java获取昨天日期字符串的方法

import java.text.SimpleDateFormat;
import java.util.Date;
public class Test
{
  /**
   * 获取昨天的日期字符串
   *
   * @param nowDate
   *      当前日期的字符串
   * @return
   */
  public static String getLastDayInfo(String nowDate)
  {
    String yesterday = "";
    int year = 0;
    int month = 0;
    int day = 0;
    try
    {
      year = Integer.parseInt(nowDate.substring(0, nowDate.indexOf("-")));
      month = Integer.parseInt(nowDate.substring(
          nowDate.indexOf("-") + 1, nowDate.lastIndexOf("-")));
      day = Integer.parseInt(nowDate
          .substring(nowDate.lastIndexOf("-") + 1));
      // System.out.println("nowYear = " + year);
      // System.out.println("nowMonth = " + month);
      // System.out.println("dayDay = " + day);
      day = day - 1;
      if (day == 0)
      {
        month = month - 1;
        if (month == 0)
        {
          // January
          month = 12;
          day = 31;
          year = year - 1;
        }
        else
        {
          // not Jan.
          switch (month)
          {
          // 1|3|5|7|8|10|12) day=31;;
          case 1:
            day = 31;
            break;
          case 3:
            day = 31;
            break;
          case 5:
            day = 31;
            break;
          case 7:
            day = 31;
            break;
          case 8:
            day = 31;
            break;
          case 10:
            day = 31;
            break;
          case 12:
            day = 31;
            break;
          // 4|6|9|11) day=30;;
          case 4:
            day = 30;
            break;
          case 6:
            day = 30;
            break;
          case 9:
            day = 30;
            break;
          case 11:
            day = 30;
            break;
          case 2:
            if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
            {
              // leap year
              day = 29;
            }
            else
              day = 28;
          }
        }
      }
      String monthStr = "";
      String dayStr = "";
      if (month < 10)
      {
        monthStr = "0" + String.valueOf(month);
      }
      else
      {
        monthStr = String.valueOf(month);
      }
      if (day < 10)
      {
        dayStr = "0" + String.valueOf(day);
      }
      else
      {
        dayStr = String.valueOf(day);
      }
      yesterday = String.valueOf(year) + "-" + monthStr + "-" + dayStr;
    } catch (Exception e)
    {
      e.printStackTrace();
    }
    return yesterday;
  }
  public static void main(String[] args) throws Exception
  {
    System.out.println(getLastDayInfo("2008-03-01"));
    System.out.println(getLastDayInfo("2008-01-01"));
    SimpleDateFormat sdf = new SimpleDateFormat("MMMM-dd-yyyy");
    Date date;
    String datetime = "02-14-1984";
    try
    {
      date = sdf.parse(datetime);
      System.out.println(sdf.format(date));
    } catch (Exception e)
    {
      System.out.println(e.getMessage());
    }
    Date d = java.sql.Date.valueOf("2008-07-06");
    System.out.println(d.toString());
  }
}