日期推迟一周／一年／一月的实例

推迟一周示例：
Calendar curr = Calendar.getInstance();
curr.set(Calendar.DAY_OF_MONTH,curr.get(Calendar.DAY_OF_MONTH)+7);
Date date=curr.getTime();

推迟一个月示例：
Calendar curr = Calendar.getInstance();
curr.set(Calendar.MONTH,curr.get(Calendar.MONTH)+1);
Date date=curr.getTime();

推迟一年示例：
Calendar curr = Calendar.getInstance();
curr.set(Calendar.YEAR,curr.get(Calendar.YEAR)+1);
Date date=curr.getTime();