[B! java8] bobbyjam99ã®ãƒ–ãƒƒã‚¯ãƒžãƒ¼ã‚¯

bobbyjam99 id:bobbyjam99

java8ã«é–¢ã™ã‚‹bobbyjam99ã®ãƒ–ãƒƒã‚¯ãƒžãƒ¼ã‚¯ (48)

${{author_name}}$

{{{comment_expanded}}}

{{label}}

{{#is_bookmark}}ãƒªã‚¹ãƒˆ{{/is_bookmark}}{{^is_bookmark}}ãƒªãƒ³ã‚¯{{/is_bookmark}}

${{author_name}}$
{{author_name}}{{created}}
{{ #comment }}{{ comment }}{{ /comment }}
- {{ label }}

${{author_name}}$

{{{comment_expanded}}}

{{label}}

{{#is_bookmark}}ãƒªã‚¹ãƒˆ{{/is_bookmark}}{{^is_bookmark}}ãƒªãƒ³ã‚¯{{/is_bookmark}}

Stream APIã®æ¼”ç¿’ã€æ§˜ã€…ãªå‡¦ç†ã§ã‚¹ãƒˆãƒªãƒ¼ãƒ ã‚’ä½¿ã£ã¦ã¿ã‚‹
å‰å›žã€å‰ã€…å›žã¨2å›žã«æ¸¡ã£ã¦ã€ã‚¹ãƒˆãƒªãƒ¼ãƒ ã®åŸºæœ¬çš„ãªä½¿ã„æ–¹ã«ã¤ã„ã¦èª¬æ˜Žã—ã¦ãã¾ã—ãŸã€‚ ã¨ã¯ã„ã†ã‚‚ã®ã®ã€ã„ã–ã‚¹ãƒˆãƒªãƒ¼ãƒ ã‚’ä½¿ãŠã†ã¨ã—ã¦ã‚‚ã€ãªã‹ãªã‹ã™ã‚“ãªã‚Šã¨ã¯ã„ã‹ãªã„ã®ã‚‚ä»•æ–¹ãŒãªã„ã¨ã“ã‚ã§ã™ã€‚ä»Šã¾ã§ã®Javaã®ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã‚¹ã‚¿ã‚¤ãƒ«ã‹ã‚‰ã™ã‚‹ã¨ã€ã‚¹ãƒˆãƒªãƒ¼ãƒ ã®ã‚¹ã‚¿ã‚¤ãƒ«ã¯å¤§ããç•°ãªã‚Šã¾ã™ã€‚ç‰¹ã«é–¢æ•°ã‚’ç”¨ã„ã¦å‡¦ç†ã‚’æŒ‡å®šã—ã¦ã„ãæ–¹æ³•ã¯ã€ä»Šã¾ã§ã®Javaã§ã¯ã‚ã¾ã‚Šã‚ã‚Šã¾ã›ã‚“ã§ã—ãŸã€‚ ã“ã®ã‚¹ã‚¿ã‚¤ãƒ«ã¯æœ¬é€£è¼‰ã®ã€ŒJava SE 8ã®ãƒ©ãƒ ãƒ€å¼ã¯ã©ã†ã‚„ã£ã¦æ´»ç”¨ã™ã‚‹ã‹ã€ã§ç´¹ä»‹ã—ãŸã€é«˜éšŽé–¢æ•°ã‚’ç”¨ã„ãŸé–¢å¿ƒã®åˆ†é›¢ã«ä»–ãªã‚Šã¾ã›ã‚“ã€‚ ãã“ã§ã€ä»Šå›žã¯æ§˜ã€…ãªå‡¦ç†ã‚’ã‚¹ãƒˆãƒªãƒ¼ãƒ ã§è¡Œã†ã“ã¨ã«ã‚ˆã‚Šã€ã‚¹ãƒˆãƒªãƒ¼ãƒ ã‚’ä½¿ã†ä¸Šã§ã®è€ƒãˆæ–¹ã‚’ç´¹ä»‹ã—ã¦ã„ãã¾ã™ã€‚ æ¡ä»¶ã«åˆè‡´ã™ã‚‹ã‚‚ã®ã«å¯¾ã—ã¦å‡¦ç†ã‚’è¡Œã† æ‹¡å¼µforæ–‡ã‚’ä½¿ç”¨ã—ã¦ãƒªã‚¹ãƒˆ1ã®ã‚ˆã†ãªå‡¦ç†ã‚’æ›¸ãã“ã¨ã¯ã‚ã‚Šã¾ã›ã‚“ã‹ã€‚ ãƒªã‚¹ãƒˆ1â—æ¡ä»¶ã«åˆè‡´ã—ãŸè¦ç´ ã«å¯¾ã—å‡¦ç†ã‚’è¡Œã† List<String> elements =
bobbyjam99 2016/02/25
java

