本文实例为大家分享了java实现时钟效果的具体代码，供大家参考，具体内容如下

实现效果如图：

Java代码：

文件一：ClockPanel.java

import static java.util.Calendar.HOUR;

import static java.util.Calendar.MILLISECOND;

import static java.util.Calendar.MINUTE;

import static java.util.Calendar.SECOND;

import java.awt.BasicStroke;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.util.Calendar;

import javax.swing.ImageIcon;

import javax.swing.JPanel;

/**

* 时钟面板

*

* @author 听说你很会玩

*/

@SuppressWarnings("serial")

public class ClockPanel extends JPanel {

// 3个指针的粗细

private static final BasicStroke HOURS_POINT_WIDTH = new BasicStroke(4);

private static final BasicStroke MINUETES_POINT_WIDTH = new BasicStroke(3);

private static final BasicStroke SEC_POINT_WIDTH = new BasicStroke(2);

ImageIcon background;// 背景图片对象

private int centerX;// 中心坐标

private int centerY;// 中心坐标

private final static int secLen = 60; // 指针长度

private final static int minuesLen = 55; // 指针长度

private final static int hoursLen = 36; // 指针长度

/**

* 构造方法

*/

public ClockPanel() {

setToolTipText("小键盘+、-调整透明度，Crtl+Shift+X退出");// 提示信息

setOpaque(false);

background = new ImageIcon(getClass().getResource("clock.jpg"));// 加载图片

int iconWidth = background.getIconWidth();// 获取图片大小

centerX = iconWidth / 2;// 获取图片中间坐标

int iconHeight = background.getIconHeight();

centerY = iconHeight / 2;// 获取图片中间坐标

setPreferredSize(new Dimension(iconWidth, iconHeight));

}

@Override

public void paint(Graphics g) {// 重写父类方法

Graphics2D g2 = (Graphics2D) g;

g2.drawImage(background.getImage(), 0, 0, this);// 绘制背景图片

Calendar calendar = Calendar.getInstance();// 获取日历对象

int millisecond = calendar.get(MILLISECOND);// 获取毫秒值

int sec = calendar.get(SECOND);// 获取秒值

int minutes = calendar.get(MINUTE);// 获取分值

int hours = calendar.get(HOUR);// 获取时值

double secAngle = (60 - sec) * 6 - (millisecond / 150); // 秒针角度

int minutesAngle = (60 - minutes) * 6;// 分针角度

int hoursAngle = (12 - hours) * 360 / 12 - (minutes / 2);// 时针角度

// 计算秒针、分针、时针指向的坐标

int secX = (int) (secLen * Math.sin(Math.toRadians(secAngle)));// 秒针指向点的X坐标

int secY = (int) (secLen * Math.cos(Math.toRadians(secAngle))); // 秒针指向点的Y坐标

int minutesX = (int) (minuesLen * Math

.sin(Math.toRadians(minutesAngle))); // 分针指向点的X坐标

int minutesY = (int) (minuesLen * Math

.cos(Math.toRadians(minutesAngle))); // 分针指向点的Y坐标

int hoursX = (int) (hoursLen * Math.sin(Math.toRadians(hoursAngle))); // 时针指向点的X坐标

int hoursY = (int) (hoursLen * Math.cos(Math.toRadians(hoursAngle))); // 时针指向点的Y坐标

// 分别绘制时针、分针、秒针

g2.setStroke(HOURS_POINT_WIDTH);// 设置时针的宽度

g2.setColor(Color.BLACK);// 设置时针的颜色

g2.drawLine(centerX, centerY, centerX - hoursX, centerY - hoursY);// 绘制时针

g2.setStroke(MINUETES_POINT_WIDTH);// 设置分针的宽度

if (minutesAngle != hoursAngle) // 分针、时针重叠变色

g2.setColor(new Color(0x2F2F2F));// 设置未重叠时的颜色

else {

g2.setColor(Color.GREEN);// 设置重叠时的颜色

}

g2.drawLine(centerX, centerY, centerX - minutesX, centerY - minutesY);// 绘制分针

g2.setStroke(SEC_POINT_WIDTH);// 设置秒针的宽度

if (secAngle != hoursAngle && secAngle != minutesAngle)// 分针、时针、秒针重叠变色

g2.setColor(Color.ORANGE);// 设置未重叠时的颜色

else {

g2.setColor(Color.GREEN);// 设置重叠时的颜色

}

// 绘制3个指针的中心圆和秒针

g2.fillOval(centerX - 5, centerY - 5, 10, 10);// 绘制中心圆

g2.drawLine(centerX, centerY, centerX - secX, centerY - secY);// 绘制秒针

g2.drawLine(centerX + 1, centerY + 1, centerX - secX + 1, centerY

- secY + 1);// 绘制秒针

}

}