{"id":12614,"date":"2016-12-03T00:19:17","date_gmt":"2016-12-02T15:19:17","guid":{"rendered":"http:\/\/www.sejuku.net\/blog\/?p=12614"},"modified":"2024-05-06T11:39:52","modified_gmt":"2024-05-06T02:39:52","slug":"%e3%80%9010%e5%88%86%e3%81%a7%e3%82%8f%e3%81%8b%e3%82%8b%e3%80%91java8%e3%81%ae%e6%96%b0%e6%a9%9f%e8%83%bd%e3%82%92%e5%88%9d%e5%bf%83%e8%80%85%e5%90%91%e3%81%91%e3%81%ab%e3%82%8f%e3%81%8b%e3%82%8a","status":"publish","type":"post","link":"https:\/\/www.sejuku.net\/blog\/12614","title":{"rendered":"Java8\u306e\u65b0\u6a5f\u80fd\u3092\u5fb9\u5e95\u89e3\u8aac\uff01(\u30e9\u30e0\u30c0\u5f0f\u3001Stream\u306a\u3069)"},"content":{"rendered":"

\u3053\u3093\u306b\u3061\u306f\uff01\u30d5\u30ea\u30fc\u30e9\u30f3\u30b9\u306e\u30aa\u30fc\u30bf\u30b1\u3067\u3059\u3002<\/p>\n

Java8<\/strong><\/span>\u304c\u6700\u521d\u306b\u30ea\u30ea\u30fc\u30b9\u3055\u308c\u3066\u304b\u3089\u3059\u3067\u306b3\u5e74\u4ee5\u4e0a\u304c\u7d4c\u3061\u307e\u3057\u305f\u3002<\/p>\n

\u3057\u304b\u3057\u3001\u521d\u5fc3\u8005\u306e\u65b9\u3005\u304b\u3089<\/p>\n

\u300c\u65b0\u6a5f\u80fd\u3063\u3066\u3069\u3046\u4f7f\u3048\u3070\u3044\u3044\u306e\u304b\u5168\u7136\u308f\u304b\u3089\u306a\u3044\u300d<\/strong><\/span><\/p>\n

\u300c\u3069\u3093\u306a\u5834\u9762\u3067\u4f7f\u3048\u3070\u3044\u3044\u306e\u304b\u308f\u304b\u3089\u306a\u3044\u300d<\/strong><\/span><\/p>\n

\u3068\u3044\u3063\u305f\u304a\u56f0\u308a\u306e\u58f0\u3092\u304a\u805e\u304d\u3057\u307e\u3059\u3002<\/p>\n

\u305d\u3053\u3067\u3001\u4eca\u56de\u306f\u521d\u5fc3\u8005\u5411\u3051\u306bJava8\u306e\u65b0\u6a5f\u80fd\u3092\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac<\/strong><\/span>\u3057\u307e\u3059\uff01<\/p>\n

\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001Java8\u306e\u65b0\u6a5f\u80fd\u306b\u3064\u3044\u3066<\/p>\n

\u30fbJava\u3068\u306f
\n\u30fbJava8\u306e\u65b0\u6a5f\u80fd
\n\u30fbJava8\u306e\u74b0\u5883\u69cb\u7bc9<\/strong><\/span><\/p>\n

\u3068\u3044\u3046\u57fa\u672c\u7684\u306a\u5185\u5bb9\u304b\u3089<\/p>\n

\u30fb\u30e9\u30e0\u30c0\u5f0f
\n\u30fbStream API
\n\u30fbOptional
\n\u30fb\u65e5\u4ed8\u6642\u523bAPI
\n\u30fbinterface
\n\u30fb\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3<\/strong><\/span><\/p>\n

\u306a\u3069\u5fdc\u7528\u7684\u306a\u5185\u5bb9\u306b\u3064\u3044\u3066\u3082\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n

\u4eca\u56de\u306fJava8\u306e\u65b0\u6a5f\u80fd<\/strong><\/span>\u306b\u3064\u3044\u3066\u3001\u4f7f\u3044\u65b9\u3092\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac\u3057\u307e\u3059\uff01<\/p>\n

\u306a\u304a\u3001Java\u306e\u8a18\u4e8b\u306b\u3064\u3044\u3066\u306f\u3001\u3053\u3061\u3089<\/a>\u306b\u307e\u3068\u3081\u3066\u3044\u307e\u3059\u3002<\/p>\n

1 Java\u3068\u306f<\/h2>\n

Java\u306e\u6b74\u53f2<\/h3>\n

1990\u5e74\u4ee3\u306bSunMicrosystems\u304c\u958b\u767a\u30fb\u767a\u8868\u3057\u305f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411<\/strong><\/span>\u3068\u3044\u3046\u8003\u3048\u65b9\u3092\u53d6\u308a\u5165\u308c\u305f\u8a00\u8a9e\u3067\u3059\u3002<\/p>\n

2010\u5e74\u306bOracle\u304c\u8cb7\u53ce\u3057Oracle\u88fd\u54c1\u306e\u4e00\u3064\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n

Java\u306e\u7279\u9577<\/h3>\n

\u540c\u3058\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u8a00\u8a9e\u3067\u3042\u308bC++\u3068\u306f\u9055\u3044\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30b7\u30e7\u30f3<\/strong><\/span>\u7b49\u306e\u6a5f\u80fd\u3092\u642d\u8f09\u3057\u30e1\u30e2\u30ea\u306e\u7ba1\u7406\u3092\u307b\u307c\u610f\u8b58\u3057\u306a\u304f\u3066\u3082\u3088\u3044\u8a00\u8a9e<\/strong><\/span>\u3068\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n

\u307e\u305fJava\u306f\u5bb6\u96fb\u3084\u30e2\u30d0\u30a4\u30eb\u6a5f\u5668<\/strong><\/span>\u3092\u59cb\u3081\u3068\u3057\u305f\u30c7\u30d0\u30a4\u30b9\u306b\u642d\u8f09\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u56fd\u5185\u3067\u306f\u30d5\u30a3\u30fc\u30c1\u30e3\u30fc\u30d5\u30a9\u30f3\u3084\u30b9\u30de\u30fc\u30c8\u30d5\u30a9\u30f3\u306b\u642d\u8f09\u3055\u308c\u3066\u304a\u308a\u30a2\u30d7\u30ea\u958b\u767a\u3092\u884c\u3046\u969b\u306b\u306fJava\u8a00\u8a9e\u3092\u4f7f\u3063\u3066\u958b\u767a\u3092\u884c\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n