java8

lambda
ãƒªãƒ³ã‚¯
OptionalãŒSerializableã§ã¯ãªã„è©±ã¨ä½¿ã„æ–¹ã¾ã¨ã‚ - ãã—ã ã®Hatena
Optionalã¯æ„å›³çš„ã«Serializableã§ã¯ãªããªã£ã¦ã¾ã™ãã€‚ ã§ãã®æ„å›³ã¨ã—ã¦ã¯ã€ä¸€æ—¦Serializableã«ã—ã¦å‡ºåŠ›å½¢å¼ã‚’æ±ºã‚ã¦ã—ã¾ã†ã¨ã€ä»Šå¾Œãšã£ã¨ãã®å‡ºåŠ›å½¢å¼ã‚’ç¶æŒã—ãªã„ã¨ã„ã‘ãªã„ã“ã¨ã«ãªã‚‹ã®ã§ã€ãã®ãƒ¡ãƒ³ãƒ†ãƒŠãƒ³ã‚¹ã‚³ã‚¹ãƒˆã‚’å«Œã£ãŸã¨ã„ã†ã®ãŒã‚ã‚‹ã‚ˆã†ã§ã™ã€‚ ã“ã®ãƒ¡ãƒ³ãƒ†ãƒŠãƒ³ã‚¹ã‚³ã‚¹ãƒˆã®ä¸ã«ã¯ã€ä»•æ§˜ãŒå¤‰ãˆã‚Œãªããªã‚‹ã€ã¨ã„ã†ã‚³ã‚¹ãƒˆã‚‚å«ã¿ã¾ã™ã€‚ ãªã®ã§ã€ã‚·ãƒªã‚¢ãƒ©ã‚¤ã‚ºã—ãŸã„å ´åˆã«ã¯ã€ãƒ•ã‚£ãƒ¼ãƒ«ãƒ‰ã¯nullã‚’æŒã¤ã‚ˆã†ã«ã—ã¦ã€getterã§Optionalã«å¤‰æ›ã™ã‚‹ã¨ã„ã†ã“ã¨ã«ãªã‚‹ã¨æ€ã„ã¾ã™ã€‚ åŸºæœ¬çš„ã«Optionalã¯ã€Optional-returnã‚¤ãƒ‡ã‚£ã‚ªãƒ ã‚’ã‚µãƒãƒ¼ãƒˆã™ã‚‹ã‚‚ã®ä»¥ä¸Šã§ã¯ãªã„ã€ã¨ã„ã†ã“ã¨ã‚’Brian goetzã•ã‚“ã‚‚æ›¸ã„ã¦ã„ã¾ã™ã€‚ Shouldn't Optional be Serializable? ãã“ã§ã€Optionalã®ä½¿ã„æ–¹ã¨ã—ã¦ã¯ã€åŸºæœ¬çš„ã«ãƒ¡ã‚½ãƒƒãƒ‰ã®æˆ»ã‚Šå€¤ã¨ã—ã¦ã ã‘ã€
bobbyjam99 2015/09/01
java

java8
ãƒªãƒ³ã‚¯
ã‚¹ãƒ†ãƒƒãƒ—ãƒ»ãƒã‚¤ãƒ»ã‚¹ãƒ†ãƒƒãƒ—ã§å¦ã¶ãƒ©ãƒ ãƒ€å¼ãƒ»Stream apiå…¥é–€ #jjug ccc #ccc h2
Spring Securityã‚’è§¦ã£ãŸã“ã¨ãŒã‚ã‚‹ã‘ã©ã€è£ã§ä½•ãŒèµ·ã“ã£ã¦ã„ã‚‹ã‹åˆ†ã‹ã‚‰ãšã€ãƒ¢ãƒ¤ãƒ¢ãƒ¤ã—ã¦ã‚‹æ–¹ã«ãŠå‹§ã‚ã®è³‡æ–™ã§ã™ã€‚ Spring Securityã®ã‚ãƒ¼ã¨ãªã‚‹ã€ŒSecurity Filter Chainã€ã¨ã€ŒSecurity Contextã€ã«ã¤ã„ã¦ã˜ã£ãã‚Šèª¬æ˜Žã—ã¦ã„ã¾ã™ã€‚ æœ¬è³‡æ–™ã‚’èªã‚“ã§ã„ãŸã ã‘ã‚Œã°ã€Spring Securityã®ãƒ‡ãƒãƒƒã‚°ã‚„ã‚«ã‚¹ã‚¿ãƒžã‚¤ã‚ºãŒã—æ˜“ããªã‚‹ã¯ãšã§ã™ã€‚ â€»èªè€…ã®æƒ³å®šã¨ã—ã¦Spring Securityã«è§¦ã£ãŸã“ã¨ãŒã‚ã‚‹æ–¹ã‚’æƒ³å®šã—ã¦ã„ã¾ã™ã€‚å…¨ãã®åˆå¿ƒè€…ã®æ–¹ã¯ã€ç°¡å˜ãªèªè¨¼ãƒ»èªå¯ã‚’äº‹å‰ã«å‹•ã‹ã—ã¦ã¿ã‚‹ã“ã¨ã‚’ãŠå‹§ã‚ã—ã¾ã™ã€‚
bobbyjam99 2015/06/19
java8

