动态演示 1~120 质数筛选
项目简介
本项目基于Java Swing图形界面开发,实现可视化质数筛选工具PrimeNumberSieve。程序在10行×12列网格中摆放1~120全部数字,通过延时动画逐个校验数值是否为素数,素数格子变红,合数填充随机配色,同时右侧文本框实时累加所有找到的质数,把抽象的素数判断算法转化为直观的动态画面。
项目用到技术:Swing窗口布局、GridLayout网格布局、SwingWorker子线程动画延时、高效素数判定算法、随机配色工具方法。
素数判定算法原理(分小点)
- 素数规则
(1)小于等于 1:非素数;
(2)2、3:是素数;
(3)能被 2、3 整除:非素数;
(4)从 i=5 开始,步长 + 6,校验i和i+2能否整除目标数,直到√n。 - 核心 isPrime 算法思路
区别暴力循环,该判定方式减少循环次数,优化大数判断效率,下文代码对应本逻辑
完整源码:
java
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class PrimeNumberSieve extends JFrame {
private static final int ROWS = 10;
private static final int COLS = 12;
private static final int TOTAL = ROWS * COLS; // 120
private static final int DELAY = 50; // 每个格子遍历延迟(毫秒)
private JPanel gridPanel;
private JPanel primeListPanel;
private JLabel[] numberLabels = new JLabel[TOTAL];
private JTextArea primeTextArea;
private List<Integer> primesFound = new ArrayList<>();
private Random random = new Random();
public PrimeNumberSieve() {
setTitle("Prime Numbers Visual Sieve");
setSize(900, 650);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setLayout(new BorderLayout(10, 10));
// 初始化网格面板 (10行12列)
gridPanel = new JPanel(new GridLayout(ROWS, COLS, 3, 3));
gridPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
gridPanel.setBackground(Color.WHITE);
// 创建120个格子,初始灰色
for (int i = 1; i <= TOTAL; i++) {
JLabel label = new JLabel(String.valueOf(i), SwingConstants.CENTER);
label.setOpaque(true);
label.setBackground(Color.GRAY);
label.setForeground(Color.BLACK);
label.setFont(new Font("Arial", Font.BOLD, 14));
label.setPreferredSize(new Dimension(60, 45));
Border border = BorderFactory.createLineBorder(Color.DARK_GRAY, 1);
label.setBorder(border);
numberLabels[i - 1] = label;
gridPanel.add(label);
}
// 右侧素数列表面板
primeListPanel = new JPanel(new BorderLayout());
primeListPanel.setBorder(BorderFactory.createTitledBorder("Prime numbers"));
primeListPanel.setBackground(Color.WHITE);
primeListPanel.setPreferredSize(new Dimension(200, 0));
primeTextArea = new JTextArea();
primeTextArea.setEditable(false);
primeTextArea.setFont(new Font("Monospaced", Font.PLAIN, 14));
primeTextArea.setBackground(Color.WHITE);
primeTextArea.setLineWrap(true);
primeTextArea.setWrapStyleWord(true);
JScrollPane scrollPane = new JScrollPane(primeTextArea);
scrollPane.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
primeListPanel.add(scrollPane, BorderLayout.CENTER);
// 添加到主窗口
add(gridPanel, BorderLayout.CENTER);
add(primeListPanel, BorderLayout.EAST);
// 开始遍历动画
startSieveAnimation();
}
private void startSieveAnimation() {
SwingWorker<Void, Integer> worker = new SwingWorker<>() {
@Override
protected Void doInBackground() throws Exception {
for (int i = 1; i <= TOTAL; i++) {
Thread.sleep(DELAY);
publish(i);
}
return null;
}
@Override
protected void process(List<Integer> chunks) {
for (int num : chunks) {
checkAndColorNumber(num);
}
}
@Override
protected void done() {
// 动画结束后,在控制台打印所有素数
System.out.println("=== 遍历完成 ===");
System.out.println("找到的素数总数: " + primesFound.size());
System.out.println("所有素数: " + primesFound);
// 也可以在 GUI 中弹窗提示
JOptionPane.showMessageDialog(
PrimeNumberSieve.this,
"筛法完成!共找到 " + primesFound.size() + " 个素数。\n请在控制台查看完整列表。",
"完成",
JOptionPane.INFORMATION_MESSAGE
);
}
};
worker.execute();
}
private void checkAndColorNumber(int num) {
JLabel label = numberLabels[num - 1];
if (isPrime(num)) {
// 素数 -> 红色
label.setBackground(Color.RED);
label.setForeground(Color.WHITE);
primesFound.add(num);
// 更新右侧素数列表显示
updatePrimeDisplay();
} else {
// 非素数 -> 随机颜色(排除红色和灰色,避免混淆)
Color randomColor = getRandomColor();
label.setBackground(randomColor);
label.setForeground(Color.BLACK);
}
}
private boolean isPrime(int n) {
if (n <= 1) return false;
if (n <= 3) return true;
if (n % 2 == 0 || n % 3 == 0) return false;
for (int i = 5; i * i <= n; i += 6) {
if (n % i == 0 || n % (i + 2) == 0) return false;
}
return true;
}
private Color getRandomColor() {
// 生成鲜艳的随机颜色,排除红色(素数专用)和灰色(初始色)
int r, g, b;
do {
r = random.nextInt(200) + 55; // 55-255
g = random.nextInt(200) + 55;
b = random.nextInt(200) + 55;
} while ((r > 200 && g < 100 && b < 100) || (r == g && g == b)); // 排除红色和灰色
return new Color(r, g, b);
}
private void updatePrimeDisplay() {
StringBuilder sb = new StringBuilder();
int count = 0;
for (int p : primesFound) {
sb.append(String.format("%4d", p));
count++;
if (count % 4 == 0) {
sb.append("\n");
} else {
sb.append(" ");
}
}
primeTextArea.setText(sb.toString());
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
new PrimeNumberSieve().setVisible(true);
});
}
}