11.1 数学Math类
实例186 求圆周率∏值
package Chapter11.math; public class CirclePI { /** * @param args */ public static void main(String[] args) { int n = 100000;// 投的点数 int m = 0;// 投中的个数 double x, y;// x和y坐标点 for (int i = 0; i < n; i++) { // 随机产生一个点 x = Math.random(); y = Math.random(); // 计算这个点是位于圆内还是圆外 if (x * x + y * y <= 1)// 判断掷入的这个点是不是在圆内 m++; } // 统计得到π的值 System.out.println("根据随机数计算π的结果如下:"); System.out.println("\tpi =" + (double) m / n * 4); } }
实例187 求对数值
package Chapter11.math; public class Logarithm { /** * @param 求对数 */ public static void main(String[] args) { double m = 8;// 声明一个double变量。 double value = Math.log(m);// 返回(底数是 e)double 值的自然对数。 double value1 = Math.log10(m);// 返回double值的底数为10的对数。 double value2 = Math.log1p(m);// 返回参数与 1 的和的自然对数。 System.out.println("m的自然对数为:" + value); System.out.println("以10为底m的对数为:" + value1); System.out.println("(m+1)的自然对数为:" + value2); } }
实例188 使用取整函数
package Chapter11.math; import java.util.Scanner; public class Intpart { /** * @param args */ public static void main(String[] args) { double num; Scanner in = new Scanner(System.in);// 由键盘输入一个浮点数 System.out.print("请输入一个浮点数:"); num = in.nextDouble();// 获取这个浮点数 int rint = (int) Math.rint(num);// 调用Math类的rint方法 System.out.println(num + "四舍五入得到整数:" + rint); long round = Math.round(num);// 调用Math类的round方法 System.out.println(num + "四舍五入得到长整数:" + round); int max = (int) Math.floor(num);// 调用Math类的floor方法 System.out.println("小于" + num + "的最大正整数:" + max); int min = (int) Math.ceil(num);// 调用Math类的ceil方法 System.out.println("大于" + num + "的最小正整数:" + min); } }
11.2 Random类的使用
实例189 随机数
package Chapter11.Random; import java.util.Random; public class RandomClass { public static void randomTypes() {// 获取各种数据类型的随机数 System.out.println("1. 使用Random类的构造方法生成随机数的示例如下:"); Random rdm = new Random();// 使用默认的构造方法创建一个Random对象 int a = 0, b = 0, c = 0, d = 0, e = 0;// 定义计算变量 while (true) {// 随机产生5个各种类型的随机数 if (a < 5) { if (a == 0) { System.out.println("生成double型的随机数列如下:"); } System.out.print(rdm.nextDouble() + " "); // 按均匀分布产生[0, // 1)范围的double a++; } else if (a == 5 && b < 5) { if (a == 5 && b == 0) { System.out.println("\n生成float型的随机数列如下:"); } System.out.print(rdm.nextFloat() + " "); // 按均匀分布产生大于等于0,小于1的float b++; } else if (b == 5 && c < 5) { if (b == 5 && c == 0) { System.out.println("\n生成long型的随机数列如下:"); } System.out.print(rdm.nextLong() + " "); // 按均匀分布产生长整数 c++; } else if (c == 5 && d < 5) { if (c == 5 && d == 0) { System.out.println("\n生成int型的随机数列如下:"); } System.out.print(rdm.nextInt() + " "); // 按均匀分布产生整数 d++; } else if (d == 5 && e < 5) { if (d == 5 && e == 0) { System.out.println("\n生成按正态分布产生的double型随机数列如下:"); } System.out.print(rdm.nextGaussian() + " "); // 按正态分布产生随机数 e++; } else if (e == 5) { break; } } } public static void nextInt() { // 获取指定范围内的随机数 System.out.println("\n\n2. 在指定范围内产生随机序列:"); System.out.print("在[0,8)的范围内产生的随机整数序列如下: "); Random rdm = new Random(); for (int i = 0; i < 5; i++) { System.out.print(rdm.nextInt(7) + " "); // Random的nextInt(int,n)方法返回一个[0, // n]范围内的随机数 } System.out.println(); System.out.print("在[5,50)的范围内产生的随机整数序列如下:"); for (int i = 0; i < 5; i++) { System.out.print(5 + rdm.nextInt(45) + " "); } System.out.println(); System.out.print("在[0,100)范围内生成float型的随机整数序列如下: "); for (int i = 0; i < 5; i++) { System.out.print((int) (rdm.nextFloat() * 100) + " "); } System.out.println("\n"); } public static void RandomSeed() { // 使用种子来创建随机数列 // 构造函数的参数是long类型,是生成随机数的种子。 System.out.println("3. 使用种子产生随机数"); Random rad = new Random(12);// 创建第一个Random对象 // 通过种子相同的两个Random对象来验证"种子相同,生成的随机数序列也是相同的"。 System.out.println("使用种子为12的Random对象生成[10,100)内随机整数序列: "); for (int i = 0; i < 5; i++) { System.out.print(10 + rad.nextInt(90) + " "); } System.out.println(); Random rad1 = new Random(12);// 创建另一个Random对象 System.out.println("使用另一个种子为12的Random对象生成[10,100)内随机整数序列: "); for (int i = 0; i < 5; i++) { System.out.print(10 + rad1.nextInt(90) + " "); } System.out.println("\n"); } public static void main(String[] args) {// 调用各方法 randomTypes(); nextInt(); RandomSeed(); } }
实例190 验证码