stream

lambda

java
ãƒªãƒ³ã‚¯
ãƒ©ãƒ ãƒ€å¼ã¨ã‚¹ãƒˆãƒªãƒ¼ãƒ APIã§Javaãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã¯ã“ã“ã¾ã§ã‚·ãƒ³ãƒ—ãƒ«ã«ãªã‚‹ï¼--Java SE 8ã«ä»Šã™ãç§»è¡Œã™ã¹ãç†ç”± - builder by ZDNet Japan
ã€Œå¤§ããé€²åŒ–ã—ãŸJava SE 8ã¯ä¼æ¥ã«å¤šãã®ãƒ¡ãƒªãƒƒãƒˆã‚’ã‚‚ãŸã‚‰ã™ã€‚ãƒ—ãƒã‚¸ã‚§ã‚¯ãƒˆãƒ»ãƒžãƒã‚¸ãƒ£ãƒ¼ã‚„ã‚¢ãƒ¼ã‚ãƒ†ã‚¯ãƒˆã‚‚ã€ä»Šã™ãç§»è¡Œã«å–ã‚ŠæŽ›ã‹ã‚‹ã¹ãã€ã¨è¨´ãˆã‚‹Javaã‚¨ãƒãƒ³ã‚¸ã‚§ãƒªã‚¹ãƒˆã®å¯ºç”°ä½³å¤®æ°ã€‚ãƒ©ãƒ ãƒ€å¼ã¨ã‚¹ãƒˆãƒªãƒ¼ãƒ APIã‚’ä¾‹ã«ã¨ã‚Šã€Java SE 8ã«ã‚ˆã‚‹ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã®ç‰¹å¾´ã¨åˆ©ç‚¹ã‚’èªžã£ãŸã€‚ 2014å¹´3æœˆã«ãƒªãƒªãƒ¼ã‚¹ã•ã‚ŒãŸã€ŒJava SE 8ã€ã®å¤§ããªå¤‰æ›´ç‚¹ã®1ã¤ã¯ã€æ–°ãŸãªè¨€èªžæ©Ÿèƒ½ã¨ã—ã¦ã€Œãƒ©ãƒ ãƒ€å¼ï¼ˆLambda Expressionsï¼‰ã€ãŒå°Žå…¥ã•ã‚ŒãŸã“ã¨ã ã€‚åŒæ©Ÿèƒ½ã‚’ä½¿ã†ã“ã¨ã§ã€é–‹ç™ºè€…ã¯å¾“æ¥ã‚ˆã‚Šã‚‚åŠ¹çŽ‡çš„ã«ãƒ—ãƒã‚°ãƒ©ãƒ ã‚’æ›¸ã‘ã‚‹ã‚ˆã†ã«ãªã‚‹ã€‚ã¾ãŸã€ä½µã›ã¦å°Žå…¥ã•ã‚ŒãŸã€Œã‚¹ãƒˆãƒªãƒ¼ãƒ APIï¼ˆStream APIï¼‰ã€ã‚’ä½¿ç”¨ã™ã‚‹ã“ã¨ã§ä¸¦åˆ—å‡¦ç†ã®å®Ÿè£…ãŒå®¹æ˜“ã¨ãªã‚Šã€ãƒžãƒ«ãƒã‚³ã‚¢ãƒ»ãƒ—ãƒã‚»ãƒƒã‚µã®èƒ½åŠ›ã‚’ç”Ÿã‹ã—ãŸãƒã‚¤ãƒ‘ãƒ•ã‚©ãƒ¼ãƒžãƒ³ã‚¹ãªã‚¢ãƒ—ãƒªã‚±ãƒ¼ã‚·ãƒ§ãƒ³ã‚’è¿…é€Ÿã«ä½œã‚Œã‚‹ã‚ˆã†ã«ãªã‚‹ã€‚ æ—¥æœ¬ã‚ªãƒ©ã‚¯ãƒ«ã®Javaã‚¨ãƒãƒ³ã‚¸ã‚§ãƒªã‚¹ãƒˆ å¯ºç”°ä½³å¤®æ°ã¯ã€ä¼æ¥ã®
bobbyjam99 2015/06/18
Actorã®ã‚µãƒ³ãƒ—ãƒ«ãŒã©ã†ã—ã¦ã“ã†ãªã£ãŸã®ã‹çŸ¥ã‚ŠãŸã„

java8

java

lambda
ãƒªãƒ³ã‚¯
Javaã§1è¡Œãšã¤ãƒ†ã‚ã‚¹ãƒˆãƒ‡ãƒ¼ã‚¿ã‚’èªã¿è¾¼ã‚€ã‚¤ãƒ‡ã‚£ã‚ªãƒ ã®å¤‰é· - argius note
ãƒ†ã‚ã‚¹ãƒˆãƒ‡ãƒ¼ã‚¿ã‚’èªã¿è¾¼ã‚€å ´åˆã€è¨€èªžã«ã‹ã‹ã‚ã‚‰ãš1è¡Œãšã¤èªã¿è¾¼ã‚“ã§å‡¦ç†ã—ã¾ã™ã€‚ã“ã“ã§ã¯ã“ã®ã‚¤ãƒ‡ã‚£ã‚ªãƒ ã‚’"read-lines"ã¨å‘¼ã¶ã“ã¨ã«ã—ã¾ã™ã€‚ ã‚¹ã‚¯ãƒªãƒ—ãƒˆè¨€èªžãªã‚“ã‹ã ã¨å¤§æŠµã€æœ€åˆã‹ã‚‰foreachã§æ¸ˆã‚“ã§ã—ã¾ã£ã¦ã„ãŸã‚Šã—ã¾ã™ãŒã€åˆæœŸã®Javaã§ã¯ã¡ã‚‡ã£ã¨é¢å€’ãªæ‰‹é †ãŒå¿…è¦ã§ã—ãŸã€‚ æ–°ã—ã„ãƒãƒ¼ã‚¸ãƒ§ãƒ³ã§ã¯ã ã„ã¶ç°¡å˜ç°¡æ½”ã«æ›¸ã‘ã‚‹ã‚ˆã†ã«ãªã‚Šã¾ã—ãŸãŒã€ä»Šåº¦ã¯ãŸãã•ã‚“ã‚ã‚Šã™ãŽã¦ã€ã©ã‚ŒãŒãªã‚“ãªã®ã‹ãŒè‰¯ãã‚ã‹ã‚‰ãªããªã£ã¦ã„ã¾ã™ï¼ˆå¤§è¢ˆè£Ÿï¼‰ã€‚ ãã“ã§ä»Šå›žã¯ã€"read-lines"ã®å¤‰é·ã«ã¤ã„ã¦ã¾ã¨ã‚ã¦ã¿ã¾ã—ãŸã€‚ æœ€è¿‘Javaã‚’å§‹ã‚ãŸæ–¹ãŒãƒãƒ¼ã‚¸ãƒ§ãƒ³ãŒå¤ã„æ™‚ã«æ›¸ã‹ã‚ŒãŸã‚½ãƒ¼ã‚¹ã‚³ãƒ¼ãƒ‰ã‚’èªã‚€ã¨ãã«å½¹ã«ç«‹ã¤...ã‹ã‚‚çŸ¥ã‚Œã¾ã›ã‚“ã€‚ ç›®æ¬¡ åŸºæœ¬ BufferedReader ï¼ˆJava1.1ï½žï¼‰ Scannerã¨æ‹¡å¼µforæ–‡ ï¼ˆJava5ï½žï¼‰ java.nio.file.Filesã¨try-with-resourcesï¼ˆJ
bobbyjam99 2015/06/07
java

