Java Stream流必备方法大全：从filter到collect的实战技巧解析-嘻道妙招

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鈥?strong>鈥嬧枍filter() - 浣犵殑鏁版嵁绛涘瓙鈥?/strong>鈥?br/> 锛堟暡榛戞澘锛夎繖缁濆鏄娇鐢ㄧ巼TOP1鐨勬柟娉曪紒鎯宠薄浣犳湁涓€绛愯嫻鏋滐紝鍙兂鎸戝嚭绾㈣嫻鏋滐紝浠ｇ爜鎬庝箞鍐欙紵

java澶嶅埗List redApples = apples.stream()
    .filter(apple -> "red".equals(apple.getColor())) //鈫愰噸鐐圭湅杩欙紒
    .collect(Collectors.toList());

鈥?strong>鈥嬸煈?鍒掗噸鐐光€?/strong>鈥嬶細

鈥?strong>鈥嬧枍map() - 鍙樺舰閲戝垰寮忔搷浣溾€?/strong>鈥?br/> 鎯宠鎶婅嫻鏋滃璞″彉鎴愯嫻鏋滈噸閲忥紵鐪嬪ソ浜嗭紒

java澶嶅埗List weights = apples.stream()
    .map(Apple::getWeight)  // 鏂规硶寮曠敤鏇寸畝娲?/span>
    .collect(Collectors.toList());

鈥?strong>鈥嬸焼?瀵规瘮浼犵粺鍐欐硶鈥?/strong>鈥?/p>

Stream鍐欐硶	for寰幆鍐欐硶
1琛屼唬鐮佹悶瀹?/td>	闇€瑕?-5琛?/td>
閾惧紡璋冪敤瓒呮竻鏅?/td>	瀹规槗宓屽娣蜂贡

锛堢獊鐒舵媿澶ц吙锛夊浜嗭紒閬囧埌宓屽闆嗗悎灏辩敤鈥?strong>鈥媐latMap鈥?/strong>鈥嬶紝鍍忓墺娲嬭懕涓€鏍锋妸鏁版嵁鎽婂钩锛?/p>

鈥?strong>鈥嬧枍collect() - 缁堟瀬鏀跺壊鑰呪€?/strong>鈥?br/> 锛堜弗鑲冭劯锛夎繖鏄暣涓祦姘寸嚎鐨勬敹灏惧ぇ鎷涳紒涓句釜鏍楀瓙锛氭兂鎶婅嫻鏋滄寜棰滆壊鍒嗙粍鎬庝箞鍔烇紵

java澶嶅埗Map> colorGroups = apples.stream()
    .collect(Collectors.groupingBy(Apple::getColor));

鈥?strong>鈥嬸煂?鏇村楠氭搷浣溾€?/strong>鈥嬶細

鈥?strong>鈥嬧枍骞惰娴佺湡棣欒鍛婏紒鈥?/strong>鈥?br/> 锛堢獊鐒跺帇浣庡０闊筹級鍋峰伔鍛婅瘔浣狅紝鍙鍔犱釜parallel()锛屽鐞嗙櫨涓囨暟鎹揩寰楅璧凤細

java澶嶅埗List bigApples = apples.parallelStream()
    .filter(a -> a.getWeight() > 150)
    .collect(Collectors.toList());

鈥?strong>鈥嬧殸锔?浣嗘槸娉ㄦ剰鈥?/strong>鈥嬶細

鈥?strong>鈥嬧枍璋冭瘯澶ф硶锛歱eek()鈥?/strong>鈥?br/> 锛堟媿妗屽瓙锛夎繖涓鍣ㄥ繀椤诲畨鍒╋紒鍍忚皟璇曟椂鎵撳嵃鏃ュ織锛?/p>

java澶嶅埗apples.stream()
    .peek(a -> System.out.println("褰撳墠澶勭悊锛?+a)) //鈫愮湅杩欓噷
    .filter(...)

Stream铏藉ソ锛屽彲鍒椽鏉紒绠€鍗曞惊鐜繕鏄敤for鏇寸洿瑙傘€備絾瑕佽澶勭悊澶嶆潅鏁版嵁鈥斺€旓紙鎷夐暱闊筹級閭ｅ繀椤诲緱鏄疭tream鐨勫ぉ涓嬶紒璇曠潃鐢ㄤ粖澶╁鐨勬柟娉曟敼閫犱綘鐨勬棫浠ｇ爜锛屼繚鍑嗗悓浜嬬洿鍛煎唴琛岋紒

锛堢獊鐒舵敹灏撅級濂戒簡涓嶅暟鍡︿簡锛岃刀绱ф墦寮€IDE瀹炴搷鍚э紒閬囧埌闂璇勮鍖鸿锝?/p>

本文由嘻道妙招独家原创，未经允许，严禁转载

Java Stream流必备方法大全：从filter到collect的实战技巧解析