Java获取N天前的日期和N天后的日期

直接上代码：

/** 
    * 获取过去第past天的日期 
    * 
    * @param past 
    * @return 
    */  
   public static String getPastDate(int past) {  
       Calendar calendar = Calendar.getInstance();  
       calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) - past);  
       Date today = calendar.getTime();  
       SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");  
       String result = format.format(today);   
       return result;  
   }  
  
   /** 
    * 获取未来 第 past天的日期 
    * @param past 
    * @return 
    */  
   public static String getFetureDate(int past) {  
       Calendar calendar = Calendar.getInstance();  
       calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) + past);  
       Date today = calendar.getTime();  
       SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");  
       String result = format.format(today);  
       return result;  
   }  ```