package Chapter11.Random; import java.util.Random; public class Code { static Random rd = new Random(); public static void main(String[] args) { numCode(); charCode(); chineseCode(); mixCode(); } public static void numCode() {// 由0-9组成的全数字验证码 System.out.print("获取的5位数字验证码:"); for (int i = 0; i < 5; i++) { int n = rd.nextInt(10); System.out.print(n + " "); } System.out.println(); } public static void charCode() {// 英文字母和标点符号组成的字符验证码 System.out.print("\n获取的5位字符验证码:"); for (int i = 0; i < 5; i++) { int n = 65 + rd.nextInt(58); System.out.print((char) n + " "); } System.out.println(); } public static void chineseCode() {// 全部由中文组成的验证码 System.out.print("\n获取的5位汉字验证码:"); for (int i = 0; i < 5; i++) { int n = 20000 + rd.nextInt(10000); System.out.print((char) n + " "); } System.out.println(); } public static void mixCode() {// 字符+数字的混合验证码 System.out.print("\n获取的5位混合验证码:"); for (int i = 0; i < 5; i++) { int n = rd.nextInt(123); if (n < 65) { System.out.print(n % 10 + " "); } else { System.out.print((char) n + " "); } } } }
11.3 Date类和Calendar类
实例191 使用Date类获取系统的当前时间
package Chapter11.date; import java.util.Date; public class GetTimer { /** * @param args */ public static void main(String[] args) { Date date = new Date();// 创建一个Date对象 System.out.println("距1970年1月1日00:00:00时间已经过了" + date.getTime() + "毫秒");// 调用Date类的getTime方法 System.out.println("当前的时间:" + date.toGMTString());// 调用Date类的toGMTString方法,不过此方法已过时 } }
实例192 使用DateFormat类获取系统的当前时间
package Chapter11.date; import java.text.DateFormat; import java.util.Date; public class DateFormatClass { /** * @param args */ public static void main(String[] args) { DateFormatClass.date_Format(); } public static void date_Format() { System.out.println("使用DateFormat类获取系统的当前时间的示例如下所示:"); Date date = new Date(); DateFormat shortDateFormat = DateFormat.getDateTimeInstance( DateFormat.SHORT, DateFormat.SHORT); DateFormat mediumDateFormat = DateFormat.getDateTimeInstance( DateFormat.MEDIUM, DateFormat.MEDIUM); DateFormat longDateFormat = DateFormat.getDateTimeInstance( DateFormat.LONG, DateFormat.LONG); DateFormat fullDateFormat = DateFormat.getDateTimeInstance( DateFormat.FULL, DateFormat.FULL); System.out.println("SHORT 模式的日期为:" + shortDateFormat.format(date)); System.out.println("MEDIUM 模式的日期为:" + mediumDateFormat.format(date)); System.out.println("LONG 模式的日期为:" + longDateFormat.format(date)); System.out.println("FULL 模式的日期为:" + fullDateFormat.format(date)); } }
实例193 使用GregorianCalendar类获取系统的当前时间
package Chapter11.date; import java.text.DateFormat; import java.util.Date; import java.util.GregorianCalendar; public class GregorianCalendarClass { /** * @param args */ public static void main(String[] args) { GregorianCalendarClass calendarClass = new GregorianCalendarClass(); calendarClass.Date_Format(); } public static void Date_Format() { System.out.println("使用GregorianCalendar类获取系统的当前时间的示例如下所示"); DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.FULL); // 创建一个GregorianCalendar日历对象 GregorianCalendar cal = new GregorianCalendar(); // 将日历系统的日期和时间设置给cal cal.setTime(new Date()); System.out.println("GregorianCalendar类的日期: " + dateFormat.format(cal.getTime())); // 将DAY_OF_WEEK的值设为MONDAY cal.set(GregorianCalendar.DAY_OF_WEEK, GregorianCalendar.SUNDAY); System.out.println("在本周内,星期日的日期为: " + dateFormat.format(cal.getTime())); int count = 0; System.out.println("符合条件的日期如下:"); while (count <= 5) { // DAY_OF_MONTH的值设为7 cal.add(GregorianCalendar.DAY_OF_MONTH, 7); // 判断某月的某日的日期是15号且是星期日 if (cal.get(GregorianCalendar.DAY_OF_MONTH) == 15) { count++; System.out.println(dateFormat.format(cal.getTime())); } } } }
实例194 使用SimpleDateFormat类获取系统的当前时间
package Chapter11.date; import java.text.SimpleDateFormat; import java.util.*; public class SimpleDateClass { public static void main(String[] args) { SimpleDateClass.Simple_Format();// 调用Simple_Date方法 } public static void Simple_Format() { System.out.println("SimpleDateFormat类获取系统当前的时间如下:"); // 创建一个日期格式化,日期的形式为EEEE-MMMM-dd-yyyy SimpleDateFormat bartDateFormat = new SimpleDateFormat( "EEEE-MMMM-dd-yyyy"); // 创建一个日期格式化,日期的形式为yyyy.MM.dd G 'at' HH:mm:ss z SimpleDateFormat b = new SimpleDateFormat( "yyyy.MM.dd G 'at' HH:mm:ss z"); // 创建一个日期格式化,日期的形式为EEE, MMM d, ''yy SimpleDateFormat b1 = new SimpleDateFormat("EEE, MMM d, ''yy"); // 创建一个日期格式化,日期的形式为h:mm a SimpleDateFormat b2 = new SimpleDateFormat("h:mm a"); // 创建一个日期格式化,日期的形式为EEE, d MMM yyyy HH:mm:ss Z SimpleDateFormat b3 = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z"); // 创建一个日期格式化,日期的形式为yyMMddHHmmssZ SimpleDateFormat b4 = new SimpleDateFormat("yyMMddHHmmssZ"); Date date = new Date(); System.out.println("第一种表式形式:" + bartDateFormat.format(date)); System.out.println("第二种表式形式:" + b.format(date)); System.out.println("第三种表式形式:" + b1.format(date)); System.out.println("第四种表式形式:" + b2.format(date)); System.out.println("第五种表式形式:" + b3.format(date)); System.out.println("第六种表式形式:" + b4.format(date)); } }
