文件名称：模拟时钟StillClock类
文件大小：3KB
文件格式：JAVA
更新时间：2015-12-02 04:24:08
StillClock StillClock() StillClock类 模拟时钟 Still
Java基础篇中的StillClock类用于画出时钟以方便Java进阶篇P228第二十九章多线程（第八版）ClockWithAudio类的调用。 package 多线程练习; import java.awt.*; import javax.swing.*; import java.util.*; public class StillClock extends JPanel { private int hour; private int minute; private int second; /** Construct a default clock with the current time */ public StillClock() { setCurrentTime(); } /** Construct a clock with specified hour, minute, and second */ public StillClock(int hour, int minute, int second) { this.hour = hour; this.minute = minute; this.second = second; } /** Return hour */ public int getHour() { return hour; } /** Set a new hour */ public void setHour(int hour) { this.hour = hour; repaint(); } /** Return minute */ public int getMinute() { return minute; } /** Set a new minute */ public void setMinute(int minute) { this.minute = minute; repaint(); } /** Return second */ public int getSecond() { return second; } /** Set a new second */ public void setSecond(int second) { this.second = second; repaint(); } /** Draw the clock */ protected void paintComponent(Graphics g) { super.paintComponent(g); // Initialize clock parameters int clockRadius = (int) (Math.min(getWidth(), getHeight()) * 0.8 * 0.5); int xCenter = getWidth() / 2; int yCenter = getHeight() / 2; // Draw circle g.setColor(Color.black); g.drawOval(xCenter - clockRadius, yCenter - clockRadius, 2 * clockRadius, 2 * clockRadius); g.drawString("12", xCenter - 5, yCenter - clockRadius + 12); g.drawString("9", xCenter - clockRadius + 3, yCenter + 5); g.drawString("3", xCenter + clockRadius - 10, yCenter + 3); g.drawString("6", xCenter - 3, yCenter + clockRadius - 3); // Draw second hand int sLength = (int) (clockRadius * 0.8); int xSecond = (int) (xCenter + sLength * Math.sin(second * (2 * Math.PI / 60))); int ySecond = (int) (yCenter - sLength * Math.cos(second * (2 * Math.PI / 60))); g.setColor(Color.red); g.drawLine(xCenter, yCenter, xSecond, ySecond); // Draw minute hand int mLength = (int) (clockRadius * 0.65); int xMinute = (int) (xCenter + mLength * Math.sin(minute * (2 * Math.PI / 60))); int yMinute = (int) (yCenter - mLength * Math.cos(minute * (2 * Math.PI / 60))); g.setColor(Color.blue); g.drawLine(xCenter, yCenter, xMinute, yMinute); // Draw hour hand int hLength = (int) (clockRadius * 0.5); int xHour = (int) (xCenter + hLength * Math.sin((hour % 12 + minute / 60.0) * (2 * Math.PI / 12))); int yHour = (int) (yCenter - hLength * Math.cos((hour % 12 + minute / 60.0) * (2 * Math.PI / 12))); g.setColor(Color.BLACK); g.drawLine(xCenter, yCenter, xHour, yHour); } public void setCurrentTime() { // Construct a calendar for the current date and time Calendar calendar = new GregorianCalendar(); // Set current hour, minute and second this.hour = calendar.get(Calendar.HOUR_OF_DAY); this.minute = calendar.get(Calendar.MINUTE); this.second = calendar.get(Calendar.SECOND); } public Dimension getPreferredSize() { return new Dimension(200, 200); } }