获取前一天的日期的方法

public static String getSpecifiedDayBefore(String specifiedDay){ 
//SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd"); 
Calendar c = Calendar.getInstance(); 
Date date=null; 
try { 
date = new SimpleDateFormat("yyyy-MM-dd").parse(specifiedDay); 
} catch (ParseException e) { 
e.printStackTrace(); 
} 
c.setTime(date); 
int day=c.get(Calendar.DATE); 
c.set(Calendar.DATE,day-1); 


String dayBefore=new SimpleDateFormat("yyyyMMdd").format(c.getTime()); 
return dayBefore; 
}