{"id":2212,"date":"2025-03-02T10:30:37","date_gmt":"2025-03-02T02:30:37","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2212"},"modified":"2025-03-02T10:30:37","modified_gmt":"2025-03-02T02:30:37","slug":"java-%e6%97%a5%e6%9c%9f%e6%97%b6%e9%97%b4","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/02\/java-%e6%97%a5%e6%9c%9f%e6%97%b6%e9%97%b4\/","title":{"rendered":"Java \u65e5\u671f\u65f6\u95f4"},"content":{"rendered":"\n

Java \u63d0\u4f9b\u4e86\u591a\u79cd\u5904\u7406\u65e5\u671f\u548c\u65f6\u95f4\u7684\u65b9\u5f0f\uff0c\u6700\u5e38\u7528\u7684\u65b9\u5f0f\u662f\u5728 java.util<\/code> \u5305\u4e2d\u7684 Date<\/code> \u7c7b\u3001Calendar<\/code> \u7c7b\uff0c\u4ee5\u53ca\u5728 Java 8 \u5f15\u5165\u7684\u65b0\u7684\u65e5\u671f\u548c\u65f6\u95f4 API (java.time<\/code> \u5305)\uff0c\u5b83\u4eec\u66f4\u4e3a\u73b0\u4ee3\u4e14\u529f\u80fd\u66f4\u52a0\u5f3a\u5927\u3002<\/p>\n\n\n\n

1. java.util.Date<\/code> \u7c7b<\/strong><\/h3>\n\n\n\n

Date<\/code> \u7c7b\u662f Java \u6700\u65e9\u7684\u65e5\u671f\u65f6\u95f4\u5904\u7406\u7c7b\u3002\u5b83\u8868\u793a\u4e00\u4e2a\u7279\u5b9a\u7684\u77ac\u95f4\uff0c\u7cbe\u786e\u5230\u6beb\u79d2\u3002<\/p>\n\n\n\n

1.1 \u521b\u5efa Date<\/code> \u5bf9\u8c61<\/h4>\n\n\n\n
\/\/ \u521b\u5efa\u5f53\u524d\u65e5\u671f\u65f6\u95f4\u5bf9\u8c61\nDate date1 = new Date();\nSystem.out.println(date1);  \/\/ \u8f93\u51fa\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\n\n\/\/ \u521b\u5efa\u6307\u5b9a\u65f6\u95f4\u7684 Date \u5bf9\u8c61\nlong timestamp = 1652345678900L;  \/\/ \u6beb\u79d2\u8868\u793a\u7684\u65f6\u95f4\u6233\nDate date2 = new Date(timestamp);\nSystem.out.println(date2);  \/\/ \u8f93\u51fa\u6307\u5b9a\u65f6\u95f4<\/code><\/pre>\n\n\n\n
1.2 \u83b7\u53d6\u65f6\u95f4\u6233<\/h4>\n\n\n\n
Date<\/code> \u7c7b\u53ef\u4ee5\u901a\u8fc7 getTime()<\/code> \u65b9\u6cd5\u83b7\u53d6\u81ea 1970-01-01 00:00:00 UTC<\/code> \u4ee5\u6765\u7684\u6beb\u79d2\u6570\uff08Unix \u65f6\u95f4\u6233\uff09\u3002<\/p>\n\n\n\n
Date date = new Date();\nlong timestamp = date.getTime();\nSystem.out.println(\"\u5f53\u524d\u65f6\u95f4\u6233: \" + timestamp);<\/code><\/pre>\n\n\n\n
1.3 Date<\/code> \u7c7b\u5e38\u7528\u65b9\u6cd5<\/h4>\n\n\n\n
    \n
  • getTime()<\/code>: \u83b7\u53d6\u5f53\u524d\u65e5\u671f\u7684\u65f6\u95f4\u6233\u3002<\/li>\n\n\n\n
  • before()<\/code>: \u5224\u65ad\u5f53\u524d\u65e5\u671f\u662f\u5426\u65e9\u4e8e\u6307\u5b9a\u65e5\u671f\u3002<\/li>\n\n\n\n
  • after()<\/code>: \u5224\u65ad\u5f53\u524d\u65e5\u671f\u662f\u5426\u665a\u4e8e\u6307\u5b9a\u65e5\u671f\u3002<\/li>\n\n\n\n
  • equals()<\/code>: \u6bd4\u8f83\u4e24\u4e2a\u65e5\u671f\u662f\u5426\u76f8\u7b49\u3002<\/li>\n<\/ul>\n\n\n\n