实例195 显示某年某月某一周的信息
package Chapter11.date; import java.util.Calendar; public class ShowWeek { public static void main(String[] args) { Calendar calendar = Calendar.getInstance();// 获取一个Calendar对象 int count = 0;// 定义一个计数变量 calendar.set(Calendar.YEAR, 2010);// 设置年份 calendar.set(Calendar.MONTH, 2);// 设置月份 calendar.set(Calendar.DATE, 8);// 设置日期 System.out.println("2010年3月9号一周内的日历如下:"); System.out.println("星期日\t星期一\t星期二\t星期三\t星期四\t星期五\t星期六"); while (count < 7) { calendar.add(Calendar.DAY_OF_MONTH, 1);// 设置添加日历的周期为1 int day = calendar.getTime().getDay();// 获取日历的星期几表示数,例如:0:表示星期日 if (count == 0) {// 根据星期几来决定输入几个tab for (int i = 0; i < day; i++) { System.out.print("\t"); } } if (day == 0) {// 如果是周日了则换行 System.out.println(); } System.out.print(calendar.getTime().getDate() + "\t");// 获取日历中日期数 count++; } } }
实例196 显示某年某月的信息
package Chapter11.date; import java.util.Calendar; public class ShowMonth { public static void main(String[] args) { Calendar calendar = Calendar.getInstance();// 获取一个Calendar对象 int count = 0;// 定义一个计数变量 int year = 2011; int month = 5; calendar.set(Calendar.YEAR, year);// 设置年份 calendar.set(Calendar.MONTH, month);// 设置月份 calendar.set(Calendar.DATE, 0);// 设置日期 int days = chooseMonth(month + 1); System.out.println(year + " 年 " + (month + 1) + " 月 的 日 历 如 下:"); System.out.println("星期日\t星期一\t星期二\t星期三\t星期四\t星期五\t星期六"); while (count < days) { calendar.add(Calendar.DAY_OF_MONTH, 1);// 设置添加日历的周期为1 int day = calendar.getTime().getDay();// 获取日历的星期几表示数,例如:0:表示星期日 if (count == 0) {// 根据星期几来决定输入几个tab for (int i = 0; i < day; i++) { System.out.print("\t"); } } if (day == 0) {// 如果是周日了则换行 System.out.println(); } System.out.print(calendar.getTime().getDate() + "\t");// 获取日历中日期数 count++; } } public static int chooseMonth(int m) {// 根据月份选择天数 int days = 0; switch (m) { case 2: days = 28; break; case 1: case 3: case 5: case 7: case 8: case 10: case 12: days = 31; break; case 4: case 6: case 9: case 11: days = 30; break; default: days = 0; } return days; } }
实例197 时间的设置与获取
package Chapter11.date; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.*; import javax.swing.*; import javax.swing.border.TitledBorder; public class WriteTime extends JFrame { private JPanel panel; private BorderLayout borderLayout1 = new BorderLayout(); // 创建组件实例 private JLabel jLabel1 = new JLabel(); private JButton jButton1 = new JButton(); private JPanel jPanel1 = new JPanel(); private JTextField jtf1 = new JTextField(); private JTextField jtf2 = new JTextField(); private JTextField jtf3 = new JTextField(); private JTextField jtf4 = new JTextField(); private JTextField jtf5 = new JTextField(); private JTextField jtf6 = new JTextField(); private TitledBorder tb1; private TitledBorder tb2; private TitledBorder tb3; private TitledBorder tb4; private TitledBorder tb5; private TitledBorder tb6; private TitledBorder tb7; private GridLayout gridLayout = new GridLayout(); String year, month, day, hour, minute, second;// 各时间项 Calendar cal = Calendar.getInstance();// 创建Calendar的实例 private void Jinit() { // 初始化时间项的值 this.year = String.valueOf(cal.get(Calendar.YEAR));// this.month = String.valueOf(cal.get(Calendar.MONTH)); this.day = String.valueOf(cal.get(Calendar.DATE)); this.hour = String.valueOf(cal.get(Calendar.HOUR)); this.minute = String.valueOf(cal.get(Calendar.MINUTE)); this.second = String.valueOf(cal.get(Calendar.SECOND)); // 创建TitledBorder边界实例 panel = (JPanel) this.getContentPane(); tb1 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "年份"); tb2 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "月份"); tb3 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "日期"); tb4 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "时"); tb5 