{"id":689,"date":"2013-04-06T06:00:20","date_gmt":"2013-04-05T21:00:20","guid":{"rendered":"http:\/\/yucchi.jp\/blog\/?p=689"},"modified":"2013-04-24T19:52:13","modified_gmt":"2013-04-24T10:52:13","slug":"jdk8-lambda-%e3%81%9d%e3%81%ae%e4%bb%96%e3%81%84%e3%82%8d%e3%81%84%e3%82%8d-%e3%81%aa%e3%82%93%e3%81%a7%e3%82%82%e3%81%84%e3%81%84%e3%81%8b%e3%82%89%e5%8b%95%e3%81%8b%e3%81%97%e3%81%a6%e3%81%bf-4","status":"publish","type":"post","link":"http:\/\/yucchi.jp\/blog\/?p=689","title":{"rendered":"JDK8 Lambda \u305d\u306e\u4ed6\u3044\u308d\u3044\u308d \u306a\u3093\u3067\u3082\u3044\u3044\u304b\u3089\u52d5\u304b\u3057\u3066\u307f\u308b \u305d\u306e\uff15"},"content":{"rendered":"<style type=\"text\/css\">\n<!--\ntable {color: #000000; background-color: #e9e8e2; font-family: \u3086\u305f\u307d\u3093\uff08\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\uff09}\n-->\n<\/style>\n<p>\u4eca\u65e5\u3082\u3057\u3064\u3053\u304f JDK8 \u306e\u65b0\u6a5f\u80fd\u3092\u8a66\u3057\u3066\u307f\u307e\u3059\u3002<\/p>\n<p>\u4eca\u56de\u306f\u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269\u3092\u8868\u793a\u3055\u305b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<p>\u3067\u306f\u6628\u65e5\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4e0b\u8a18\u306e\u3088\u3046\u306b\u5909\u66f4\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<table width=\"100%\">\n<tbody>\n<tr>\n<td align=\"left\">mylambdaexamples\\MyLambdaExamples.java<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<pre start-line=\"64\">\r\n\/\/ \u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269\r\nSystem.out.println(\"\\n<-- \u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269 -->\");\r\nOptional<Sale> mostCostlySale;\r\nComparator<Sale> byCost = comparing((ToDoubleFunction<Sale>) Sale::getCost)\r\n        .reverseOrder();\r\nmostCostlySale = sales.sorted(byCost)\r\n        .findFirst();\r\nif (mostCostlySale.isPresent()) {\r\n    System.out.println((int)mostCostlySale.get().getCost() + \"\u5186   \"\r\n            + mostCostlySale.get().wristwatch.getBrand()\r\n            + \"   \" + mostCostlySale.get().wristwatch.getModel());\r\n}\r\n\r\n<\/pre>\n<p>\u307e\u305f\u3001Optional , ToDoubleFunction , findFirst() \u304c\u51fa\u3066\u304d\u307e\u3057\u305f\u306d\u3002<\/p>\n<p>ToDoubleFunction \u306f ToIntFunction \u306e double \u30d0\u30fc\u30b8\u30e7\u30f3\u306e\u3088\u3046\u3067\u3059\u3002<\/p>\n<p>Sale \u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u58f2\u308a\u5024\u304c\u9ad8\u4fa1\u306a\u9806\u306b\u30bd\u30fc\u30c8\u3057\u3066\u3001\u3055\u3089\u306b\u305d\u308c\u3092 sales \u30b9\u30c8\u30ea\u30fc\u30e0\u306e\u30bd\u30fc\u30c8\u306e\u5f15\u6570\u306b\u3001<\/p>\n<p>\u305d\u3057\u3066\u3001findFirst() \u30e1\u30bd\u30c3\u30c9\u306b\u3088\u3063\u3066\u6700\u521d\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308b\u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269\u3092 Optional&lt;Sale&gt; mostCostlySale \u306b\u4ee3\u5165\u3002<\/p>\n<p>71 \u884c\u76ee\u3067 isPresent() \u30e1\u30bd\u30c3\u30c9\u3067\u76ee\u7684\u306e\u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269\u306e\u8981\u7d20\u304c\u3042\u308b\u304b\u78ba\u8a8d\u3057\u3066\u8868\u793a\u3055\u305b\u3066\u308b\u3088\u3046\u3067\u3059\u3002<\/p>\n<p>\u7121\u3044\u5834\u5408\u306e\u51e6\u7406\u306f\u7701\u7565\u3057\u3066\u307e\u3059\u3002<\/p>\n<p>\u6628\u65e5\u3068\u4eca\u65e5\u3067 