Java 获取当前时间

import javax.swing.JOptionPane;public class TEST {  public static void main(String[] args) {    long totalMilliseconds = System.currentTimeMillis();    long totalSeconds = (totalMilliseconds / 1000);    int currentSecond = (int)(totalSeconds % 60);    long totalMinutes = totalSeconds / 60;    int currentMinute = (int)(totalMinutes % 60);    long totalHours = totalMinutes / 60 + 8;       //简单粗暴    int currentHour = (int)(totalHours % 24);    int totalDays = (int)(totalHours / 24);    if (currentHour > 0) totalDays++;    int currentYear = 2000;    do {      currentYear++;    } while (getTotalDaysInYears(currentYear) < totalDays);    int totalNumOfDaysInTheYear = totalDays -getTotalDaysInYears(currentYear - 1);    int currentMonth = 0;    do {      currentMonth++;    } while (getTotalDaysInMonths(currentYear, currentMonth)      < totalNumOfDaysInTheYear);    int currentDay = totalNumOfDaysInTheYear -      getTotalDaysInMonths(currentYear, currentMonth - 1);    String output = "Current date and time is " +      currentMonth + "/" + currentDay + "/" + currentYear + " " +      currentHour + ":" +      + currentMinute + ":" + currentSecond + " GMT";    JOptionPane.showMessageDialog(null, output);  }  /** Get the total number of days from Jan 1, 1970 to the specified year*/  static int getTotalDaysInYears(int year) {    int total = 0;    // Get the total days from 1970 to the specified year    for (int i = 1970; i <= year; i++)    if (isLeapYear(i))      total = total + 366;    else      total = total + 365;    return total;  }  /** Get the total number of days from Jan 1 to the month in the year*/  static int getTotalDaysInMonths(int year, int month) {    int total = 0;    // Add days from Jan to the month    for (int i = 1; i <= month; i++)      total = total + getNumOfDaysInMonth(year, i);    return total;  }  /** Get the number of days in a month */  static int getNumOfDaysInMonth(int year, int month) {    if (month == 1 || month==3 || month == 5 || month == 7 ||      month == 8 || month == 10 || month == 12)      return 31;    if (month == 4 || month == 6 || month == 9 || month == 11)      return 30;    if (month == 2)      if (isLeapYear(year))        return 29;      else        return 28;    return 0; // If month is incorrect.  }  /** Determine if it is a leap year */  static boolean isLeapYear(int year) {    if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0)))      return true;    return false;  }}

• 代码很长但原理简单，就是运行出来时间慢了8个小时，搜索了下，有修改注册表的，有加时区的，有修改myeclipse的。。。。在这简单粗暴的直接加上8小时~
• 根据不重复造轮子“理论”，找到了如下方法：

import java.util.Date;public class TEST3 {      public static void main(String[] args) {          System.out.println("java.runtime.version:\t"+System.getProperty("java.runtime.version"));          System.out.println("当前时间:\t\t"+new Date());      }  }

• 上述方法在JDK 1.7下能正常运行