\u6b21\u306b2014\u5e743\u670818\u65e5\u306b\u30ea\u30ea\u30fc\u30b9\u3055\u308c\u305fJava8<\/strong><\/span>\u3067\u306f\u3044\u304f\u3064\u304b\u306e\u65b0\u6a5f\u80fd\u304c\u8ffd\u52a0<\/strong><\/span>\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u305d\u306e\u65b0\u6a5f\u80fd\u306b\u3064\u3044\u3066\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n \n

\n
\n
\n \n <\/div>\n
\n
Java\u3068\u306f\uff1f\u8a00\u8a9e\u306e\u7279\u5fb4\u3084\u4eba\u6c17\u306e\u7406\u7531\u3092\u8ab0\u3088\u308a\u3082\u308f\u304b\u308a\u3084\u3059\u304f\u5fb9\u5e95\u89e3\u8aac<\/div>\n
\u66f4\u65b0\u65e5\uff1a2025\u5e7412\u670826\u65e5<\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/a>\n \n

Java8\u306e\u65b0\u6a5f\u80fd<\/h2>\n

\u73fe\u5728\u306e\u6700\u65b0\u30d0\u30fc\u30b8\u30e7\u30f3<\/h3>\n

2017\u5e749\u6708\u306b\u30ea\u30ea\u30fc\u30b9\u3055\u308c\u305fJava9\u304c\u73fe\u5728\u306eJava\u306e\u6700\u65b0\u30d0\u30fc\u30b8\u30e7\u30f3\u3067\u3059\u3002\uff082017\u5e7411\u6708\u73fe\u5728\uff09<\/p>\n

\u4e3b\u306a\u65b0\u6a5f\u80fd<\/h3>\n

\u4eca\u56de\u306f\u3001Java8\u306e\u4e2d\u3067\u3082\u958b\u767a\u306e\u751f\u7523\u6027\u3092\u4e0a\u3052\u308b\u305f\u3081\u306e6\u3064\u306e\u65b0\u6a5f\u80fd<\/strong><\/span>\u306b\u3064\u3044\u3066\u308f\u304b\u308a\u3084\u3059\u304f\u3054\u7d39\u4ecb\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t
<\/td>\u6982\u8981<\/th>\u6a5f\u80fd\u304c\u8ffd\u52a0\u3055\u308c\u305f\u7406\u7531<\/th>\u4ed6\u8a00\u8a9e\u3067\u4f3c\u3066\u3044\u308b\u6a5f\u80fd<\/th>\n<\/tr>\n<\/thead>\n
\u30e9\u30e0\u30c0\u5f0f<\/td>\u30e1\u30bd\u30c3\u30c9\u5b9a\u7fa9\u3092\u5f0f\u3068\u3057\u3066\u6271\u3048\u308b\u6a5f\u80fd<\/td>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\u3059\u308b\u305f\u3081\u306e\u8a18\u8ff0\u3092\u7c21\u6f54\u306b\u66f8\u3051\u308b<\/td>JavaScript\u306e\u7121\u540d\u95a2\u6570
\nPHP(5.3\uff5e)\u306e\u30e9\u30e0\u30c0\u5f0f
\nC++0x\u306e\u30e9\u30e0\u30c0\u5f0f<\/td>\n<\/tr>\n
Stream API<\/td>\u914d\u5217\u3084List\u306a\u3069\u306e\u8981\u7d20\u30c7\u30fc\u30bf\u306e\u64cd\u4f5c\u3092\u7c21\u6f54\u304b\u3064\u7406\u89e3\u3057\u3084\u3059\u3044\u5f62\u3067\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u308b\u6a5f\u80fd<\/td>\u8981\u7d20\u30c7\u30fc\u30bf\u306e\u64cd\u4f5c\u3092\u7c21\u6f54\u306b\u8a18\u8ff0\u3067\u304d\u308b\u305f\u3081\u3001
\n\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u53ef\u8aad\u6027\u304c\u5411\u4e0a
\n\u30c7\u30fc\u30bf\u64cd\u4f5c\u306e\u5909\u66f4\u304c\u5bb9\u6613
\n<\/td>		PHP\u3084Ruby\u306e\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u306b\u642d\u8f09\u3055\u308c\u3066\u3044\u308bORM\u306e\u6a5f\u80fd\u306b\u8fd1\u3044<\/td>\n<\/tr>\n
Optional<\/td>\u5024\u304cnull\u3067\u3042\u308b\u304b\u3069\u3046\u304b\u3092\u7c21\u6f54\u306b\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u308b\u6a5f\u80fd<\/td>null\u30c1\u30a7\u30c3\u30af\u6642\u306e\u30df\u30b9\u3092\u6e1b\u3089\u3059\u3053\u3068\u304c\u3067\u304d\u3066\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5805\u7262\u6027\u304c\u5411\u4e0a<\/td>\u30fc<\/td>\n<\/tr>\n
\u65e5\u4ed8\u6642\u523bAPI<\/td>Date\u3001Calendar\u30af\u30e9\u30b9\u306e\u4ee3\u66ff\u3068\u3057\u3066\u3001\u6b21\u306e\u30af\u30e9\u30b9\u306a\u3069\u3092\u5c0e\u5165
\nInstant : \u65e5\u6642\uff08\u30a8\u30dd\u30c3\u30af\u79d2\uff09
\nLocalDateTime : \u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306a\u3057\u65e5\u6642
\nZonedDateTime : \u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3042\u308a\u65e5\u6642<\/td>		Date\u3001Calender\u30af\u30e9\u30b9\u3092\u6271\u3046\u306e\u306f\u9762\u5012\u3067\u6a5f\u80fd\u3082\u4e4f\u3057\u3044\u305f\u3081\u3001Java8\u304b\u3089\u65e5\u6642\u306b\u95a2\u3059\u308bAPI\u304c\u8ffd\u52a0<\/td>\u30fc<\/td>\n<\/tr>\n
interface<\/td>interface\u306edefault\u30e1\u30bd\u30c3\u30c9\u3001static\u30e1\u30bd\u30c3\u30c9\u3092\u5c0e\u5165<\/td>\u5b9f\u88c5\u3059\u308b\u5fc5\u8981\u306e\u306a\u3044\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u66f8\u304f\u5fc5\u8981\u304c\u306a\u304f\u306a\u308b
\ninterface\u306b\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3057\u305f\u6642\u306b\u3001\u65e2\u5b58\u306e\u5b9f\u88c5\u30af\u30e9\u30b9\u306b\u5f71\u97ff\u304c\u306a\u3044<\/td>		\u30fc<\/td>\n<\/tr>\n
\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3<\/td>\u5909\u6570\u306e\u578b\u3084\u30b8\u30a7\u30cd\u30ea\u30af\u30b9\u306e\u578b\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u304c\u3064\u3051\u3089\u308c\u308b\u6a5f\u80fd\u3092\u8ffd\u52a0<\/td>\u578b\u306e\u30c1\u30a7\u30c3\u30af\u306a\u3069\u3092\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u884c\u3044\u3001\u60f3\u5b9a\u5916\u306e\u30a8\u30e9\u30fc\u3092\u907f\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u308b<\/td>\u30fc<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