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "分"); tb6 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "秒"); tb7 = new TitledBorder(BorderFactory.createEtchedBorder(Color.red, Color.white), "设置时间"); jLabel1.setFont(new Font("Dialog", Font.BOLD, 14)); jLabel1 .setText("Now:" + this.year + "年" + this.month + "月" + this.day + "日" + this.hour + "时" + this.minute + "分" + this.second + "秒");// 显示时间 panel.setLayout(borderLayout1); this.setSize(new Dimension(468, 140)); this.setVisible(true); this.setTitle("时间的设置与获取示例"); jButton1.setText("重新获取时间"); jButton1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { jButton1_actionPerformed(e); } }); // 设置JTextField组件的初始显示数,并添加边界 jtf1.setBorder(this.tb1); jtf1.setText(this.year); jtf2.setBorder(this.tb2); jtf2.setText(this.month); jtf3.setBorder(this.tb3); jtf3.setText(this.day); jtf4.setBorder(this.tb4); jtf4.setText(this.hour); jtf5.setBorder(this.tb5); jtf5.setText(this.minute); jtf6.setBorder(this.tb6); jtf6.setText(this.second); jPanel1.setLayout(gridLayout); jPanel1.setBorder(this.tb7); // 添加各组件 panel.add(jLabel1, BorderLayout.SOUTH); panel.add(jButton1, BorderLayout.CENTER); panel.add(jPanel1, BorderLayout.NORTH); jPanel1.add(jtf1, null); jPanel1.add(jtf2, null); jPanel1.add(jtf3, null); jPanel1.add(jtf4, null); jPanel1.add(jtf5, null); jPanel1.add(jtf6, null); } public void jButton1_actionPerformed(ActionEvent e) { // 设置时间 cal.set(Integer.parseInt(this.jtf1.getText()), Integer .parseInt(this.jtf2.getText()), Integer.parseInt(this.jtf3 .getText()), Integer.parseInt(this.jtf4.getText()), Integer .parseInt(this.jtf5.getText()), Integer.parseInt(this.jtf6 .getText())); // 更新时间项数据 this.year = String.valueOf(cal.get(Calendar.YEAR)); this.month = String.valueOf(cal.get(Calendar.MONTH)); this.day = String.valueOf(cal.get(Calendar.DATE)); this.hour = String.valueOf(cal.get(Calendar.HOUR)); this.minute = String.valueOf(cal.get(Calendar.MINUTE)); this.second = String.valueOf(cal.get(Calendar.SECOND)); // 显示当前时间 jLabel1 .setText("Now:" + this.year + "年" + this.month + "月" + this.day + "日" + this.hour + "时" + this.minute + "分" + this.second + "秒"); } public static void main(String[] args) { new WriteTime().Jinit(); } }
实例198 万年历(农历和阳历的互换)
package com.java; import java.util.Calendar; public class LunarCalendar { public static void main(String[] args) { Solar s = new Solar(); s.getDate(2020, 9); String t = MutualConversion.solarToLundar(2009, 10, 12); String[] str = t.split("-"); Lunar la = new Lunar(Integer.parseInt(str[0]), Integer .parseInt(str[1]), Integer.parseInt(str[2])); System.out.println("\n\n阳历2009-10-12日对应的农历日期为:"+la.toString(1)+" "+la.toWeek()); String t1 = MutualConversion.lundarToSolar(2019, 1, 1); String[] str1 = t1.split("-"); Solar s1 = new Solar(Integer.parseInt(str1[0]), Integer .parseInt(str1[1]), Integer.parseInt(str1[2])); System.out.println("\n农历2019-1-1日对应的阳历日期为:"+s1.toString()+" "+s1.toWeek()); } } // 自定义日历类,其作用是实现阳历和农历日期相互转换的功能 class MutualConversion { // 阵列storeLunarMonth存储在每月一天的资料,每年从1901年到2100年的农历,农历只能是29或30天, // 每月表达12(或13)的二进制位在一年内,这是30 1中的相应位置的形式天,否则,29天 private static final int[]storeLunarMonth = { 0x4ae0,0xa570,0x5268,0xd260,0xd950,0x6aa8, 0x56a0,0x9ad0,0x4ae8,0x4ae0,//1910 0xa4d8,0xa4d0,0xd250,0xd548,0xb550,0x56a0, 0x96d0,0x95b0,0x49b8,0x49b0,//1920 0xa4b0,0xb258,0x6a50,0x6d40,0xada8, 0x2b60,0x9570,0x4978,0x4970,0x64b0, //1930 0xd4a0,0xea50,0x6d48,0x5ad0,0x2b60, 0x9370,0x92e0,0xc968,0xc950,0xd4a0, //1940 0xda50,0xb550,0x56a0,0xaad8,0x25d0, 0x92d0,0xc958,0xa950,0xb4a8,0x6ca0, //1950 0xb550,0x55a8,0x4da0,0xa5b0,0x52b8, 0x52b0,0xa950,0xe950,0x6aa0,0xad50, //1960 0xab50,0x4b60,0xa570,0xa570, 0x5260,0xe930,0xd950,0x5aa8,0x56a0,0x96d0, //1970 0x4ae8,0x4ad0,0xa4d0,0xd268,0xd250, 0xd528,0xb540,0xb6a0,0x96d0,0x95b0, //1980 0x49b0,0xa4b8,0xa4b0,0xb258,0x6a50, 0x6d40,0xada0,0xab60,0x9370,0x4978, // 1990 0x4970,0x64b0,0x6a50,0xea50,0x6b28, 0x5ac0,0xab60,0x9368,0x92e0,0xc960, //2000 0xd4a8,0xd4a0,0xda50,0x5aa8,0x56a0, 0xaad8,0x25d0,0x92d0,0xc958,0xa950, //2010 0xb4a0,0xb550,0xb550,0x55a8,0x4ba0 ,0xa5b0,0x52b8,0x52b0,0xa930,0x74a8, //2020 0x6aa0,0xad50,0x4da8,0x4b60,0x9570, 0xa4e0,0xd260,0xe930,0xd530,0x5aa0, //2030 0x6b50,0x96d0,0x4ae8,0x4ad0,0xa4d0, 0xd258,0xd250,0xd520,0xdaa0,0xb5a0, //2040 0x56d0,0x4ad8,0x49b0,0xa4b8,0xa4b0, 0xaa50,0xb528,0x6d20,0xada0,0x55b0 //2050 }; // 阵列storeLunarLeapMonth存储的是农历1901年至2050年闰月的信息,0表示该年没有闰月,每个字符元素表示的存储两年。 // 例如0x50该字符存储的是2009和2010年,0x表示八进制,5表示2009年闰5月,0表示2010没有闰月 private static final char[] storeLunarLeapMonth = { 0x00, 0x50, 0x04, 0x00, 0x20, // 1910 0x60, 0x05, 0x00, 0x20, 0x70, // 1920 0x05, 0x00, 0x40, 0x02, 0x06, // 1930 0x00, 0x50, 0x03, 0x07, 0x00, // 1940 0x60, 0x04, 0x00, 0x20, 0x70, // 1950 0x05, 0x00, 0x30, 0x80, 0x06, // 1960 0x00, 0x40, 0x03, 0x07, 0x00, // 1970 0x50, 0x04, 0x08, 0x00, 0x60, // 1980 0x04, 0x0a, 0x00, 0x60, 0x05, // 1990 0x00, 0x30, 0x80, 0x05, 0x00, // 2000 0x40, 0x02, 0x07, 0x00, 0x50, // 2010 0x04, 0x09, 0x00, 0x60, 0x04, // 2020 0x00, 0x20, 0x60, 0x05, 0x00, // 2030 0x30, 0xb0, 0x06, 0x00, 0x50, // 2040 0x02, 0x07, 0x00, 0x50, 0x03 // 2050 }; // 用矩阵存领存储从1901~2050年每一年的阳历和农历的偏移天数 private static final char[] offseOfDays = { 49, 38, 28, 46, 34, 24, 43, 32, 21, 40, // 1910 29, 48, 36, 25, 44, 34, 22, 41, 31, 50, // 1920 38, 27, 46, 35, 23, 43, 32, 22, 40, 29, // 1930 47, 36, 25, 44, 34, 23, 41, 30, 49, 38, // 1940 26, 45, 35, 24, 43, 32, 21, 40, 28, 47, // 1950 36, 26, 44, 33, 23, 42, 30, 48, 38, 27, // 1960 45, 35, 24, 43, 32, 20, 39, 29, 47, 36, // 1970 26, 45, 33, 22, 41, 30, 48, 37, 27, 46, // 1980 35, 24, 43, 32, 50, 39, 28, 47, 36, 26, // 1990 45, 34, 22, 40, 30, 49, 37, 27, 46, 35, // 2000 23, 42, 31, 21, 39, 28, 48, 37, 25, 44, // 2010 33, 23, 41, 31, 50, 39, 28, 47, 35, 24, // 2020 42, 30, 21, 40, 28, 47, 36, 25, 43, 33, // 2030 22, 41, 30, 49, 37, 26, 44, 33, 23, 42, // 2040 31, 21, 40, 29, 47, 36, 25, 44, 32, 22, // 2050 }; static boolean isLeapYearOfSolar(int year) {// 判断是否有闰年 return ((year % 4 == 0) && (year % 100 != 0) || year % 400 == 0); } // 获取阳历中每个月的天数 static int getSolarMonthOfDays(int year, int month) { if ((month == 1) || (month == 3) || (month == 5) || (month == 7) || (month == 8) || (month == 10) || (month == 12)) return 31; else if ((month == 4) || (month == 6) || (month == 9) || (month == 11)) return 30; else if (month == 2) { if (isLeapYearOfSolar(year)) return 29; else return 28; } else return 0; } // 获取新年的偏移天 static int L_getOffsetOfDays(int year, int month, int day) { int days = 0; for (int i = 1; i < month; i++) { days += getSolarMonthOfDays(year, i); } days += day - 1; return days; } static int L_getLeapMonth(int year) { char month = storeLunarLeapMonth[(year - 1901) / 2]; if (year % 2 == 0) return (month & 0x0f); else return (month & 0xf0) >> 4; } // 获取当前年月的农历月 static int L_getMonthDays(int year, int month) { int leapMonth = L_getLeapMonth(year); if ((month > 12) && (month - 12 != leapMonth) || (month < 0)) { System.out.println("输入的月份有错误"); return -1; } if (month - 12 == leapMonth) { if ((storeLunarMonth[year - 1901] & (0x8000 >> leapMonth)) == 0) return 29; else return 30; } if ((leapMonth > 0) && (month > leapMonth)) month++; if ((storeLunarMonth[year - 1901] & (0x8000 >> (month - 1))) == 0) return 29; else return 30; } // 获取当前年份的农历年 static int getLunarYear(int year) { int iYearDays = 0; int leapMonth = L_getLeapMonth(year); for (int i = 1; i < 13; i++) iYearDays += L_getMonthDays(year, i); if (leapMonth > 0) iYearDays += L_getMonthDays(year, leapMonth + 12); return iYearDays; } static int getOffsetOfDays(int year, int month, int day) { int days = 0; int leapMonth = L_getLeapMonth(year); if ((leapMonth > 0) && (leapMonth == month - 12)) { month = leapMonth; days += L_getMonthDays(year, month); } for (int i = 1; i < month; i++) { days += L_getMonthDays(year, i); if (i == leapMonth) days += L_getMonthDays(year, leapMonth + 12); } days += day - 1; return days; } // 阳历转换成农历 static String solarToLundar(int year, int month, int day) { int L_day, L_month, L_year; int days = L_getOffsetOfDays(year, month, day); int leapMonth = L_getLeapMonth(year); if (days < offseOfDays[year - 1901]) { L_year = year - 1; days = offseOfDays[year - 1901] - days; L_day = days; for (L_month = 12; days > L_getMonthDays(L_year, L_month); L_month--) { L_day = days; days -= L_getMonthDays(L_year, L_month); } if (0 == L_day) L_day = 1; else L_day = L_getMonthDays(L_year, L_month) - days + 1; } else { L_year = year; days -= offseOfDays[year - 1901]; L_day = days + 1; for (L_month = 1; days >= 0; L_month++) { L_day = days + 1; days -= L_getMonthDays(L_year, L_month); if ((leapMonth == L_month) && (days > 0)) { L_day = days; days -= L_getMonthDays(L_year, L_month + 12); if (days <= 0) { L_month += 12 + 1; break; } } } L_month--; } return "" + L_year + "-" + L_month + "-" + L_day; } // 农历转换成阳历 static String lundarToSolar(int year, int month, int day) { int S_year, S_month, S_day; int days = getOffsetOfDays(year, month, day) + offseOfDays[year - 1901]; int iYearDays = isLeapYearOfSolar(year) ? 