    Date date1 = new Date();\nThread.sleep(1000);  \/\/ \u6682\u505c 1 \u79d2\nDate date2 = new Date();\n\nSystem.out.println(date1.before(date2));  \/\/ \u8f93\u51fa true\uff0c\u56e0\u4e3a date1 \u5728 date2 \u4e4b\u524d<\/code><\/pre>\n\n\n\n
    2. java.util.Calendar<\/code> \u7c7b<\/strong><\/h3>\n\n\n\n
    Calendar<\/code> \u7c7b\u63d0\u4f9b\u4e86\u66f4\u591a\u7684\u65e5\u671f\u64cd\u4f5c\u65b9\u6cd5\uff0c\u5141\u8bb8\u66f4\u7ec6\u7c92\u5ea6\u7684\u64cd\u4f5c\uff0c\u5982\u83b7\u53d6\u5e74\u4efd\u3001\u6708\u4efd\u3001\u5929\u6570\u7b49\u3002<\/p>\n\n\n\n
    2.1 \u521b\u5efa Calendar<\/code> \u5bf9\u8c61<\/h4>\n\n\n\n
    Calendar calendar = Calendar.getInstance();  \/\/ \u83b7\u53d6\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\nSystem.out.println(calendar.getTime());  \/\/ \u8f93\u51fa\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4<\/code><\/pre>\n\n\n\n
    2.2 \u83b7\u53d6\u5e74\u4efd\u3001\u6708\u4efd\u7b49<\/h4>\n\n\n\n
    int year = calendar.get(Calendar.YEAR);\nint month = calendar.get(Calendar.MONTH);  \/\/ \u6708\u4efd\u4ece 0 \u5f00\u59cb\uff0c0 \u8868\u793a 1 \u6708\nint day = calendar.get(Calendar.DAY_OF_MONTH);\nint hour = calendar.get(Calendar.HOUR_OF_DAY);  \/\/ \u83b7\u53d6 24 \u5c0f\u65f6\u5236\u7684\u5c0f\u65f6\nint minute = calendar.get(Calendar.MINUTE);\nint second = calendar.get(Calendar.SECOND);\n\nSystem.out.println(\"\u5f53\u524d\u5e74\u4efd: \" + year);\nSystem.out.println(\"\u5f53\u524d\u6708\u4efd: \" + (month + 1));  \/\/ \u7531\u4e8e\u6708\u4efd\u4ece 0 \u5f00\u59cb\uff0c\u8f93\u51fa\u65f6\u52a0 1<\/code><\/pre>\n\n\n\n
    2.3 \u4fee\u6539\u65e5\u671f\u65f6\u95f4<\/h4>\n\n\n\n
    calendar.add(Calendar.DATE, 5);  \/\/ \u5f53\u524d\u65e5\u671f\u52a0 5 \u5929\nSystem.out.println(\"5 \u5929\u540e: \" + calendar.getTime());\n\ncalendar.add(Calendar.MONTH, -1);  \/\/ \u5f53\u524d\u65e5\u671f\u51cf\u53bb 1 \u4e2a\u6708\nSystem.out.println(\"1 \u4e2a\u6708\u524d: \" + calendar.getTime());<\/code><\/pre>\n\n\n\n
    3. java.time<\/code> \u5305\uff08Java 8+\uff09<\/strong><\/h3>\n\n\n\n
    Java 8 \u5f15\u5165\u4e86\u65b0\u7684\u65e5\u671f\u65f6\u95f4 API\uff0cjava.time<\/code> \u5305\u4e3a\u65e5\u671f\u65f6\u95f4\u7684\u5904\u7406\u63d0\u4f9b\u4e86\u66f4\u5f3a\u5927\u7684\u529f\u80fd\uff0c\u5e76\u4e14\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002\u5b83\u7531\u591a\u4e2a\u7c7b\u7ec4\u6210\uff0c\u4e3b\u8981\u7684\u7c7b\u6709\uff1a<\/p>\n\n\n\n
      \n
    • LocalDate<\/code>: \u53ea\u8868\u793a\u65e5\u671f\uff08\u5e74\u3001\u6708\u3001\u65e5\uff09<\/li>\n\n\n\n