\u305d\u308c\u305e\u308c\u306e\u5185\u5bb9\u306b\u3064\u3044\u3066\u306f\u3001\u5f8c\u307b\u3069\u8a73\u3057\u304f\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n

Java8\u306e\u74b0\u5883\u69cb\u7bc9<\/h2>\n

\u307e\u305a\u306fJava8\u306e\u958b\u767a\u74b0\u5883\u3092\u69cb\u7bc9\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n

\u3053\u308c\u304b\u3089\u4f7f\u3046\u30d1\u30bd\u30b3\u30f3\u306b\u3053\u308c\u307e\u3067Java\u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u305f\u3053\u3068\u304c\u306a\u3051\u308c\u3070\u3001\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9\u304b\u3089\u59cb\u3081\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n

\u4ee5\u524d\u306b\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u305f\u3053\u3068\u304c\u3042\u308b\u3001\u3082\u3057\u304f\u306f\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u305f\u304b\u3069\u3046\u304b\u308f\u304b\u3089\u306a\u3044\u5834\u5408\u306f\u30a2\u30c3\u30d7\u30c7\u30fc\u30c8\u306b\u3064\u3044\u3066\u306e\u8aac\u660e\u304b\u3089\u9032\u3081\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n

\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9<\/h3>\n

Java8\u3092\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9\u3057\u3066\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3059\u308b\u65b9\u6cd5\u306b\u3064\u3044\u3066\u306f\u3001\u3053\u3061\u3089\u3067\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u53c2\u8003\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n \n

\n
\n
\n \n <\/div>\n
\n
\u3010Java\u521d\u5fc3\u8005\u5fc5\u898b\uff01\u3011Java\u306e\u958b\u767a\u74b0\u5883\u3092\u69cb\u7bc9\u3059\u308b\u65b9\u6cd5\u3092\u89e3\u8aac\uff01<\/div>\n
\u66f4\u65b0\u65e5\uff1a2025\u5e7412\u670826\u65e5<\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/a>\n \n \n
\n
\n
\n \n <\/div>\n
\n
\u3010Mac\u7de8\u3011Java\u306e\u958b\u767a\u74b0\u5883\u3092\u7c21\u5358\u306b\u4e00\u62ec\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3059\u308b\u65b9\u6cd5<\/div>\n
\u66f4\u65b0\u65e5\uff1a2025\u5e7412\u670826\u65e5<\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/a>\n \n

\u30a2\u30c3\u30d7\u30c7\u30fc\u30c8<\/h3>\n

Java8\u306b\u30a2\u30c3\u30d7\u30c7\u30fc\u30c8\u3059\u308b\u305f\u3081\u306b\u306f\u73fe\u5728\u30d1\u30bd\u30b3\u30f3\u306b\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3055\u308c\u3066\u3044\u308bJava\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u304cJava8\u304bJava7\u4ee5\u524d\u304b\u78ba\u8a8d<\/strong><\/span>\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u3053\u3053\u3067\u306f\u3001\u4f7f\u3046\u30d1\u30bd\u30b3\u30f3\u306eOS\u306fWindows10\u306e\u5834\u5408\u3092\u4ee3\u8868\u4f8b\u3068\u3057\u3066\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n

Java\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u3092\u78ba\u8a8d\u3059\u308b\u65b9\u6cd5\u306f\u4ee5\u4e0b\u306e\u3068\u304a\u308a\u3067\u3059\u3002<\/p>\n

Windows 10\uff0d\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u78ba\u8a8d
\n1.\u300c\u30b9\u30bf\u30fc\u30c8\u300d\u3092\u30af\u30ea\u30c3\u30af\u3057\u307e\u3059\u3002
\n2.\u300c\u8a2d\u5b9a\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n3.\u300c\u30b7\u30b9\u30c6\u30e0\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n4.\u300c\u30a2\u30d7\u30ea\u3068\u6a5f\u80fd\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n5.\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u4e00\u89a7\u304b\u3089Java\u3092\u63a2\u3057\u51fa\u3057\u3066\u30d0\u30fc\u30b8\u30e7\u30f3\u3092\u78ba\u8a8d\u3057\u307e\u3059<\/p>\n

\"Java8check\"<\/p>\n

\u3053\u306e\u753b\u50cf\u3067\u306fJava8\u304c\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n

Java7\u4ee5\u524d\u304c\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f\u3001Java\u3092\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb<\/strong><\/span>\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

Java\u3092\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3067\u304d\u305f\u3089\u3001\u524d\u7ae0\u306e\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9\u306e\u65b9\u6cd5\u3092\u53c2\u8003\u306b\u3057\u3066Java8\u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n

