Collectors (java.util.stream API仕様 b128 éžå…¬å¼ç¿»è¨³)è¦ç´ をコレクションã«ç´¯ç©ã™ã‚‹ã€æ§˜ã€…ãªæ¡ä»¶ã«ã‚ˆã£ã¦è¦ç´ ã‚’è¦ç´„ã™ã‚‹ãªã©ã€æ§˜ã€…ãªä¾¿åˆ©ãªç°¡ç´„処ç†ã‚’実装ã—ãŸCollectorã®å®Ÿè£…。 次ã®ã‚³ãƒ¼ãƒ‰ã¯äºˆã‚用æ„ã•ã‚ŒãŸã‚³ãƒ¬ã‚¯ã‚¿ã‚’使ã£ã¦ã‚ˆãã‚ã‚‹å¯å¤‰ç°¡ç´„作æ¥ã‚’ã™ã‚‹ä¾‹ã§ã‚る。 // åå‰ã‚’Listã«ç´¯ç©ã™ã‚‹ List<String> list = people.stream().map(Person::getName).collect(Collectors.toList()); // åå‰ã‚’TreeSetã«ç´¯ç©ã™ã‚‹ Set<String> set = people.stream().map(Person::getName).collect(Collectors.toCollection(TreeSet::new)); // è¦ç´ ã‚’æ–‡å—列ã«å¤‰æ›ã—ã€ã‚«ãƒ³ãƒžã§åŒºåˆ‡ã£ã¦é€£çµã™ã‚‹ String joined = things.stream() .map(Object::
Shin Tanimoto / CERO-METAL on Twitter: "勉強é‡ãŒæ¸›ã£ã¦ã¯ã„ã‚‹ã‘ã©ã€ã‚³ãƒ¼ãƒ‰ãƒ¬ãƒ“ューã®èƒ½åŠ›ã¯é«˜ã„「30代åŠã°ä»¥ä¸Šã€ã®Javaエンジニアã®ã“ã‚Œã‹ã‚‰ãŒãƒ¤ãƒã„。勉強ã—ãªã„ã‹ã‚‰Java8ã®Stream APIãŒèªã‚ãšç½®ã„ã¦ã‘ã¼ã‚Šã€ã¨è¦‹ã›ã‹ã‘ã¦ã€Œèªã¿ã«ãã„ã‹ã‚‰Stream APIç¦æ¢ã€ã¨ã„ã†ä¸€å¤§è€å®³å‹¢åŠ›ã«å…¥ã‚Šã‹ããªã„。ヤãƒã„。"
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Java8ã«ãŠã‘ã‚‹indyã¨Lambdaã®çµ¶å¦™ãªé–¢ä¿‚ã€ã‚‚ã—ãã¯SAMタイプを継承ã™ã‚‹å†…部クラスã®.classファイルã¯ã©ã“ã¸è¡Œã£ãŸã®? - uehaj's blog
関数を扱ãˆã‚‹ã ã‘ã§ã¯ã€ãƒ¢ãƒŠãƒ‰ã‚’表ç¾ã™ã‚‹ã«ã¯ä¸å分éŽãŽã‚‹ - xuwei-k's blog
Java8ã®OptionalãŒãƒ¢ãƒŠãƒ‰ã«ãªã£ãŸã‚ˆï¼ - ãã—ã ã®Hatena
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