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j5ik2o id:j5ik2o

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Javaã«ã‚ˆã‚‹é«˜éšŽåž‹å¤‰æ•°ã®å®Ÿè£… - ãƒ—ãƒã‚°ãƒ©ãƒžãƒ¼ã®è„³ã¿ã
é«˜éšŽé–¢æ•°ã¨ã„ã†ã‚‚ã®ã‚’ã”å˜çŸ¥ã‹ã€‚é–¢æ•°è‡ªèº«ã‚’å¼•æ•°ã‚ã‚‹ã„ã¯æˆ»ã‚Šå€¤ã«å–ã‚‹é–¢æ•°ã®ã“ã¨ã§ã‚ã‚‹ã€‚ã€Œé«˜éšŽã€ã¯ã€Œã“ã†ã‹ã„ã€ã¨èªã‚€ã€‚ãã®æ˜”ã€ŒãŸã‹ã—ãªã€ã¨èªã‚“ã äººãŒã„ãŸã¨ã‹ã€ã„ãªã„ã¨ã‹ã€‚ å…ˆã®ã‚¨ãƒ³ãƒˆãƒªã€ŒHttpSessionã‚’åž‹å®‰å…¨ã«ã™ã‚‹ã€ã§ã¯ã€Œjavax.servlet.http.HttpSessionã®setAttribute()/getAttribute()ã®ã‚ˆã†ãªãƒ¢ãƒŽã‚’ã©ã†ã‚„ã£ã¦åž‹å®‰å…¨ã«ã™ã‚‹ã‹ã€ã¨ã„ã†å‹•æ©Ÿä»˜ã‘ã‹ã‚‰ã€ public class KeyValue<K> { public <T> void put(K<T> key, T value){} } ã¨ã„ã£ãŸã“ã¨ã‚’ã‚„ã‚ã†ã¨ã—ã¦ã€Javaã®è¨€èªžä»•æ§˜ä¸Šã€åž‹å¤‰æ•°ã«åž‹å¤‰æ•°ã‚’æŒãŸã›ã‚‹ã“ã¨ãŒã§ããªã„ã®ã§å®Ÿç¾ã§ããªã„ã¨è¿°ã¹ãŸã€‚ ç°¡å˜ã«è§£èª¬ã™ã‚‹ã¨ã€ã“ã“ã§KayValueã¯HashMapçš„ãªã‚ãƒ¼ã‚’æ¸¡ã›ã°å€¤ã‚’è¿”ã™ã‚ªãƒ–ã‚¸ã‚§ã‚¯ãƒˆã§ã€åž‹å¤‰æ•°Kã¯ã‚ãƒ¼ã®é›†åˆä½“ã‚’è¡¨ç¾ã—ã¦ã„ã‚‹ã€‚ty
j5ik2o 2011/01/26
java

generics
ãƒªãƒ³ã‚¯
å…±å¤‰ï¼ˆcovariantï¼‰ [/dev/nullpo]
Java5ã‹ã‚‰ãƒ¡ã‚½ãƒƒãƒ‰ã‚’ã‚ªãƒ¼ãƒãƒ¼ãƒ©ã‚¤ãƒ‰ã™ã‚‹ã¨ãã€æˆ»ã‚Šå€¤ã®åž‹ã‚’å¤‰æ›´ã™ã‚‹ã“ã¨ãŒå¯èƒ½ã«ãªã£ãŸã€‚ å…±å¤‰æˆ»ã‚Šå€¤ã¯cloneãƒ¡ã‚½ãƒƒãƒ‰ã§æœ€ã‚‚ã‚ˆãåˆ©ç”¨ã•ã‚Œã‚‹ã€‚ public interface Cloneable{ public Object clone(); } public class CloneableImpl implements Cloneable{ public CloneableImpl clone() { try { return (CloneableImpl)super.clone(); } catch (CloneNotSupportedException e) { throw new InternalError(e.getMessage()); } } } CloneableImplã¯Objectã®ä¸€ã¤ã§ã‚ã‚‹ã®ã§ã€CloneableImpl clone();ã¯Objectã‚’è¿”ã—ã¦ã„ã‚‹
j5ik2o 2010/11/02
generics
ãƒªãƒ³ã‚¯
Generic commons-collections
j5ik2o 2010/05/25
commons

apache

generics
ãƒªãƒ³ã‚¯
Java Reflection - Generics
I have often read in articles and forums that all Java Generics information is erased at compile time so that you cannot access any of that information at runtime. This is not entirely true though. It is possible to access generics information at runtime in a handful of cases. These cases actually cover several of our needs for Java Generics information. This text explains these cases. The Generic
j5ik2o 2010/02/27
java

generics

reflection
ãƒªãƒ³ã‚¯
genericsã®åž‹æƒ…å ± - ãŸã·ã¤ãã¾ã›ã‚“
ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿ä»˜ãã§ã‚¤ãƒ³ã‚¹ã‚¿ãƒ³ã‚¹ç”Ÿæˆã—ãŸã‚ªãƒ–ã‚¸ã‚§ã‚¯ãƒˆã«å¯¾ã—ã¦ãƒ‘ãƒ©ãƒ¡ãƒ¼ã‚¿åž‹ã«ä½•ã‚’æ¸¡ã•ã‚ŒãŸã‹ãƒªãƒ•ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã§çŸ¥ã‚‹ã“ã¨ãŒã§ãã‚‹ã‹ã‚’èª¿æŸ»ã—ã¾ã—ãŸã€‚çµæžœã‚’ãƒ¡ãƒ¢ã—ã¦ãŠãã¾ã™ã€‚ã¾ã•ãŸã‹ã•ã‚“ã®åˆæœŸikushipeã‚³ãƒ¼ãƒ‰ãŒå‚è€ƒã«ãªã‚Šã¾ã—ãŸã€‚ã‚ã‚ŠãŒã¨ã†ã”ã–ã„ã¾ã™ã€‚ã•ã„ã—ã‚‡ã¯ParameterizedType, TypeVariable, getTypeParameters() ãŒãã‚Œãžã‚Œä½•ã‚’ã—ã‚ã™ã‹åˆ†ã‹ã‚Šã¾ã›ã‚“ã§ã—ãŸã®ã§ã€ã¾ãšã“ã‚Œã‚’æ•´ç†ã—ã¦ãŠãã¾ã™ã€‚ ä»¥ä¸‹ã¯å€¤åž‹ã ã‘Stringã«å›ºå®šã—ãŸHashMapã‚¯ãƒ©ã‚¹ã®ä¾‹ã§ã™ã€‚ class MyStringMap<K> extends HashMap<K, String> {} ~~~ï¼¼ ~~~~~~~~~~~~~~~~~~ï¼¼ getTypeParameters() getGenericSuperClass() ï¼¼ ï¼¼ Kã¯TypeVariableåž‹ ã“ã®å ´åˆã€instan
j5ik2o 2010/02/27
java

generics

reflection
ãƒªãƒ³ã‚¯
IBM Developer
IBM Developer is your one-stop location for getting hands-on training and learning in-demand skills on relevant techno logies such as generative AI, data science, AI, and open source.
j5ik2o 2009/10/19
generics

java
ãƒªãƒ³ã‚¯
IBM Developer
IBM Developer is your one-stop location for getting hands-on training and learning in-demand skills on relevant techno logies such as generative AI, data science, AI, and open source.
j5ik2o 2009/10/19
generics
ãƒªãƒ³ã‚¯
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