Windows 10\uff0d\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb
\n1.\u300c\u30b9\u30bf\u30fc\u30c8\u300d\u3092\u30af\u30ea\u30c3\u30af\u3057\u307e\u3059\u3002
\n2.\u300c\u8a2d\u5b9a\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n3.\u300c\u30b7\u30b9\u30c6\u30e0\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n4.\u300c\u30a2\u30d7\u30ea\u3068\u6a5f\u80fd\u300d\u3092\u9078\u629e\u3057\u307e\u3059
\n5.\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u9078\u629e\u3057\u3001\u300c\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u300d\u30dc\u30bf\u30f3\u3092\u30af\u30ea\u30c3\u30af\u3057\u307e\u3059\u3002
\n6.\u30d7\u30ed\u30f3\u30d7\u30c8\u306b\u5f93\u3063\u3066\u3001\u30a2\u30f3\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3092\u5b8c\u4e86\u3057\u307e\u3059<\/p>\n

\u516c\u5f0f\u53c2\u8003\u30b5\u30a4\u30c8
\nhttps:\/\/java.com\/ja\/download\/faq\/remove_olderversions.xml<\/a><\/p>\n

\u30e9\u30e0\u30c0\u5f0f<\/h2>\n

\u30e9\u30e0\u30c0\u5f0f\u3068\u306f<\/h3>\n

\u30e9\u30e0\u30c0\u5f0f<\/strong><\/span>\u3068\u306f\u4e00\u8a00\u3067\u3044\u3046\u3068\u3001\u300c\u30e1\u30bd\u30c3\u30c9\u5b9a\u7fa9\u3092\u5f0f\u3068\u3057\u3066\u6271\u3048\u308b\u6a5f\u80fd\u300d<\/strong><\/span>\u306e\u3053\u3068\u3067\u3059\u3002<\/p>\n

\u95a2\u6570\u578b\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\u3059\u308b\u305f\u3081\u306e\u8a18\u8ff0\u3092\u7c21\u6f54\u306b\u66f8\u3051\u308b<\/strong><\/span>\u30e1\u30ea\u30c3\u30c8\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u3061\u306a\u307f\u306b\u3001\u95a2\u6570\u578b\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9<\/strong><\/span>\u3068\u306f\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u30921\u3064\u6301\u3064\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9<\/strong><\/span>\u306e\u3053\u3068\u3067\u3059\u3002<\/p>\n

\u307e\u305f\u30e9\u30e0\u30c0\u5f0f\u3068\u3044\u3046\u4ed5\u7d44\u307f\u306fJavaScript\u3001PHP\u3001C++\u3067\u3082\u63a1\u7528\u304c\u9032\u3093\u3067\u3044\u307e\u3059\u3002<\/p>\n

Java8\u3067\u30e9\u30e0\u30c0\u5f0f\u304c\u5b9f\u88c5\u3055\u308c\u305f\u80cc\u666f\u306b\u306f\u6642\u4ee3\u306e\u6d41\u308c\u306b\u6cbf\u3046\u3082\u306e\u3068\u3044\u3063\u305f\u3053\u3068\u3082\u8003\u3048\u3089\u308c\u308b\u306e\u3067\u306f\u306a\u3044\u3067\u3057\u3087\u3046\u304b\uff1f<\/p>\n

\u30e9\u30e0\u30c0\u5f0f\u306e\u4f7f\u3044\u65b9<\/h3>\n

\u30e9\u30e0\u30c0\u5f0f\u306e\u57fa\u672c\u7684\u306a\u69cb\u6587\u306f\u3001\u30a2\u30ed\u30fc\u6f14\u7b97\u5b50<\/strong><\/span>(->)\u3092\u4f7f\u3063\u3066\u4e0b\u8a18\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n

