android中实现求昨天的日期的代码工具类

前段时间在做项目的时候,突然要用到昨天的日期进行查询数据.在网上也没有找到类似的东西,就自己写了一个

package com.yunduan.util;

public class Yesterday {

 public  String getYesterday(String date){

  String[] strs=date.split("-");

  String yesterday="";

  int year=Integer.parseInt(strs[0]);

  int mounth=Integer.parseInt(strs[1]);

  int day=Integer.parseInt(strs[2]);

  String newDay="";

  if(day-1<10){

   newDay="0"+(day-1);

  }else{

   newDay=day-1+"";

  }

  String newMounth="";

  if(mounth-1<10){

   newMounth="0"+(mounth-1);

  }else{

   newMounth=mounth-1+"";

  }

  String newYear=year-1+"";

  if(Integer.parseInt(newDay)>=1){

   if(mounth<10){

    newMounth="0"+mounth;

    yesterday=year+"-"+newMounth+"-"+newDay;

   }else{

    yesterday=year+"-"+mounth+"-"+newDay;

   }

  }else{

   if(Integer.parseInt(newMounth)>=1){

    if(newMounth.equals("2")){

     if(year%400==0||(year%4==0&&year%100!=0)){

      newDay=29+"";

     }else{

      newDay=28+"";

     }

    }else if(newMounth.equals("1")||newMounth.equals("3")||newMounth.equals("5")||newMounth.equals("7")||newMounth.equals("8")||newMounth.equals("10")||newMounth.equals("12")){

     newDay=31+"";

    }else{

     newDay=30+"";

    }

    yesterday=year+"-"+newMounth+"-"+newDay;

   }else{

    yesterday=newYear+"-12-31";

   }

  }

  return yesterday;

 }

}