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());  }}