java8
ãƒªãƒ³ã‚¯
Javaã®Streamã§å¦ã¶é…å»¶å‡¦ç†å®Ÿè£…ãƒ‘ã‚¿ãƒ¼ãƒ³
6. Streamã®å¾©ç¿’ repo.findAllUsers().stream() .filter(User::isMen) .filter(u -> u.getAge() >= 27) .filter(u -> u.getAge() <= 35) .map(User::getHobbies) .flatMap(List::stream) .collect(groupingBy( Hobby::getGenre, counting())); ã‚½ãƒ¼ã‚¹ ã‚¹ãƒˆãƒªãƒ¼ãƒ ãƒ‘ã‚¤ãƒ—ãƒ©ã‚¤ãƒ³ çµ‚ç«¯æ“ä½œ 7. Streamã®ç–‘å• repo.findAllUsers().stream() .filter(User::isMen) .filter(u -> u.getAge() >= 27) .filter(u -> u.getAge() <= 35) .map(User::getHobbies) .flatMap
bobbyjam99 2015/06/02
java8

stream

java
ãƒªãƒ³ã‚¯
ç°¡æ½”ãªJavaã‚³ãƒ¼ãƒ‰
Spring Bootã«ã‚ˆã‚‹APIãƒãƒƒã‚¯ã‚¨ãƒ³ãƒ‰æ§‹ç¯‰å®Ÿè·µã‚¬ã‚¤ãƒ‰ ç¬¬2ç‰ˆ ä½•åƒäººã‚‚ã®é–‹ç™ºè€…ãŒã€InfoQã®ãƒŸãƒ‹ãƒ–ãƒƒã‚¯ã€ŒPractical Guide to Building an API Back End with Spring Bootã€ã‹ã‚‰ã€Spring Bootã‚’ä½¿ã£ãŸREST APIæ§‹ç¯‰ã®åŸºç¤Žã‚’å¦ã‚“ã ã€‚ã“ã®æœ¬ã§ã¯ã€å‡ºç‰ˆæ™‚ã«æ–°ã—ããƒªãƒªãƒ¼ã‚¹ã•ã‚ŒãŸãƒãƒ¼ã‚¸ãƒ§ãƒ³ã§ã‚ã‚‹ Spring Boot 2 ã‚’ä½¿ç”¨ã—ã¦ã„ã‚‹ã€‚ã—ã‹ã—ã€Spring Boot3ãŒæœ€è¿‘ãƒªãƒªãƒ¼ã‚¹ã•ã‚Œã€é‡è¦ãªå¤‰...
bobbyjam99 2015/05/25
java

java8
ãƒªãƒ³ã‚¯
15 Must Read Java 8 Tutorials
Java 8 was released last month and is just chock-full of new features and behind-the-scenes optimizations. The internet has been doing quite a good job covering all these new additions â€“ both the good and the bad. I thought itâ€™d be good to do a round-up of what we think are some of the best tutorials out there, to help you get you quickly up-to-speed on whatâ€™s new and what you need to know. Java 8
bobbyjam99 2015/05/21
java

