected void paintComponent(Graphics g) {
// super.paintComponent(g);
//
// }
int click = 0;
public MyPanel() {
addMouseListener(this);
}
public void paint(Graphics g) {
super.paint(g);
Point p = this.getMousePosition();
if (p == null && click % 2 == 1) {
return;
}
if (click % 2 == 0 && (point1 == null || point2 == null)) {
return;
}
if (click % 2 == 0) {
if (isOval) {
int w = point2.x - point1.x;
int h = point2.y - point1.y;
int r = (int) Math.sqrt(w * w + h * h);
g.drawOval(point1.x - r / 2, point1.y - r / 2, r + r / 2, r
+ r / 2);
} else {
g.drawRect(point1.x, point1.y, point2.x - point1.x,
point2.y - point1.y);
}
return;
}
if (isOval) {
if (click % 2 == 1) {
int w = p.x - point1.x;
int h = p.y - point1.y;
int r = (int) Math.sqrt(w * w + h * h);
g.drawOval(point1.x - r / 2, point1.y - r / 2, r + r / 2, r
+ r / 2);
}
} else {
g.drawRect(point1.x, point1.y, p.x - point1.x, p.y - point1.y);
}
}
public void mouseClicked(MouseEvent mouseevent) {
click++;
if (click % 2 == 1) {
point1 = mouseevent.getPoint();
} else {
point2 = mouseevent.getPoint();
}
}
public void mouseEntered(MouseEvent mouseevent) {
}
public void mouseExited(MouseEvent mouseevent) {
}
public void mousePressed(MouseEvent mouseevent) {
}
public void mouseReleased(MouseEvent mouseevent) {
}
}
class MyTimesk extends TimerTask {
public void run() {
repaint();
}
}
}