\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u540d \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u540d = (\u5f15\u65701, \u5f15\u65702, \u30fb\u30fb\u30fb) -> {return \u51e6\u7406\u5185\u5bb9};\r\n<\/pre>\n
\u306a\u304a\u3001\u5f15\u6570\u306e\u578b\u306f\u8a18\u8ff0\u3059\u308b\u5fc5\u8981\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u5f15\u6570\u306e\u578b\u306f\u30b3\u30f3\u30d1\u30a4\u30e9\u30fc\u306b\u3088\u3063\u3066\u5224\u65ad<\/strong><\/span>\u3055\u308c\u308b\u306e\u3067\u3001\u8a18\u8ff0\u3059\u308b\u5fc5\u8981\u304c\u306a\u3044\u306e\u304c\u30e9\u30e0\u30c0\u5f0f\u306e\u8a18\u8ff0\u306e\u7279\u5fb4\u306e\u4e00\u3064\u3067\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u3060\u304b\u3089\u3068\u8a00\u3063\u3066\u3001\u5f93\u6765\u306e\u8a18\u8ff0\u69d8\u5f0f\u306e\u3088\u3046\u306b\u578b\u3092\u8a18\u8ff0\u3057\u3066\u3082\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308b\u3053\u3068\u3082\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u30e9\u30e0\u30c0\u5f0f\u306e\u5f15\u6570\u304c\u306a\u3044\u5834\u5408\u3001\u3042\u308b\u5834\u5408\u3001\u623b\u308a\u5024\u304c\u3042\u308b\u5834\u5408\u306e\u8a18\u8ff0\u306b\u3064\u3044\u3066\u8868\u306b\u307e\u3068\u3081\u307e\u3057\u305f\u3002<\/p>\n\n\n\n\n\t\n\n\t\n\t\n\t
<\/td>\u69cb\u6587<\/th>\u8a18\u8ff0\u4f8b<\/th>\n<\/tr>\n<\/thead>\n
\u5f15\u6570\u304c\u306a\u3044\u5834\u5408<\/td>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u540d \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u540d = () -> \u51e6\u7406;<\/td>InterfaceTest it = () -> System.out.println(\"Hello World\");<\/td>\n<\/tr>\n
\u5f15\u6570\u304c\u3042\u308b\u5834\u5408<\/td>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u540d \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u540d = (\u5909\u65701, \u5909\u65702, \u30fb\u30fb\u30fb) -> \u51e6\u7406;<\/td>InterfaceTest it = a -> System.out.println(a.length());<\/td>\n<\/tr>\n
\u623b\u308a\u5024\u304c\u3042\u308b\u5834\u5408<\/td>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u540d \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u540d = () -> {return \u51e6\u7406;};<\/td>InterfaceTest it = () -> {return 0;};<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n
\u5f15\u6570\u304c\u306a\u3044\u5834\u5408<\/h4>\n
Java7\u307e\u3067\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3057\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n
Java7\uff1a<\/strong><\/p>\n
\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\r\ninterface InterfaceTest {\r\n\t\/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\r\n\tpublic void method();\r\n}\r\n\r\npublic class Main {\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\t\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u5b9f\u88c5\r\n\t\tInterfaceTest it = new InterfaceTest() {\r\n\t\t\tpublic void method() {\r\n\t\t\t\tSystem.out.println(\"Hello World\");\r\n\t\t\t}\r\n\t\t};\r\n\t\tit.method();\r\n\t}\r\n\r\n}\r\n<\/pre>\n
\u30e9\u30e0\u30c0\u5f0f\u3092\u4f7f\u3046\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\r\ninterface InterfaceTest {\r\n\t\/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\r\n\tpublic void method();\r\n}\r\n\r\npublic class Main {\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tInterfaceTest it = () -> System.out.println(\"Hello World\");\r\n\t\tit.method();\r\n\t}\r\n\r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
Hello World\r\n<\/pre>\n
\u30a2\u30ed\u30fc\u6f14\u7b97\u5b50(->)\u306e\u5de6\u5074\u306e\u62ec\u5f27\u306f\u30e1\u30bd\u30c3\u30c9\u306e\u5f15\u6570\u3092\u6e21\u3059\u62ec\u5f27<\/strong><\/span>\u306b\u76f8\u5f53\u3057\u307e\u3059\u3002<\/p>\n
\u305d\u308c\u3092\u30a2\u30ed\u30fc\u6f14\u7b97\u5b50(->)\u3067\u3064\u306a\u3052\u3066\u53f3\u5074\u306b\u51e6\u7406\u3092\u66f8\u304f<\/strong><\/span>\u3053\u3068\u3067\u30e9\u30e0\u30c0\u5f0f\u3068\u3057\u3066\u6210\u7acb\u3057\u307e\u3059\u3002<\/p>\n
\u4eca\u56de\u306e\u5834\u5408\u306fSystem.out.println\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3093\u3067\u3044\u307e\u3059\u3002<\/p>\n
\u5f15\u6570\u304c\u3042\u308b\u5834\u5408<\/h4>\n
\u30e9\u30e0\u30c0\u5f0f\u306b\u306f\u5f15\u6570\u3092\u6e21\u3059\u3053\u3068\u304c\u53ef\u80fd<\/strong><\/span>\u3067\u3059\u3002<\/p>\n
\u307e\u305f\u3001\u5f15\u6570\u304c1\u3064\u306e\u5834\u5408\u306f\u5909\u6570\u3092\u56f2\u3080\u62ec\u5f27(( ))\u3092\u7701\u7565<\/strong><\/span>\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u3055\u3089\u306b\u3055\u3089\u306b\u3001\u4e0a\u8a18\u306e\u4f8b\u306e\u3088\u3046\u306b\u578b\u540d\u306e\u8a18\u8ff0\u3082\u7701\u7565<\/strong><\/span>\u3059\u308b\u3053\u3068\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n
\u306a\u304a\u3001\u578b\u540d\u306e\u8a18\u8ff0\u306e\u7701\u7565\u306b\u3064\u3044\u3066\u306f\u5f15\u6570\u304c\u5e7e\u3064\u3042\u308b\u5834\u5408\u3067\u3082\u7701\u7565<\/strong><\/span>\u3059\u308b\u3053\u3068\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\r\ninterface InterfaceTest{\r\n    \/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\r\n    public void method(String s);\r\n}\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        InterfaceTest it = a -> System.out.println(a.length());\r\n        it.method(\"Hello World\");\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