java8
ãƒªãƒ³ã‚¯
Groovyã®ã‚¯ãƒãƒ¼ã‚¸ãƒ£ã¨Java8ã®lambdaå¼ã®é•ã„ã«ã¤ã„ã¦ - uehaj's blog
ã“ã®ä¸¡è€…ã¯ã€ä¼¼ã¦ã„ã‚‹ã‚ˆã†ã§ã„ã¦ã€åŸºæœ¬çš„ã«ã¯åˆ¥ãƒ¢ãƒŽã§ã™ã€‚è¡¨ã«ã—ã¦ã¿ã¾ã™ã€‚ Groovyã®ã‚¯ãƒãƒ¼ã‚¸ãƒ£ java8ã®lambdaå¼ å°Žå…¥æ™‚æœŸ 2003å¹´ 2014å¹´03æœˆ ãƒãƒ¼ã‚«ãƒ«å¤‰æ•°ã¸ã®ã‚¢ã‚¯ã‚»ã‚¹ èªã¿æ›¸ãå¯èƒ½ å®Ÿè³ªçš„ã«final(å¤‰æ•°ãã®ã‚‚ã®ã«å¯¾ã—ã¦ã¯èªã¿è¾¼ã¿ã®ã¿) å®Ÿè£…æ–¹æ³• Closureåž‹ã®ã‚¤ãƒ³ã‚¹ã‚¿ãƒ³ã‚¹ MethodHandle, invokeDynamic.. åž‹æŽ¨è«–ã®æ ¹æ‹ Closure<T>ã®Tã§è¿”ã‚Šå€¤ã€@ClosureParamsã§å¼•æ•° FunctionalInterface(SAMåž‹) è¨˜æ³• { å¼•æ•° -> æœ¬ä½“ } { æœ¬ä½“ } {-> æœ¬ä½“ } (å¼•æ•°) -> { æœ¬ä½“ } (å¼•æ•°) -> å¼ () -> { æœ¬ä½“ } æš—é»™ã®å‹•çš„ãªthis delegateã«ã‚ˆã‚Šå®Ÿç¾ - æ€§èƒ½ ãƒãƒ¼ã‚«ãƒ«å¤‰æ•°ã‚’enclosingã™ã‚‹ãŸã‚é–“æŽ¥å‚ç…§ã«ã™ã‚‹ãŸã‚ã®ã‚ªãƒ¼ãƒãƒ¼ãƒ˜ãƒƒãƒ‰ã‚ã‚Š æ€§èƒ½ä¸Šã®ã‚ªãƒ¼ãƒãƒ¼ãƒ˜
bobbyjam99 2015/04/20
groovy

java8

lambda
ãƒªãƒ³ã‚¯
JDK 8 JVM Improvements - C2-JavaDay-304328.pdf
bobbyjam99 2015/03/15
jvm

java

java8
ãƒªãƒ³ã‚¯
streamã¨parallelStreamã«ã¤ã„ã¦ã®è€ƒå¯Ÿ
Java8ã§å°Žå…¥ã•ã‚Œã‚‹streamã¨parallelStreamã€‚ã©ã†ã„ã£ãŸå ´é¢ã§ã€ã©ã¡ã‚‰ã‚’ä½¿ã†ã®ãŒãƒ™ã‚¿ãƒ¼ãªã®ã‹ï¼Ÿã«ã¤ã„ã¦ã®ã¾ã¨ã‚
bobbyjam99 2015/03/11
java

java8
ãƒªãƒ³ã‚¯
Java 8 Date Time - 20 Examples of LocalDate, LocalTime, LocalDateTime
Learn Java, Programming, Spring, Hibernate throw tutorials, examples, and interview questions Along with lambda expressions, streams, and several minor goodies, Java 8 has also introduced brand new Date and Time API, and in this tutorial, we will learn how to use Java 8 Date Time API with simple how-to-do task examples. Java's handling of Date, Calendar, and Time is long been criticized by the com
bobbyjam99 2015/03/10
java

java8
ãƒªãƒ³ã‚¯
JDays Lviv 2014: Java8 vs Scala: Difference points & innovation stream
3. SCALA JAVA8 public class Person { private String firstName; private String lastName; String getFirstName() { return firstName; } void setFirstName(String v) { firstName = v; } â€¦â€¦â€¦â€¦â€¦â€¦â€¦. int hashCode() { if (firstName==null) { if (secondName==null) { return 0; } else { return secondName.hashCode(); } } else{ if (secondName==null) { } } } boolean equals() { â€¦. } } case class Person ( firstName: St
bobbyjam99 2015/01/21
java8

