时间日期类

 1 public static void main(String[] args) {
 2         //无参构造方法, 用来创建当前日期时间的Date对象 
 3         Date d = new Date();
 4         System.out.println(d);
 5         
 6         //long型参数作为构造方法, 用来创建指定时间的日期对象, 参数表示毫秒数
 7         Date d1 = new Date(1495119792068L);
 8         System.out.println(d1);
 9         
10         //long getTime() 返回Date对象表示的毫秒数
11         Date d2 = new Date();
12         long time = d2.getTime();
13         System.out.println(time);
14         
15         //void setTime(Date date) 设置指定Date时间
16         Date d3 = new Date();
17         d3.setTime(1495119792068L);
18         System.out.println(d3);
19     }

 1 public static void main(String[] args) {
 2         Calendar c = Calendar.getInstance();
 3 
 4         // int get(int field) 返回给定日历字段的值
 5         int year = c.get(Calendar.YEAR); 
 6         int month = c.get(Calendar.MONTH) + 1; 
 7         int day = c.get(Calendar.DATE); 
 8 
 9         int hour = c.get(Calendar.HOUR); 
10         int minute = c.get(Calendar.MINUTE);
11         int second = c.get(Calendar.SECOND);
12 
13         System.out.println(year + "年" + month + "月" + day + "日" + hour + "时"
14                 + minute + "分" + second + "秒");
15     }

 1 public static void main(String[] args) {
 2         Calendar c = Calendar.getInstance();
 3         
 4         //void set(int year, int month, int day) 设置Calendar对象的年月日三个字段
 5         c.set(2008,7,8);
 6         int year = c.get(Calendar.YEAR);
 7         int month = c.get(Calendar.MONTH)+1;
 8         int day = c.get(Calendar.DATE);
 9         
10         System.out.println(year+"年"+month+"月"+day+"日");
11 }

 1 public static void main(String[] args) {
 2         Calendar c = Calendar.getInstance();
 3         
 4         //void set(int field, int value) 为指定日历字段设定值
 5         c.set(c.YEAR, 2008);
 6         c.set(c.MONTH, 7);
 7         c.set(c.DATE, 8);
 8         int year = c.get(Calendar.YEAR);
 9         int month = c.get(Calendar.MONTH)+1;
10         int day = c.get(Calendar.DATE);
11         
12         System.out.println(year+"年"+month+"月"+day+"日");
13 }

 1 public static void main(String[] args) {
 2         Calendar c = Calendar.getInstance();
 3         c.set(2008,7,8);
 4         
 5         //void add(int field, int amount) 根据日历规则, 为指定日期字段添加/减去指定值
 6         c.add(Calendar.MONTH, 2);
 7         
 8         int year = c.get(Calendar.YEAR);
 9         int month = c.get(Calendar.MONTH)+1;
10         int day = c.get(Calendar.DATE);
11         
12         System.out.println(year+"年"+month+"月"+day+"日");
13 }

 1 public static void main(String[] args) {
 2         Date d = new Date();
 3         
 4         // Full格式的日期格式器对象
 5         DateFormat fullFormat = DateFormat.getDateInstance(DateFormat.FULL);
 6         // Long格式的日期格式器对象
 7         DateFormat longFormat = DateFormat.getDateInstance(DateFormat.LONG);
 8         // medium格式的日期/时间 格式器对象
 9         DateFormat mediumFormat = DateFormat.getDateInstance(DateFormat.MEDIUM);
10         // short格式的日期/时间 格式器对象
11         DateFormat shortFormat = DateFormat.getDateInstance(DateFormat.SHORT);
12         
13         // 打印格式化的日期或者日期/时间
14         System.out.println("当前日期的完整格式为: "+fullFormat.format(d));
15         System.out.println("当前日期的长格式为: "+longFormat.format(d));
16         System.out.println("当前日期的普通格式为: "+mediumFormat.format(d));
17         System.out.println("当前日期的短格式为: "+shortFormat.format(d));
18 }

1 public static void main(String[] args) throws ParseException {
2         DateFormat df = DateFormat.getDateInstance(DateFormat.LONG);
3         String d = "2017年10月19日";
4         System.out.println(df.parse(d));
5 }

 1 public static void main(String[] args) throws ParseException {
 2         // 构造方法传入一个格式化字符串参数
 3         SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
 4         
 5         // String format(Date date) 将一个Date格式化为指定格式的日期
 6         String date = sdf.format(new Date());
 7         System.out.println(date);
 8         
 9         // Date parse(String source) 将给定字符串解析成Date
10         Date d = sdf.parse("2017/10/19 09:32:52");
11         System.out.println(d);
12 }