Optional \u3068 ToIntFunction , ToDoubleFunction , findFirst() , isPresent() \u306e\u4f7f\u3044\u3069\u3053\u308d\u3092\u5c11\u3057\u3060\u3051\u7406\u89e3\u3067\u304d\u305f\u3088\u3046\u306a\u6c17\u304c\u3057\u307e\u3059\u3002<\/p>\n<p>\u305d\u308c\u3067\u306f\u6c17\u306b\u306a\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>&lt;&#8211; \u6700\u3082\u9ad8\u4fa1\u306a\u58f2\u308a\u7269 &#8211;&gt;<br \/>1000000\u5186&nbsp;&nbsp; \u30c6\u30a3\u30d5\u30a1\u30cb\u30fc&nbsp;&nbsp; \u30dd\u30fc\u30bb\u30ea\u30f3<\/p>\n<p>\u671f\u5f85\u901a\u308a\u306e\u7d50\u679c\u304c\u5f97\u3089\u308c\u3066\u307e\u3059\u3002<\/p>\n<p>\u4fbf\u5229\u3067\u3059\u306d\uff01<\/p>\n<p>\u3067\u3082\u3001\u3053\u306e\u300cJDK8 Lambda \u305d\u306e\u4ed6\u3044\u308d\u3044\u308d \u306a\u3093\u3067\u3082\u3044\u3044\u304b\u3089\u52d5\u304b\u3057\u3066\u307f\u308b\u300d\u30b7\u30ea\u30fc\u30ba\u306f\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u4e0a\u3067\u5f97\u305f\u60c5\u5831\u3092\u5143\u306b\u305d\u308c\u3092\u5c11\u3057\u5909\u66f4\u3057\u3066\u3044\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n<p>\u60b2\u3057\u3044\u3053\u3068\u306b\u305d\u306e\u60c5\u5831\u6e90\u306f\u82f1\u8a9e\u306a\u306e\u3067\u8a73\u3057\u3044\u5185\u5bb9\u306f\u308f\u304b\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>\u3088\u3063\u3066\u79c1\u306e\u63a8\u6e2c\u3067\u89e3\u91c8\u3055\u308c\u305f\u5185\u5bb9\u3068\u306a\u3063\u3066\u307e\u3059\u306e\u3067\u9593\u9055\u3044\u304c\u3042\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n<p>Java8 \u3082\u307e\u3060 build83 \u3092\u4f7f\u7528\u3057\u3066\u3044\u307e\u3059\u306e\u3067 API \u306e\u5909\u66f4\u306b\u3088\u308a\u8a18\u8ff0\u65b9\u6cd5\u304c\u5909\u308f\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u3002<\/p>\n<p>\u65e9\u304f\u6b63\u5f0f\u30ea\u30ea\u30fc\u30b9\u3055\u308c\u3066\u65e5\u672c\u8a9e\u3067\u3053\u306e\u8d85\u4fbf\u5229\u3067\u7d20\u6575\u306a\u65b0\u6a5f\u80fd\u3092\u52c9\u5f37\u3057\u305f\u3044\u4eca\u65e5\u3053\u306e\u9803\u3067\u3059\u3002<\/p>\n<div id=\"scid:0767317B-992E-4b12-91E0-4F059A8CECA8:7a57a26a-4619-451e-9b90-6089e9b67797\" class=\"wlWriterEditableSmartContent\" style=\"float: none; 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Optional mostCostlySale; Comparator byCost = comparing((ToDoubleFunction) Sale::getCost) .reverseOrder(); mostCostlySale = sales.sorted(byCost) .\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[17],"class_list":["post-689","post","type-post","status-publish","format-standard","hentry","category-java","tag-java"],"_links":{"self":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/689","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=689"}],"version-history":[{"count":2,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/689\/revisions"}],"predecessor-version":[{"id":788,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/689\/revisions\/788"}],"wp:attachment":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=689"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=689"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=689"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}