366 : 365; if (days >= iYearDays) { S_year = year + 1; days -= iYearDays; } else { S_year = year; } S_day = days + 1; for (S_month = 1; days >= 0; S_month++) { S_day = days + 1; days -= getSolarMonthOfDays(S_year, S_month); } S_month--; return "" + S_year + "-" + S_month + "-" + S_day; } } // 自定义星期类 class CustomWeek { int week; private String weeks[] = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };// 定义一个String数组,存储一周七天的星期 public CustomWeek() {// 默认星期为星期日 week = 0; } // 0:星期日 1:星期一 2:星期二 3:星期三 4:星期四 5:星期五 6:星期六 public CustomWeek(int w) { if ((w > 6) || (w < 0)) { System.out .println("CustomWeek out of range, I think you want Sunday"); this.week = 0; } else this.week = w; } public String toString() { return weeks[week]; } } // 自定义日期类 class CustomDate { public int year; public int month; public int day; private static int checkYear(int year) {// 检察输入的年份是否在指定的年份范围中 if ((year > 1901) && (year < 2050)) return year; else { System.out.println("输入的年份不在1901~2050之间,默认年份为1991年"); return 1991; } } // 构造方法 public CustomDate(int year, int month, int day) { this.year = checkYear(year); this.month = month; this.day = day; } public CustomDate(int year, int month) { this.year = checkYear(year); this.month = month; this.day = 1; } public CustomDate(int year) { this.year = checkYear(year); this.month = 1; this.day = 1; } public CustomDate() {// 默认初始化的日期为1991-01-01 this.year = 1991; this.month = 1; this.day = 1; } public String toString() { return "" + this.year + (this.month > 9 ? "" + this.month : "0" + this.month)// 月以MM的形式表示 + (this.day > 9 ? "" + this.day : "0" + this.day);// 日以dd的形式表示 } public boolean equals(CustomDate md) { return ((md.day == this.day) && (md.month == this.month) && (md.year == this.year)); } } // 阳历日期类,继承自定义日期 class Solar extends CustomDate { private static int checkMonth(int month) {// 检查月份是否越有效范围 if (month > 12) { System.out.println("输入的月份越界, 默认月份为12月 "); return 12; } else if (month < 1) { System.out.println("输入的月份越界, 默认月份为1月"); return 1; } else return month; } private static int checkDay(int year, int month, int day) {// 检查日期是否越有效范围 int iMonthDays = MutualConversion.getSolarMonthOfDays(year, month); if (day > iMonthDays) { System.out.println("输入的日期越界, 默认日期为 " + iMonthDays + " "); return iMonthDays; } else if (day < 1) { System.out.println("输入的日期越界, 默认日期为1号"); return 1; } else return day; } // SolarDate类的构造方法 public Solar(int year, int month, int day) { super(year); this.month = checkMonth(month); this.day = checkDay(this.year, this.month, day); } public Solar(int year, int month) { super(year); this.month = checkMonth(month); } public Solar(int year) { super(year); } public Solar() { super(); } // 以字符串的形式输出 public String toString() { return "" + this.year + (this.month > 9 ? "-" + this.month : "-0" + this.month) + (this.day > 9 ? "-" + this.day : "-0" + this.day); } // 获取输入的年月日是星期几 public CustomWeek toWeek() { int days = 0; for (int i = 1901; i < year; i++) { if (MutualConversion.isLeapYearOfSolar(i)) days += 366; else days += 365; } days += MutualConversion.L_getOffsetOfDays(year, month, day); return new CustomWeek((days + 2) % 7); } public Lunar dateToLunar() {// 将输入日期转换成农历日期 int year, month, day, iDate; Lunar ld; iDate = Integer.parseInt(MutualConversion.solarToLundar(this.year, this.month, this.day)); year = iDate / 10000; month = iDate % 10000 / 100; day = iDate % 100; ld = new Lunar(year, month, day); return ld; } public void getDate(int year, int month) { Calendar calendar = Calendar.getInstance();// 获取一个Calendar对象 int count = 0;// 定义一个计数变量 calendar.set(Calendar.YEAR, year);// 设置年份 