11\r\n<\/pre>\n
\u623b\u308a\u5024\u304c\u3042\u308b\u5834\u5408<\/h4>\n
\u30e9\u30e0\u30c0\u5f0f\u3067\u306f\u623b\u308a\u5024\u3092\u8fd4\u3059\u3088\u3046\u306a\u3053\u3068\u3082\u53ef\u80fd\u3067\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\r\ninterface InterfaceTest{\r\n    \/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\r\n    public int method();\r\n}\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        InterfaceTest it = () -> {return 1;};\r\n        System.out.println(it.method());\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
1\r\n<\/pre>\n
3\u3064\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u4f7f\u3046\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u30e9\u30e0\u30c0\u5f0f\u306b\u3064\u3044\u3066\u3001\u3053\u3061\u3089\u3067\u3082\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u3044\u308b\u306e\u3067\u53c2\u8003\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u306d\uff01
\n            \n                
\n                
\n                    
\n                    \n                    <\/div>\n                    
\n                    
\u3010Java\u5165\u9580\u3011Java8\u306e\u30e9\u30e0\u30c0\u5f0f\u306e\u4f7f\u3044\u65b9\u3068\u30e1\u30ea\u30c3\u30c8\u3068\u306f(Stream API)<\/div>\n                    
\u66f4\u65b0\u65e5\uff1a2024\u5e745\u67086\u65e5<\/div>\n                    <\/div>\n                <\/div>\n                <\/div>\n            <\/a>\n            <\/p>\n
Stream API<\/h2>\n
Stream API\u3068\u306f<\/h3>\n
Java7\u307e\u3067\u306e\u914d\u5217\u3084List\u306a\u3069\u306e\u8981\u7d20\u30c7\u30fc\u30bf\u306e\u64cd\u4f5c\u306ffor<\/strong><\/span>\u3084while<\/strong><\/span>\u3092\u7528\u3044\u3066\u51e6\u7406\u3057\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n
\u3053\u308c\u304b\u3089\u89e3\u8aac\u3092\u884c\u3046Stream API<\/strong><\/span>\u3068\u3044\u3046\u6a5f\u80fd\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001\u8981\u7d20\u30c7\u30fc\u30bf\u306e\u64cd\u4f5c\u3092\u7c21\u6f54\u304b\u3064\u7406\u89e3\u3057\u3084\u3059\u3044\u5f62\u3067\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n
\u7c21\u6f54\u304b\u3064\u7406\u89e3\u3057\u3084\u3059\u3044\u5f62\u3067\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u308b\u305f\u3081\u3001\u53ef\u8aad\u6027\u304c\u5411\u4e0a<\/strong><\/span>\u3057\u307e\u3059\u3002<\/p>\n
\u307e\u305f\u7c21\u6f54\u304b\u3064\u7406\u89e3\u3057\u3084\u3059\u3044\u305f\u3081\u3001\u30c7\u30fc\u30bf\u64cd\u4f5c\u306e\u6761\u4ef6\u3082\u5909\u66f4\u3057\u3084\u3059\u304f<\/strong><\/span>\u306a\u308a\u307e\u3059\u3002<\/p>\n
Stream API\u306e\u4f7f\u3044\u65b9<\/h3>\n
\u3088\u304f\u4f7f\u3046\u3068\u601d\u308f\u308c\u308bStream API\u306b\u3064\u3044\u3066\u8868\u306b\u307e\u3068\u3081\u307e\u3057\u305f\u3002<\/p>\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t
Stream API<\/th>\u8aac\u660e<\/th>\u8a18\u8ff0\u4f8b<\/th>\n<\/tr>\n<\/thead>\n
map<\/td>\u56db\u5247\u6f14\u7b97\u306a\u3069\u306e\u4e00\u6642\u7684\u306a\u51e6\u7406<\/td>list.stream().map(x -> x * 2)<\/td>\n<\/tr>\n
filter<\/td>\u6761\u4ef6\u3092\u6e80\u305f\u3059\u5834\u5408\u3060\u3051\u306e\u51e6\u7406<\/td>list.stream().filter(x -> x >= 2)<\/td>\n<\/tr>\n
sorted<\/td>\u9806\u756a\u306b\u4e26\u3079\u308b\u51e6\u7406<\/td>list.stream().sorted()<\/td>\n<\/tr>\n
distinct<\/td>\u91cd\u8907\u3059\u308b\u5024\u3092\u6392\u9664\u3059\u308b\u51e6\u7406<\/td>list.stream().distinct()<\/td>\n<\/tr>\n
limit<\/td>\u6271\u3046\u30c7\u30fc\u30bf\u4ef6\u6570\u3092\u5236\u9650\u3059\u308b\u51e6\u7406<\/td>list.stream().limit(3)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n
\u3053\u308c\u3089\u306fStream API\u306e\u307b\u3093\u306e\u4e00\u90e8\u3067\u3059\u3002<\/p>\n
map\u3067\u306e\u8981\u7d20\u306e\u5024\u3092\u66f8\u304d\u63db\u3048<\/h4>\n
\u8981\u7d20\u306e\u5024\u3092\u4e00\u6642\u7684\u306b\u5909\u5316\u3055\u305b\u3066\u5909\u5316\u5f8c\u306e\u5024\u3092\u51fa\u529b\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.List;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        List<Integer> list = Arrays.asList(1, 2, 3);\r\n        list.stream().map(x -> x * 2).forEach(System.out::println);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
2\r\n4\r\n6\r\n<\/pre>\n
filter\u3067\u306e\u9078\u5225<\/h4>\n
filter<\/strong><\/span>\u3092\u4f7f\u7528\u3057\u3066\u3001\u8981\u7d20\u306e\u5024\u304c2\u4ee5\u4e0a\u306e\u5408\u8a08\u5024\u3092\u6c42\u3081\u308b\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.List;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5);\r\n        int total = list.stream().filter(x -> x >= 2).mapToInt(x -> x).sum();\r\n        System.out.println(\"Total : \" + total);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
Total : 14\r\n<\/pre>\n
\u3053\u308c\u3068\u540c\u3058\u51e6\u7406\u3092Java7\u3067\u884c\u3046\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
Java7\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.List;\r\n\r\npublic class Main {\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tList<Integer> list = Arrays.asList(1, 2, 3, 4, 5);\r\n\t\tint total = 0;\r\n\t\tfor (Integer x : list) {\r\n\t\t\tif (x >= 2) {\r\n\t\t\t\ttotal += x;\r\n\t\t\t}\r\n\t\t}\r\n\t\tSystem.out.println(\"Total : \" + total);\r\n\t}\r\n\r\n}\r\n<\/pre>\n