    • LocalTime<\/code>: \u53ea\u8868\u793a\u65f6\u95f4\uff08\u65f6\u3001\u5206\u3001\u79d2\u3001\u7eb3\u79d2\uff09<\/li>\n\n\n\n
    • LocalDateTime<\/code>: \u540c\u65f6\u8868\u793a\u65e5\u671f\u548c\u65f6\u95f4\uff08\u5e74\u3001\u6708\u3001\u65e5\u3001\u65f6\u3001\u5206\u3001\u79d2\u3001\u7eb3\u79d2\uff09<\/li>\n\n\n\n
    • ZonedDateTime<\/code>: \u8868\u793a\u5e26\u65f6\u533a\u7684\u65e5\u671f\u65f6\u95f4<\/li>\n\n\n\n
    • Instant<\/code>: \u8868\u793a\u65f6\u95f4\u6233\uff08\u4ece\u7eaa\u5143\u5f00\u59cb\u7684\u79d2\u6570\uff09<\/li>\n<\/ul>\n\n\n\n
      3.1 \u521b\u5efa LocalDate<\/code> \u548c LocalTime<\/code><\/h4>\n\n\n\n
      \/\/ \u521b\u5efa\u5f53\u524d\u65e5\u671f\nLocalDate today = LocalDate.now();\nSystem.out.println(\"\u4eca\u5929\u7684\u65e5\u671f: \" + today);\n\n\/\/ \u521b\u5efa\u5f53\u524d\u65f6\u95f4\nLocalTime now = LocalTime.now();\nSystem.out.println(\"\u5f53\u524d\u65f6\u95f4: \" + now);<\/code><\/pre>\n\n\n\n
      3.2 \u521b\u5efa LocalDateTime<\/code>\uff08\u65e5\u671f\u548c\u65f6\u95f4\uff09<\/h4>\n\n\n\n
      \/\/ \u521b\u5efa\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\nLocalDateTime nowDateTime = LocalDateTime.now();\nSystem.out.println(\"\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4: \" + nowDateTime);\n\n\/\/ \u521b\u5efa\u6307\u5b9a\u65e5\u671f\u548c\u65f6\u95f4\nLocalDateTime specificDateTime = LocalDateTime.of(2023, 3, 1, 14, 30);\nSystem.out.println(\"\u6307\u5b9a\u65e5\u671f\u548c\u65f6\u95f4: \" + specificDateTime);<\/code><\/pre>\n\n\n\n
      3.3 LocalDateTime<\/code> \u7684\u5e38\u7528\u64cd\u4f5c<\/h4>\n\n\n\n
      LocalDateTime nowDateTime = LocalDateTime.now();\n\n\/\/ \u589e\u52a0 2 \u5929\nLocalDateTime futureDate = nowDateTime.plusDays(2);\nSystem.out.println(\"2 \u5929\u540e: \" + futureDate);\n\n\/\/ \u51cf\u53bb 1 \u4e2a\u6708\nLocalDateTime pastDate = nowDateTime.minusMonths(1);\nSystem.out.println(\"1 \u4e2a\u6708\u524d: \" + pastDate);\n\n\/\/ \u83b7\u53d6\u5e74\u4efd\u3001\u6708\u4efd\u3001\u65e5\u671f\u3001\u5c0f\u65f6\u3001\u5206\u949f\nint year = nowDateTime.getYear();\nint month = nowDateTime.getMonthValue();\nint day = nowDateTime.getDayOfMonth();\nint hour = nowDateTime.getHour();\nint minute = nowDateTime.getMinute();\n\nSystem.out.println(\"\u5e74\u4efd: \" + year);\nSystem.out.println(\"\u6708\u4efd: \" + month);\nSystem.out.println(\"\u65e5\u671f: \" + day);\nSystem.out.println(\"\u5c0f\u65f6: \" + hour);\nSystem.out.println(\"\u5206\u949f: \" + minute);<\/code><\/pre>\n\n\n\n
      3.4 ZonedDateTime<\/code> \u548c\u65f6\u533a<\/h4>\n\n\n\n
      ZonedDateTime<\/code> \u7528\u4e8e\u8868\u793a\u5e26\u65f6\u533a\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002<\/p>\n\n\n\n