java

scala
ãƒªãƒ³ã‚¯
Java 8ã¨Scala â€ã‚¢ãƒ—ãƒãƒ¼ãƒã®é•ã„ã¨ç›¸äº’ã‚¤ãƒŽãƒ™ãƒ¼ã‚·ãƒ§ãƒ³ | POSTD
Scalaã¨Java 8ã«é–¢ã™ã‚‹ ãƒ—ãƒ¬ã‚¼ãƒ³ãƒ†ãƒ¼ã‚·ãƒ§ãƒ³ ãŒã€ä»–ã®ä¼¼ãŸå†…å®¹ã®ã‚‚ã®ã‚ˆã‚Šã‚‚å¤šããƒªãƒ„ã‚¤ãƒ¼ãƒˆã•ã‚Œã€å¤§å¤‰ã†ã‚Œã—ãæ€ã„ã¾ã™ã€‚ã ã‹ã‚‰ã€ã“ã†ã—ã¦çš†ã•ã‚“ã«ãƒ–ãƒã‚°ã§ã‚‚æ›¸ã„ã¦ãŠä¼ãˆã™ã‚‹ã“ã¨ã«ã—ã¾ã—ãŸã€‚Scalaã¨Javaã¨ã®é•ã„ã¨ã€ãã‚Œãžã‚Œã®é‡è¦æ€§ã«ã¤ã„ã¦ãŠè©±ã—ã—ã¾ã™ã€‚ä¸¡è€…ã¯ç›¸äº’ã«ã‚¤ãƒŽãƒ™ãƒ¼ã‚·ãƒ§ãƒ³ã—ã¦ã„ã¾ã™ã€‚è¨€èªžé–“ã§ãŠäº’ã„ã«å–ã‚Šå…¥ã‚Œã¦ã„ã¾ã™ã€‚ã§ã¯ã€JavaãŒä½¿ãˆã‚‹å ´åˆã§ã‚ã£ã¦ã‚‚ã€Scalaã‚’å¦ã¶å¿…è¦ãŒã‚ã‚‹ã®ã§ã—ã‚‡ã†ã‹ï¼Ÿã€€ã‚‚ã¡ã‚ã‚“ã§ã™ã€‚ã‚ˆã‚Šå¤šãã®è¨€èªžã‚’çŸ¥ã‚Œã°çŸ¥ã‚‹ã»ã©ã€ã‚ãªãŸã¯ã•ã‚‰ã«ãƒ—ãƒãƒ•ã‚§ãƒƒã‚·ãƒ§ãƒŠãƒ«ã«ãªã£ã¦ã„ãã¾ã™ã€‚ ã‚‚ã—ã€Scala ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã«Scalaã¨Javaã¨ã®åŸºæœ¬çš„ãªé•ã„ã«ã¤ã„ã¦å°‹ããŸã¨ã—ã¦ã‚‚ã€ãŠãã‚‰ããã®äººã¯ãƒ©ãƒ ãƒ€é–¢æ•°ã¨ãƒˆãƒ¬ã‚¤ãƒˆã«é–¢ã™ã‚‹é•ã„ã‚’å…¨ã¦è¨€ã†ã“ã¨ã¯ãªã„ã§ã—ã‚‡ã†ã€‚ä»£ã‚ã‚Šã«æ¬¡ã®ã‚ˆã†ãªä¾‹ã‚’å‡ºã™ã¯ãšã§ã™ã€‚ public class Person { private String firstN
bobbyjam99 2015/01/21
java

java8

scala
ãƒªãƒ³ã‚¯
ãƒ©ãƒ ãƒ€å¼ã§Strategyãƒ‘ã‚¿ãƒ¼ãƒ³ã§å®Ÿè£…ã•ã‚ŒãŸã‚³ãƒ¼ãƒ‰ã‚’ã‚·ãƒ³ãƒ—ãƒ«ã«ã™ã‚‹ ï½ž ãã“ã‹ã‚‰è¦‹ãˆã¦ãã‚‹ã‚¹ãƒˆãƒ©ãƒ†ã‚¸ã‚ªãƒ–ã‚¸ã‚§ã‚¯ãƒˆã®æœ¬è³ª
CodeZineç·¨é›†éƒ¨ã§ã¯ã€ç¾å ´ã§æ´»èºã™ã‚‹ãƒ‡ãƒ™ãƒãƒƒãƒ‘ãƒ¼ã‚’ã‚¹ã‚¿ãƒ¼ã«ã™ã‚‹ãŸã‚ã®ã‚«ãƒ³ãƒ•ã‚¡ãƒ¬ãƒ³ã‚¹ã€ŒDevelopers Summitã€ã‚„ã€ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã®ç”Ÿãã–ã¾ã‚’ãƒ–ãƒ¼ã‚¹ãƒˆã™ã‚‹ãŸã‚ã®ã‚¤ãƒ™ãƒ³ãƒˆã€ŒDevelopers Boostã€ãªã©ã€ã•ã¾ã–ã¾ãªã‚«ãƒ³ãƒ•ã‚¡ãƒ¬ãƒ³ã‚¹ã‚’ä¼ç”»ãƒ»é‹å–¶ã—ã¦ã„ã¾ã™ã€‚
bobbyjam99 2015/01/21
java

java8

lambda
ãƒªãƒ³ã‚¯
åƒ•ã®Optional<>ã®ä½¿ã„æ–¹ãŒã‚«ãƒƒã‚³ãƒ¯ãƒ«ã‚¤ã€‚ - è°·æœ¬ å¿ƒ in ã›ã‚éƒ¨å±‹
æ˜¨æ—¥ã€Spring MVCã®Optionã®ä½¿ã„æ–¹ãŒã‚«ãƒƒã‚³ã‚¤ã‚¤ã¨ã„ã†è©±ã§ã€ã“ã‚“ãªã‚³ãƒ¼ãƒ‰ã‚’æ›¸ãã¾ã—ãŸã€‚ @RequestMapping("/") public String hello(@RequestParam("name") Optional<String> name) { if (name.isPresent()) { return "Hello, " + name.get(); } else { return "Hello, John"; } } ãã—ãŸã‚‰ã€å¤šæ–¹é¢ã‹ã‚‰åˆ‡ã‚Œå‘³ã™ã‚‹ã©ã„ãƒ„ã‚¤ãƒ¼ãƒˆãŒé£›ã‚“ã§ãã¾ã—ãŸ ã‚ãƒ¼ã€‚ ãã‚“ãªã‚ã‘ã§ã€ä»Šå›žã®ä¾‹ã§è¨€ãˆã°ã€ã“ã†æ›¸ãã®ãŒã‚«ãƒƒã‚³ã‚¤ã‚¤ã¨æ€ã„ã¾ã™ã€‚ @RequestMapping("/") public String hello(@RequestParam("name") Optional<String> name) { return "Hello, "
bobbyjam99 2014/12/14
java8