\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u7c21\u6f54\u3067\u308f\u304b\u308a\u3084\u3059\u304f<\/strong><\/span>\u306a\u3063\u3066\u3044\u308b\u306e\u304c\u308f\u304b\u308a\u307e\u3059\u3002<\/p>\n
sorted\u3067\u306e\u4e26\u3073\u66ff\u3048<\/h4>\n
\u8981\u7d20\u306e\u5024\u3092\u964d\u9806\u306b\u30bd\u30fc\u30c8<\/strong><\/span>\u3059\u308b\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002<\/p>\n
sorted<\/strong><\/span>\u306e\u5f15\u6570\u3092\u7a7a\u306b\u3057\u305f\u5834\u5408\u306f\u6607\u9806\u306b\u30bd\u30fc\u30c8<\/strong><\/span>\u3055\u308c\u307e\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.Comparator;\r\nimport java.util.List;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        List<Integer> list = Arrays.asList(5, 1, 4, 3, 2);\r\n        list.stream().sorted(Comparator.reverseOrder()).forEach(System.out::println);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
5\r\n4\r\n3\r\n2\r\n1\r\n<\/pre>\n
distinct\u3067\u306e\u91cd\u8907\u6392\u9664<\/h4>\n
\u8981\u7d20\u306e\u5024\u306b\u91cd\u8907\u3059\u308b\u5024\u304c\u3042\u308c\u3070\u9664\u304f<\/strong><\/span>\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.List;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        List<Integer> list = Arrays.asList(5, 1, 4, 5, 5);\r\n        list.stream().distinct().forEach(System.out::println);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
5\r\n1\r\n4\r\n<\/pre>\n
distinct<\/strong><\/span>\u3092\u547c\u3073\u51fa\u3059\u3053\u3068\u3067\u91cd\u8907\u3059\u308b\u30c7\u30fc\u30bf\u3092\u9664\u3044\u3066\u51fa\u529b<\/strong><\/span>\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u3066\u3044\u307e\u3059\u3002<\/p>\n
limit\u3067\u306e\u30c7\u30fc\u30bf\u5236\u9650<\/h4>\n
limit<\/strong><\/span>\u3092\u4f7f\u3046\u3053\u3068\u3067\u6271\u3046\u30c7\u30fc\u30bf\u4ef6\u6570\u3092\u5236\u9650<\/strong><\/span>\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Arrays;\r\nimport java.util.List;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        List<Integer> list = Arrays.asList(1, 2, 3, 4, 5);\r\n        list.stream().limit(3).forEach(System.out::println);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
1\r\n2\r\n3\r\n<\/pre>\n
\u4e0a\u8a18\u306e\u4f8b\u3067\u306f5\u3064\u306e\u8981\u7d20\u304b\u30893\u3064\u306b\u7d5e\u3063\u3066\u8868\u793a\u3092\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u306a\u304a\u3001Stream API\u306e\u4f7f\u3044\u65b9\u306b\u3064\u3044\u3066\u306f\u3001\u3053\u3061\u3089\u3067\u3082\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u3044\u308b\u306e\u3067\u53c2\u8003\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u306d\uff01
\n            \n                
\n                
\n                    
\n                    \n                    <\/div>\n                    
\n                    
\u3010Java\u5165\u9580\u3011Java8\u306e\u30e9\u30e0\u30c0\u5f0f\u306e\u4f7f\u3044\u65b9\u3068\u30e1\u30ea\u30c3\u30c8\u3068\u306f(Stream API)<\/div>\n                    
\u66f4\u65b0\u65e5\uff1a2024\u5e745\u67086\u65e5<\/div>\n                    <\/div>\n                <\/div>\n                <\/div>\n            <\/a>\n            <\/p>\n
Optional<\/h2>\n
Optional\u3068\u306f<\/h3>\n
\u5024\u306e\u306a\u3044\u72b6\u614b\u3092\u300cnull\u300d\u3068\u8a00\u3044\u307e\u3059\u304c\u3001\u958b\u767a\u4e2d\u306fnull\u304c\u539f\u56e0\u3067\u610f\u56f3\u3057\u3066\u3044\u306a\u3044\u30a8\u30e9\u30fc\u304c\u8d77\u3053\u308b<\/strong><\/span>\u3053\u3068\u304c\u591a\u3044\u3067\u3059\u3002<\/p>\n
\u305d\u306e\u305f\u3081\u3001\u30a8\u30e9\u30fc\u3092\u672a\u7136\u306b\u9632\u3050\u305f\u3081\u306bnull\u30c1\u30a7\u30c3\u30af\u306e\u51e6\u7406\u3092\u66f8\u304f\u5fc5\u8981<\/strong><\/span>\u304c\u3042\u308a\u307e\u3057\u305f\u3002<\/p>\n
\u4e00\u822c\u7684\u306b\u306fif\u6587\u3092\u4f7f\u3063\u3066\u5909\u6570\u5185\u306e\u5024\u304cnull\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d<\/strong><\/span>\u3057\u307e\u3059\u3002<\/p>\n
\u3057\u304b\u3057\u3001\u3053\u306eOptional<\/strong><\/span>\u3092\u4f7f\u3046\u3068\u3001\u5024\u304cnull\u3067\u3042\u308b\u304b\u3069\u3046\u304b\u3092\u7c21\u6f54\u306b\u66f8\u304f<\/strong><\/span>\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
if\u6587\u306e\u30d6\u30ed\u30c3\u30af\u3092\u66f8\u304b\u306a\u304f\u3066\u3082null\u30c1\u30a7\u30c3\u30af\u304c\u8a18\u8ff0\u3067\u304d\u308b\u305f\u3081\u3001if\u3092\u30cd\u30b9\u30c8\u3055\u305b\u308b\u3053\u3068\u3082\u6975\u529b\u907f\u3051\u3066\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u307e\u305f\u306f\u3063\u304d\u308a\u3068\u300c\u5024\u304c\u5165\u3063\u3066\u3044\u306a\u3044\u5834\u5408\u300d\u3068\u3044\u3046\u51e6\u7406\u3092\u793a\u3059\u3053\u3068\u304c\u3067\u308b\u305f\u3081\u3001if\u306b\u3088\u308bnull\u30c1\u30a7\u30c3\u30af\u6642\u306e\u30df\u30b9\u3092\u6e1b\u3089\u3059\u3053\u3068\u3082\u53ef\u80fd\u306b\u306a\u308a\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5805\u7262\u6027\u3082\u5411\u4e0a<\/strong><\/span>\u3059\u308b\u3068\u601d\u308f\u308c\u307e\u3059\u3002<\/p>\n
Optional\u306e\u4f7f\u3044\u65b9<\/h3>\n
Optional\u30af\u30e9\u30b9\u306eifPresent<\/strong><\/span>\u3068orElse<\/strong><\/span>\u306e\u4f7f\u3044\u65b9\u3092\u3001Java7\u307e\u3067\u3068\u6bd4\u8f03\u3057\u3066\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