      \/\/ \u83b7\u53d6\u5f53\u524d\u5e26\u65f6\u533a\u7684\u65e5\u671f\u548c\u65f6\u95f4\nZonedDateTime zonedDateTime = ZonedDateTime.now();\nSystem.out.println(\"\u5f53\u524d\u5e26\u65f6\u533a\u7684\u65e5\u671f\u548c\u65f6\u95f4: \" + zonedDateTime);\n\n\/\/ \u83b7\u53d6\u6307\u5b9a\u65f6\u533a\u7684\u65e5\u671f\u548c\u65f6\u95f4\nZoneId zoneId = ZoneId.of(\"Asia\/Shanghai\");\nZonedDateTime zoneDateTime = ZonedDateTime.now(zoneId);\nSystem.out.println(\"\u4e0a\u6d77\u65f6\u533a\u7684\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4: \" + zoneDateTime);<\/code><\/pre>\n\n\n\n
      3.5 Instant<\/code>\uff08\u65f6\u95f4\u6233\uff09<\/h4>\n\n\n\n
      Instant<\/code> \u662f Java 8 \u4e2d\u7528\u4e8e\u8868\u793a\u65f6\u95f4\u6233\u7684\u7c7b\uff0c\u5b83\u53ef\u4ee5\u8868\u793a\u4ece Unix \u7eaa\u5143\uff081970-01-01T00:00:00Z\uff09\u5f00\u59cb\u7684\u79d2\u6570\u3002<\/p>\n\n\n\n
      \/\/ \u83b7\u53d6\u5f53\u524d\u65f6\u95f4\u7684\u65f6\u95f4\u6233\nInstant nowInstant = Instant.now();\nSystem.out.println(\"\u5f53\u524d\u65f6\u95f4\u6233: \" + nowInstant);\n\n\/\/ \u83b7\u53d6\u5f53\u524d\u65f6\u95f4\u6233\u7684\u6beb\u79d2\u6570\nlong timestamp = nowInstant.toEpochMilli();\nSystem.out.println(\"\u5f53\u524d\u65f6\u95f4\u6233\uff08\u6beb\u79d2\uff09: \" + timestamp);<\/code><\/pre>\n\n\n\n
      3.6 \u683c\u5f0f\u5316\u548c\u89e3\u6790\u65e5\u671f\u65f6\u95f4<\/h4>\n\n\n\n
      DateTimeFormatter<\/code> \u662f Java 8 \u4e2d\u7528\u4e8e\u683c\u5f0f\u5316\u548c\u89e3\u6790\u65e5\u671f\u65f6\u95f4\u7684\u7c7b\u3002<\/p>\n\n\n\n
      DateTimeFormatter formatter = DateTimeFormatter.ofPattern(\"yyyy-MM-dd HH:mm:ss\");\nLocalDateTime dateTime = LocalDateTime.now();\nString formattedDate = dateTime.format(formatter);\nSystem.out.println(\"\u683c\u5f0f\u5316\u65e5\u671f\u548c\u65f6\u95f4: \" + formattedDate);\n\n\/\/ \u89e3\u6790\u5b57\u7b26\u4e32\u4e3a\u65e5\u671f\nString dateStr = \"2023-03-01 14:30:00\";\nLocalDateTime parsedDate = LocalDateTime.parse(dateStr, formatter);\nSystem.out.println(\"\u89e3\u6790\u540e\u7684\u65e5\u671f\u548c\u65f6\u95f4: \" + parsedDate);<\/code><\/pre>\n\n\n\n
      4. \u65e5\u671f\u65f6\u95f4\u7684\u6bd4\u8f83<\/strong><\/h3>\n\n\n\n
      Java \u63d0\u4f9b\u4e86\u65b9\u6cd5\u6765\u6bd4\u8f83\u4e24\u4e2a\u65e5\u671f\u65f6\u95f4\u5bf9\u8c61\u3002<\/p>\n\n\n\n