calendar.set(Calendar.MONTH, month - 1);// 设置月份 calendar.set(Calendar.DATE, 0);// 设置日期 int days = MutualConversion.getSolarMonthOfDays(year, month); ; System.out.println(year + " 年 " + month + " 月 份 的 万 年 历 如 下:"); System.out.println("星期日\t\t星期一\t\t星期二\t\t星期三\t\t星期四\t\t星期五\t\t星期六"); while (count < days) { calendar.add(Calendar.DAY_OF_MONTH, 1);// 设置添加日历的周期为1 int day = calendar.getTime().getDay();// 获取日历的星期几表示数,例如:0:表示星期日 if (count == 0) {// 根据星期几来决定输入几个tab for (int i = 0; i < day; i++) { System.out.print("\t\t"); } } if (day == 0) {// 如果是周日了则换行 System.out.println(); } String time = MutualConversion.solarToLundar(year, month, calendar .getTime().getDate()); String[] str = time.split("-"); Lunar la = new Lunar(Integer.parseInt(str[0]), Integer .parseInt(str[1]), Integer.parseInt(str[2])); String name = la.toString(0); System.out.print(calendar.getTime().getDate() + " ");// 获取日历中日期数 System.out.print(name + "\t");// 获取日历中日期数 count++; } } } // 农历日期类,继承自定义日期类 class Lunar extends CustomDate { private String upperFigure[] = { "零", "一", "二", "三", "四", "五", "六", "七", "八", "九", "十" }; private static int checkDay(int year, int month, int day) {// 检查日期是否越有效范围 int iMonthDays = MutualConversion.getSolarMonthOfDays(year, month); if (day > iMonthDays) { System.out.println("输入的日期越界, 默认日期为 " + iMonthDays + " "); return iMonthDays; } else if (day < 1) { System.out.println("输入的日期越界, 默认日期为1号"); return 1; } else return day; } private static int checkMonth(int year, int month) {// 检查月份是否越有效范围 if ((month > 12) && (month == MutualConversion.L_getLeapMonth(year) + 12)) { return month; } else if (month > 12) { System.out.println("输入的月份越界, 默认月份为12月 "); return 12; } else if (month < 1) { System.out.println("输入的月份越界, 默认月份为1月"); return 1; } else return month; } // LunarDate类的构造方法 public Lunar(int year, int month, int day) { super(year); this.month = checkMonth(this.year, month); this.day = checkDay(this.year, this.month, day); } public Lunar(int year, int month) { super(year); this.month = checkMonth(this.year, month); } public Lunar(int year) { super(year); } public Lunar() { super(); } // 以字符串的形式输出 public String toString(int n) { String sCalendar = ""; if (n == 1) { sCalendar += "农历" + upperFigure[year / 1000] + upperFigure[year % 1000 / 100] + upperFigure[year % 100 / 10] + upperFigure[year % 10] + "(" + toChineseEra() + ")年"; } if (month > 12) { month -= 12; sCalendar += "闰"; } if (month == 12) sCalendar += "腊月"; else if (month == 11) sCalendar += "冬月"; else if (month == 1) sCalendar += "正月"; else sCalendar += upperFigure[month] + "月"; if (day > 29) sCalendar += "三十"; else if (day > 20) sCalendar += "二十" + upperFigure[day % 20]; else if (day == 20) sCalendar += "二十"; else if (day > 10) sCalendar += "十" + upperFigure[day % 10]; else sCalendar += "初" + upperFigure[day]; return sCalendar; } public CnWeek toWeek() {// 获取输入日期的星期几 int days = 0; for (int i = 1901; i < year; i++) days += MutualConversion.getLunarYear(i); days += MutualConversion.getOffsetOfDays(year, month, day); return new CnWeek((days + 2) % 7); } public ChineseEra toChineseEra() { return new ChineseEra(year); } public Solar toSolarDate() {// 转换成阳历 int year, month, day, iDate; Solar sd; iDate = Integer.parseInt(MutualConversion.lundarToSolar(this.year, this.month, this.day)); year = iDate / 10000; month = iDate % 10000 / 100; day = iDate % 100; sd = new Solar(year, month, day); return sd; } } class CnWeek extends CustomWeek {// Week的子类 private String sCnWeek[] = { "日", "一", "二", "三", "四", "五", "六" }; // 调用父类的构造方法 public CnWeek() { super(); } public CnWeek(int week) { super(week); } public String toString() { return "星期" + sCnWeek[this.week]; } } // 用天干地支形式表示农历年 class ChineseEra { int year; String[] westernNotation = { "甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸" }; String[] chineseEraNotation = { "子", "丑", "寅", "卯", "辰", "巳", "午", "未", "申", "酉", "戌", "亥" }; public ChineseEra() { int year = 1991; } public ChineseEra(int year) { if ((year < 2050) && (year > 1901)) this.year = year; else this.year = 1991; } public String toString() { int temp; temp = Math.abs(year - 1924); return westernNotation[temp % 10] + chineseEraNotation[temp % 12]; } }
11.4 Formatter类的使用
实例199 时间格式转换符的使用