ifPresent\u306e\u4f7f\u3044\u65b9<\/h4>\n
Java7\uff1a<\/strong><\/p>\n
public class Main {\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = null;\r\n\t\tif (str != null) {\r\n\t\t\tSystem.out.println(str);\r\n\t\t}\r\n\t}\r\n\r\n}\r\n<\/pre>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Optional;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        String str = null;\r\n        Optional<String> value = Optional.ofNullable(str);\r\n        value.ifPresent(System.out::println);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u4e0a\u8a18\u306e\u4f8b\u3067\u306f\u6587\u5b57\u5217\u30af\u30e9\u30b9\u3067\u3042\u308bstr\u306bnull\u3092\u4ee3\u5165\u3057\u3001\u30c1\u30a7\u30c3\u30af\u306b\u7528\u3044\u308b\u305f\u3081\u306e\u5909\u6570value\u3092\u5b9a\u7fa9\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
ifPresent<\/strong><\/span>\u3092\u4f7f\u3046\u3053\u3068\u3067null\u3067\u306a\u3044\u5834\u5408\u306e\u307f\u62ec\u5f27\u5185\u306e\u51e6\u7406\u3092\u884c\u3046<\/strong><\/span>\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
\u4e0a\u8a18\u3092\u5b9f\u884c\u3059\u308b\u3068\u4f55\u3082\u8868\u793a\u3055\u308c\u307e\u305b\u3093\u304c\u3001str = null\u306e\u90e8\u5206\u3092str = \u201cabc\u201d\u3068\u5909\u3048\u308b\u3053\u3068\u3067\u5b9f\u884c\u3059\u308b\u3068abc\u3068\u8868\u793a\u3055\u308c\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
orElse\u306e\u4f7f\u3044\u65b9<\/h4>\n
Java7\uff1a<\/strong><\/p>\n
public class Main {\r\n\r\n\tpublic static void main(String[] args) {\r\n\t\tString str = null;\r\n\t\tif (str == null) {\r\n\t\t\tstr = \"abc\";\r\n\t\t}\r\n\t\tSystem.out.println(str);\r\n\t}\r\n\r\n}\r\n<\/pre>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Optional;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        String str = null;\r\n        Optional<String> value = Optional.ofNullable(str);\r\n        str = value.orElse(\"abc\");\r\n        System.out.println(str);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
abc\r\n<\/pre>\n
\u3053\u306e\u4f8b\u3067\u306forElse<\/strong><\/span>\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001String\u578b\u306e\u5909\u6570str\u304cnull\u3067\u3060\u3063\u305f\u5834\u5408\u306b\u300cabc\u300d\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u65b9\u6cd5\u3092\u4f7f\u3046\u3068NullPointer<\/strong><\/span>\u30a2\u30af\u30bb\u30b9\u3092\u9632\u3050\u3053\u3068\u304c\u3067\u304d\u3001\u51e6\u7406\u3092\u7d9a\u3051\u308b\u3053\u3068\u304c\u53ef\u80fd<\/strong><\/span>\u3067\u3059\u3002<\/p>\n
orElse\u306e\u5f15\u6570\u306b\u30e9\u30e0\u30c0\u5f0f\u3092\u4f7f\u3046\u5834\u5408<\/h4>\n
\u524d\u9805\u306eorElse\u3092\u4f7f\u3063\u305f\u4f8b\u306e\u5fdc\u7528\u3068\u3057\u3066\u3001\u4f55\u304b\u51e6\u7406\u3092\u3055\u305b\u3066\u304b\u3089\u5024\u3092\u8fd4\u3057\u305f\u3044\u3068\u3044\u3046\u5834\u5408\u3082\u3042\u308b\u304b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
\u305d\u306e\u5834\u5408\u306forElseGet<\/strong><\/span>\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3044\u3001\u6b21\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3057\u307e\u3059\u3002<\/p>\n
Java8\uff1a<\/strong><\/p>\n
import java.util.Optional;\r\nimport java.util.Random;\r\n \r\npublic class Main {\r\n \r\n    public static void main(String[] args) {\r\n        String str = null;\r\n        Optional<String> value = Optional.ofNullable(str);\r\n        str = value.orElseGet(\r\n          () -> {\r\n            Random rnd = new Random();\r\n            int ran = rnd.nextInt(10);\r\n            return \"\" + ran;\r\n          }\r\n        );\r\n        System.out.println(str);\r\n    }\r\n \r\n}\r\n<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/strong><\/p>\n
1\r\n<\/pre>\n
\u4e0a\u8a18\u306e\u4f8b\u3067\u306forElseGet<\/strong><\/span>\u3092\u7528\u3044\u3066\u30e9\u30e0\u30c0\u5f0f\u5185\u3067\u4e71\u6570\u3092\u751f\u6210\u3055\u305b\u6587\u5b57\u5217\u3068\u3057\u3066\u8fd4\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u3053\u308c\u3092\u5b9f\u884c\u3059\u308b\u305f\u3073\u306b\u4e71\u6570\u304c\u751f\u6210\u3055\u308c\u308b\u306e\u3067\u6bce\u56de\u9055\u3046\u5024\u304c\u8868\u793a\u3055\u308c\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
\u65e5\u4ed8\u6642\u523bAPI<\/h2>\n
Java8\u6642\u4ee3\u306e\u65e5\u4ed8\u306e\u53d6\u6271\u306b\u3064\u3044\u3066<\/h3>\n
\u5143\u3005Java7\u307e\u3067\u306e\u65e5\u4ed8\u3001\u6642\u9593\u306e\u6271\u3044\u306f\u3068\u3066\u3082\u9762\u5012\u304f\u3055\u3044\u3082\u306e\u3067\u3057\u305f\u3002<\/p>\n
Date<\/strong><\/span>\u3084Calender<\/strong><\/span>\u30af\u30e9\u30b9\u3092\u6271\u3046\u306e\u306f\u9762\u5012\u3067\u6a5f\u80fd\u3082\u4e4f\u3057\u3044\u305f\u3081\u3001Java\u30d7\u30ed\u30b0\u30e9\u30de\u304b\u3089\u306f\u656c\u9060\u3055\u308c\u308b\u5143\u3068\u306a\u3063\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n
\u3053\u308c\u306b\u5bfe\u3057\u3066\u3001Java8\u3067\u306f\u65e5\u6642\u30af\u30e9\u30b9\u306e\u6a5f\u80fd\u304c\u5f37\u5316<\/strong><\/span>\u3055\u308c\u3044\u308d\u3044\u308d\u306a\u51e6\u7406\u304c\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n
\u65b0\u3057\u304f\u8ffd\u52a0\u3055\u308c\u305f\u30af\u30e9\u30b9\u306f\u4ee5\u4e0b\u306e\u3068\u304a\u308a\u3067\u3059\u3002<\/p>\n