optional
ãƒªãƒ³ã‚¯
ã€ŒJavaã«ã‚ˆã‚‹é–¢æ•°åž‹ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã€èªã‚“ã â€” è£ç´™
ã•ãã‚‰ã°ã•ã‚“ã«çŒ®æœ¬ã—ã¦é ‚ãã¾ã—ãŸã€‚ ã‚ã‚ŠãŒã¨ã†ã”ã–ã„ã¾ã™ï¼ Javaã«ã‚ˆã‚‹é–¢æ•°åž‹ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°â€•â€•Java 8ãƒ©ãƒ ãƒ€å¼ã¨Stream ç‰©ç†çš„ã«è–„ã„æœ¬ã§ã™ã—ã€ãƒ©ãƒ ãƒ€å¼ã¨é–¢æ•°åž‹ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã¸ã®å…¥é–€ã¨ã—ã¦è‰¯ã„æœ¬ã ã¨æ€ã„ã¾ã™ã€‚ ãƒãƒ¼ãƒ ã®å¾Œè¼©ã«èªã‚“ã§æ¬²ã—ã„ã€‚ é–¢æ•°åž‹ãƒ—ãƒã‚°ãƒ©ãƒŸãƒ³ã‚°ã¸ã®å…¥é–€ã«ä¸åº¦ã„ã„ã¨ã„ã†ã“ã¨ã§ã€æ•°å¹´å‰ã«ã‚³ãƒƒãƒ—æœ¬ã§å…¥é–€ã‚’æ¸ˆã¾ã›ã¦ã„ãŸç§ã¨ã—ã¦ã¯å°‘ã€…ç‰©è¶³ã‚Šãªã„æ°—ãŒã—ã¾ã—ãŸã€‚ ãŸã ã—7ç« ã¯æœ«å°¾å†å¸°ã®æœ€é©åŒ–ã‚’è¡Œã†ã¨ã„ã†å†…å®¹ã§ã€ãã“ã¯Javaã‚³ãƒ³ãƒ‘ã‚¤ãƒ©ã¯ã‚µãƒãƒ¼ãƒˆã—ã¦ã„ãªã„éƒ¨åˆ†ãªã®ã§èˆˆå‘³æ·±ãèªã¿ã¾ã—ãŸã€‚ æ¥ãšã‹ã—ãªãŒã‚‰ã€æœ«å°¾å†å¸°ã®æœ€é©åŒ–ã‚’è‡ªåˆ†ã§æ›¸ãã¨ã„ã†ç™ºæƒ³ã¯ç„¡ã‹ã£ãŸã®ã§å‚è€ƒã«ãªã‚Šã¾ã™ã€‚ ä»¥ä¸‹ã€æ°—ã«ãªã£ãŸç‚¹ã‚’æŒ™ã’ã¾ã™ã€‚ ã‚¿ã‚¤ãƒã‚‚å«ã‚€ã€‚ 2ã€œ3ãƒšãƒ¼ã‚¸ã€‚å®£è¨€çš„ãªã‚³ãƒ¼ãƒ‰ã¨ã¯ã©ã†ã„ã†ã“ã¨ã‹ã‚’ã€ ã„ããªã‚Šãƒ©ãƒ ãƒ€å¼ã‚’ç™»å ´ã•ã›ã‚‹ã®ã§ã¯ãªãJava 7ã¾ã§ã®èªžå½™ã§èª¬æ˜Žã—ã¦ã„ã‚‹ã®ãŒè‰¯ã„ã§ã™ãã€‚ 28ãƒšãƒ¼ã‚¸ã®ä¾‹2-
bobbyjam99 2014/11/01
java

java8
ãƒªãƒ³ã‚¯
Java8ã§ã€ObjectãŒæŒã¤ãƒ¡ã‚½ãƒƒãƒ‰ã«ã¤ã„ã¦ã¯ã‚¤ãƒ³ã‚¿ãƒ¼ãƒ•ã‚§ãƒ¼ã‚¹ã§defaultå®Ÿè£…ã‚’ã§ããªã„ã‚ˆã†ã«ã—ã¦ã„ã‚‹ç†ç”± - ãªã¿ã²ã‚‰ãƒ–ãƒã‚°
èƒŒæ™¯Java8ã«ã¦ã€ã‚¤ãƒ³ã‚¿ãƒ¼ãƒ•ã‚§ãƒ¼ã‚¹ã«defaultãƒ¡ã‚½ãƒƒãƒ‰ï¼ˆãƒ¡ã‚½ãƒƒãƒ‰å®šç¾©ã¨å®Ÿè£…ï¼‰ã‚’å®šç¾©ã§ãã‚‹ã‚ˆã†ã«ãªã‚Šã¾ã—ãŸã€‚ ã—ã‹ã—ã€ãã®å®Ÿè£…ã«ãŠã„ã¦Objectã‚¯ãƒ©ã‚¹ãŒæŒã£ã¦ã„ã‚‹ãƒ¡ã‚½ãƒƒãƒ‰ï¼ˆtoString()ã¨ã‹equals()ã¨ã‹ï¼‰ã¯ã€ã‚¤ãƒ³ã‚¿ãƒ¼ãƒ•ã‚§ãƒ¼ã‚¹å†…ã§defaultå®Ÿè£…ã¨ã—ã¦å®šç¾©ã§ããªã„ã‚ˆã†ã«ãªã£ã¦ã„ã¾ã™ã€‚ï¼ˆã‚³ãƒ³ãƒ‘ã‚¤ãƒ«ã‚¨ãƒ©ãƒ¼ã€ŒA default method cannot override a method from java.lang.Objectã€ï¼‰ ã€Œãªã‚“ã§ã‹ãªãï½žã€ã¨æ€ã£ã¦ã¡ã‚‡ã£ã¨èª¿ã¹ã¦ã¿ãŸã‚‰ã€ä»¥ä¸‹ã®è¨˜äº‹ã‚’è¦‹ã¤ã‘ã¾ã—ãŸã€‚ ã¡ã‚‡ã£ã¨è¦ç´„ã¡ã‚‡ã£ã¨è¦ç´„ã—ã¦ã¿ã¾ã™ã€‚ ï¼ƒè‡ªåˆ†ã®è§£é‡ˆã‚’ä¸€éƒ¨å…¥ã‚Œã¦ã„ã¾ã™ã€‚ ï¼ƒè‹±èªžã«ä¸è‡ªç”±ã®ãªã„æ–¹ã¯ä¸Šè¨˜ã‚’è¦‹ã¦ã‚‚ã‚‰ãˆã‚Œã°ã„ã„ã‹ã¨æ€ã„ã¾ã™ã€‚ ï¼ˆè³ªå•è€…ï¼‰ defaultãƒ¡ã‚½ãƒƒãƒ‰ã¯ã€Javaã®ä¸ã§æ–°ã—ã„è‰¯ã„ãƒ„ãƒ¼ãƒ«ã ã€‚ ã—ã‹ã—ã€ç§ãŒã‚¤ãƒ³ã‚¿ãƒ¼ãƒ•ã‚§ãƒ¼ã‚¹ã«toString()ã®def
bobbyjam99 2014/10/27
java