      LocalDateTime dateTime1 = LocalDateTime.of(2023, 3, 1, 14, 30);\nLocalDateTime dateTime2 = LocalDateTime.of(2023, 3, 2, 14, 30);\n\nboolean isBefore = dateTime1.isBefore(dateTime2);\nboolean isAfter = dateTime1.isAfter(dateTime2);\nboolean isEqual = dateTime1.isEqual(dateTime2);\n\nSystem.out.println(\"dateTime1 \u662f\u5426\u65e9\u4e8e dateTime2: \" + isBefore);  \/\/ true\nSystem.out.println(\"dateTime1 \u662f\u5426\u665a\u4e8e dateTime2: \" + isAfter);   \/\/ false\nSystem.out.println(\"dateTime1 \u662f\u5426\u7b49\u4e8e dateTime2: \" + isEqual);   \/\/ false<\/code><\/pre>\n\n\n\n
      5. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
        \n
      • java.util.Date<\/code>\uff1a\u65e9\u671f\u7684\u65e5\u671f\u7c7b\uff0c\u529f\u80fd\u6709\u9650\uff0c\u5df2\u7ecf\u4e0d\u63a8\u8350\u4f7f\u7528\u3002<\/li>\n\n\n\n
      • java.util.Calendar<\/code>\uff1a\u63d0\u4f9b\u66f4\u591a\u7684\u65e5\u671f\u64cd\u4f5c\u529f\u80fd\uff0c\u4f46\u4f7f\u7528\u8d77\u6765\u7a0d\u663e\u590d\u6742\u3002<\/li>\n\n\n\n
      • java.time<\/code>\uff1aJava 8 \u5f15\u5165\u7684\u65b0\u65e5\u671f\u65f6\u95f4 API\uff0c\u66f4\u73b0\u4ee3\uff0c\u529f\u80fd\u5f3a\u5927\u4e14\u7ebf\u7a0b\u5b89\u5168\uff0c\u63a8\u8350\u4f7f\u7528\u3002<\/li>\n\n\n\n
      • LocalDate<\/code>\uff1a\u8868\u793a\u65e5\u671f\uff08\u65e0\u65f6\u95f4\uff09\u3002<\/li>\n\n\n\n
      • LocalTime<\/code>\uff1a\u8868\u793a\u65f6\u95f4\uff08\u65e0\u65e5\u671f\uff09\u3002<\/li>\n\n\n\n
      • LocalDateTime<\/code>\uff1a\u8868\u793a\u65e5\u671f\u548c\u65f6\u95f4\u3002<\/li>\n\n\n\n
      • ZonedDateTime<\/code>\uff1a\u8868\u793a\u5e26\u65f6\u533a\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002<\/li>\n\n\n\n
      • Instant<\/code>\uff1a\u8868\u793a\u81ea\u7eaa\u5143\u4ee5\u6765\u7684\u65f6\u95f4\u6233\u3002<\/li>\n\n\n\n
      • DateTimeFormatter<\/code>\uff1a\u7528\u4e8e\u683c\u5f0f\u5316\u548c\u89e3\u6790\u65e5\u671f\u65f6\u95f4\u3002<\/li>\n<\/ul>\n\n\n\n
        Java 8 \u53ca\u4e4b\u540e\u7248\u672c\u63a8\u8350\u4f7f\u7528 java.time<\/code> \u5305\u6765\u5904\u7406\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u5b83\u63d0\u4f9b\u4e86\u66f4\u6e05\u6670\u3001\u66f4\u6613\u7528\u7684 API\u3002<\/p>\n\n\n\n
        \u5982\u679c<\/p>\n\n\n\n
        \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
        Java \u63d0\u4f9b\u4e86\u591a\u79cd\u5904\u7406\u65e5\u671f\u548c\u65f6\u95f4\u7684\u65b9\u5f0f\uff0c\u6700\u5e38\u7528\u7684\u65b9\u5f0f\u662f\u5728 java.util \u5305\u4e2d\u7684 Date \u7c7b\u3001Cale […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68],"tags":[],"class_list":["post-2212","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2212"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2212\/revisions"}],"predecessor-version":[{"id":2213,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2212\/revisions\/2213"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}