package Chapter11.format; import java.util.Formatter; public class FormatterUsage { /** * @param args */ public static void main(String[] args) { Object[] ob = new Object[2];// 创建Object数组 // 给数组赋值 ob[0] = Integer.valueOf(51); ob[1] = Integer.valueOf(1293); Formatter fmt = null; System.out.println("第一种输出方式:"); fmt = new Formatter(); // 以默认的存储区为目标,创建对象 Object[] ob1 = new Object[2]; ob1[0] = Double.valueOf(1112.12675456); ob1[1] = Double.valueOf(0.1258989); fmt.format("输出到自带存储区,每个输出项占8个字符位:%4.3f %5.2f\n", ob1); // 格式化输出数据,输出到自己的存储区 System.out.print(fmt); // 再从对象的存储区中输出到屏幕 System.out.println("\n第二种输出方式:"); fmt = new Formatter(System.out); // 以标准输出设备为目标,创建对象 fmt.format("直接输出,每个输出项占5个字符位:%5d%5d\n\n", ob); // 格式化输出数据,并输出到标准输出设备 System.out.println("第三种输出方式:"); StringBuffer buf = new StringBuffer(); fmt = new Formatter(buf); // 以指定的字符串为目标,创建对象 fmt.format("输出到指定的缓冲区,每个输出项占8个字符位:%8d%8d\n\n", ob); // 格式化输出数据,输出到buf中 System.out.print(buf); // 再从buf中输出到屏幕 } }
实例200 数据格式转换符的使用
package Chapter11.format; import java.util.Formatter; public class FormatterUsage { /** * @param args */ public static void main(String[] args) { Object[] ob = new Object[2];// 创建Object数组 // 给数组赋值 ob[0] = Integer.valueOf(51); ob[1] = Integer.valueOf(1293); Formatter fmt = null; System.out.println("第一种输出方式:"); fmt = new Formatter(); // 以默认的存储区为目标,创建对象 Object[] ob1 = new Object[2]; ob1[0] = Double.valueOf(1112.12675456); ob1[1] = Double.valueOf(0.1258989); fmt.format("输出到自带存储区,每个输出项占8个字符位:%4.3f %5.2f\n", ob1); // 格式化输出数据,输出到自己的存储区 System.out.print(fmt); // 再从对象的存储区中输出到屏幕 System.out.println("\n第二种输出方式:"); fmt = new Formatter(System.out); // 以标准输出设备为目标,创建对象 fmt.format("直接输出,每个输出项占5个字符位:%5d%5d\n\n", ob); // 格式化输出数据,并输出到标准输出设备 System.out.println("第三种输出方式:"); StringBuffer buf = new StringBuffer(); fmt = new Formatter(buf); // 以指定的字符串为目标,创建对象 fmt.format("输出到指定的缓冲区,每个输出项占8个字符位:%8d%8d\n\n", ob); // 格式化输出数据,输出到buf中 System.out.print(buf); // 再从buf中输出到屏幕 } }
11.5 System类的使用
实例201 记录程序执行的时间
package Chapter11.system; public class RecordTimes { /** * @param args */ public static void main(String args[]) { try { long start = System.currentTimeMillis();// 记录程序开始执行时的时间 System.out.println("开始执行的时间为:" + start); Thread.sleep(3000); long end = System.currentTimeMillis();// 记录程序结束执行时的时间 System.out.println("结束执行的时间为: " + end); System.out.println("共执行了:" + (end - start) + "毫秒");// 结束时间-开始时间=执行了的时间 } catch (InterruptedException el) { el.printStackTrace(); } } }
实例202 程序的退出
package Chapter11.system; public class Exit extends Thread { /** * @param args */ public static void main(String args[]) { Exit exit = new Exit(); Thread th = Thread.currentThread();// 获取主线程 exit.start(); System.out.println("主线程开始运行。。。"); try { System.out.println("休眠开始~~"); th.sleep(1000);// 令线程暂停运行 } catch (InterruptedException el) { el.printStackTrace(); } System.out.println("主线程运行结束"); } public void run() { // 线程类的抽象方法 System.out.println("线程正在运行中,调用System.exit(0)方法,强制JVM退出!!"); System.exit(0);// 强制JVM退出 } }
实例203 获取程序运行环境的信息
package Chapter11.system; public class INFO { /** * @param args */ public static void main(String[] args) { // 通过调用System类的getProperty方法来获取相应的属性值 System.out.println("用户的账户名称:" + System.getProperty("user.name")); System.out.println("当前用户工作目录:" + System.getProperty("user.dir")); System.out.println("用户的home路径:" + System.getProperty("user.home")); System.out.println("类所在的路径:" + System.getProperty("java.class.path")); System.out.println("操作系统的名称:" + System.getProperty("os.name")); System.out.println("操作系统的版本:" + System.getProperty("os.version")); System.out.println("操作系统的架构:" + System.getProperty("os.arch")); System.out.println("虚拟机实现的版本:" + System.getProperty("java.vm.version")); System.out.println("虚拟机实现的生产商:" + System.getProperty("java.vm.vendor")); System.out.println("默认的临时文件路径:" + System.getProperty("java.io.tmpdir")); System.out.println("运行环境规范的名称:" + System.getProperty("java.specification.name")); System.out.println("Java类格式化的版本号:" + System.getProperty("java.class.version")); System.out.println("Java运行环境的版本:" + System.getProperty("java.version")); System.out.println("Java运行环境的生产商:" + System.getProperty("java.vendor")); System.out.println("Java的安装路径:" + System.getProperty("java.home")); } }