java8
ãƒªãƒ³ã‚¯
ç¬¬å…å›žæ¸‹è°·Java Java8ã®JVMç›£è¦–ã‚’è€ƒãˆã‚‹
13. jstat â€¢ PC/PUãŒMC/MU,CCSC/CCSUã«å¤‰æ›´ã•ã‚Œã¦ã„ã‚‹ Java7 $ /usr/java/jdk8/bin/jstat -gc 6516 S0C S1C S0U S1U EC EU OC OU PC PU (ç•¥) 2560.0 2560.0 0.0 0.0 30720.0 317.5 36864.0 15032.1 28672.0 14250.7 (ç•¥) Java8 $ /usr/java/jdk8/bin/jstat -gc 15802 S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU (ç•¥) 4096.0 4096.0 0.0 0.0 32768.0 368.8 14336.0 11029.2 15104.0 14456.5 1792.0 1597.2
bobbyjam99 2014/06/29
java8

Monitoring

java

jvm
ãƒªãƒ³ã‚¯
nanobench - Java 8 ã§ç°¡å˜ã«ãƒžã‚¤ã‚¯ãƒãƒ™ãƒ³ãƒãƒžãƒ¼ã‚¯ã‚’ã¨ã‚Œã‚‹ãƒ•ãƒ¬ãƒ¼ãƒ ãƒ¯ãƒ¼ã‚¯ä½œã£ãŸ - tokuhirom's blog
Caliper ã‚„ JMH ãªã©ã‚’è©¦ã—ã¦ã¿ãŸãŒï½¤æ¡ˆå¤–ã‚ã‚Œã¯ä½¿ã†ã®ãŒé›£ã—ã‹ã£ãŸã‚Šï½¤ã‚¤ãƒ³ã‚¹ãƒˆãƒ¼ãƒ«ãŒé›£ã—ã‹ã£ãŸã‚Šï½¤çµæžœãŒã‚ˆã¿ã¥ã‚‰ã‹ã£ãŸã‚Šã™ã‚‹ï½¡ Perl 5 ã«æ¨™æº–æ·»ä»˜ã•ã‚Œã¦ã„ã‚‹ãƒ™ãƒ³ãƒãƒžãƒ¼ã‚¯ãƒ•ãƒ¬ãƒ¼ãƒ ãƒ¯ãƒ¼ã‚¯ã§ã‚ã‚‹ã¨ã“ã‚ã® Benchmark.pm ã¨åŒã˜ãã‚‰ã„æ°—è»½ãªæ„Ÿã˜ã§ä½¿ãˆã‚‹ãƒ™ãƒ³ãƒãƒžãƒ¼ã‚¯ãƒ•ãƒ¬ãƒ¼ãƒ ãƒ¯ãƒ¼ã‚¯ãŒ Java 8 ç”¨ã«ã‚ã‚Œã°ä¾¿åˆ©ãªã®ã§ã¯ãªã„ã‹ï½¤ã¨æ€ã£ãŸã®ã§ä½œã£ã¦ã¿ãŸï½¡ https://github.com/tokuhirom/nanobench å…ˆæ—¥ã¤ãã£ãŸ HTML escape ã«é–¢ã™ã‚‹ãƒžã‚¤ã‚¯ãƒãƒ™ãƒ³ãƒãƒžãƒ¼ã‚¯ã‚’ nanobench ã‚’ä½¿ã£ã¦æ›¸ããªãŠã—ã¦ã¿ã‚‹ï½¡ package me.geso.microbenchmarks; import me.geso.nanobench.Benchmark; import org.apache.commons.lang3.StringEscapeUtil
bobbyjam99 2014/06/27
java8

benchmark
ãƒªãƒ³ã‚¯
1 2 3 æ¬¡ã®ãƒšãƒ¼ã‚¸