| 澶辨晥閾炬帴澶勭悊 |
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“涔愯閿?rdquo;杞繪澗鎼炲畾楂樺茍鍙戜笅鐨勫箓絳夋€ч棶棰樺疄鎴樿棰戞暀紼?/strong> 涓撻甯栧瓙 鍏紬鍙峰笘瀛?/span> 瑙嗛鏁欑▼ “涔愯閿?rdquo;杞繪澗鎼炲畾楂樺茍鍙戜笅鐨勫箓絳夋€ч棶棰樺疄鎴樿棰戞暀紼?/strong> 鐩稿叧鎴浘錛?br />   涓昏鍐呭錛?/strong>
浠€涔堟槸騫傜瓑鎬э紵
騫傜瓑錛坕dempotent銆乮dempotence錛夋槸涓€涓暟瀛︿笌璁＄畻鏈哄姒傚康錛屽父瑙佷簬鎶借薄浠ｆ暟涓€傚湪緙栫▼涓?涓€涓箓絳夋搷浣滅殑鐗圭偣鏄叾浠繪剰澶氭鎵ц鎵€浜х敓鐨勫獎(jiǎng)鍝嶅潎涓庝竴嬈℃墽琛岀殑褰卞搷鐩稿悓銆傚箓絳夊嚱鏁幫紝鎴栧箓絳夋柟娉曪紝鏄寚鍙互浣跨敤鐩稿悓鍙傛暟閲嶅鎵ц錛屽茍鑳借幏寰楃浉鍚岀粨鏋滅殑鍑芥暟銆傝繖浜涘嚱鏁頒笉浼?xì)濯?jiǎng)鍝嶇郴緇熺姸鎬侊紝涔熶笉鐢ㄦ媴蹇?jī)閲嶅鎵ц浼?xì)瀵圭郴緇熼€犳垚鏀瑰彉銆備緥濡傦紝“getUsername()鍜宻etTrue()”鍑芥暟灝辨槸涓€涓箓絳夊嚱鏁? 鏇村鏉傜殑鎿嶄綔騫傜瓑淇濊瘉鏄埄鐢ㄥ敮涓€浜ゆ槗鍙?嫻佹按鍙?瀹炵幇. 鎴戠殑鐞嗚В錛氬箓絳夊氨鏄竴涓搷浣滐紝涓嶈鎵ц澶氬皯嬈★紝浜х敓鐨勬晥鏋滃拰榪斿洖鐨勭粨鏋滈兘鏄竴鏍風(fēng)殑 銆?/div>
楂樺茍鍙戜笅鐨勫箓絳夋€ч棶棰?/div>
榪欓噷浠ヤ袱涓疄渚嬫潵鐪嬩笅楂樺茍鍙戜笅鐨勫箓絳夋€ч棶棰橈紱
涓€錛岃喘紲ㄥ疄渚?/div>
璐エ瀹炵幇嫻佺▼濡備笅錛?/div>
step1錛氭煡璇㈡槸鍚︽湁紲紝鏈夌エ鐨勮瘽錛岀戶緇笅涓€姝ワ紝鍚﹀垯鎻愮ず鏃犵エ錛岀粨鏉燂紱
step2錛氫粠鐢ㄦ埛璐︽埛鎵ｉ櫎紲ㄦ錛?/div>
step3錛氫綑紲ㄥ噺涓€鎿嶄綔錛?/div>
榪欓噷鐨勮瘽錛屾甯告儏鍐墊病闂錛屼絾鏄瘮濡傜敤鎴瘋繛緇鐐逛簡(jiǎn)鍑犳錛屾垨鑰呯綉緇滈棶棰樺鑷寸殑鍐嶆垨鑰呭浜哄悓鏃惰喘涔扮殑鏃跺€欑殑騫跺彂鎯呭喌涓嬶紝step1姝ラ浼?xì)鏈変袱涓垨鑰呭涓嚎紼嬪悓鏃惰繘鍏ワ紝榪欐椂鍊欏垽鏂兘鏄湁紲ㄧ殑錛岀劧鍚庣戶緇繘鍏tep2錛宻tep3錛岃繖鏃跺€欙紝灝卞彲鑳戒細(xì)鍑虹幇浣欑エ璐熸暟錛屽鍗栫殑鎯呭喌錛?/div>
浜岋紝鍏呭€煎疄渚?/div>
鍏呭€煎疄鐜版祦紼嬪涓嬶細(xì)
step1錛氱敤鎴瘋緭鍏ュ厖鍊奸噾棰濓紝璇鋒眰鍚庣涓氬姟緋葷粺錛?/div>
step2錛氬悗绔敓鎴愯鍗曪紝璁㈠崟鐘舵€佹槸鏈敮浠橈紝鐒跺悗鍐嶈姹傜涓夋柟鏀粯鎺ュ彛錛?/div>
step3錛氱敤鎴風(fēng)紜鏀粯錛?/div>
step4錛氱涓夋柟鏀粯閫氳繃鎴戞柟鎻愪緵鐨勫洖璋冩帴鍙ｅ紓姝ラ€氱煡鏀粯緇撴灉錛?/div>
鍏蜂綋step4 demo浠ｇ爜濡備笅錛?/div>
System.out.println("鏌ヨ璁㈠崟");
Order order = orderMapper.getByOrderId(orderId); // 鏍規(guī)嵁璁㈠崟id鑾峰彇璁㈠崟
if(order.getStatus()==0){ // 鍋囧鏄湭鏀粯鐘舵€?/div>
System.out.println("鏈敮浠樼姸鎬?quot;);
order.setStatus(1); // 璁劇疆鏀粯鎴愬姛鐘舵€?/div>
System.out.println("鏇存柊鏀粯鐘舵€?..");
orderMapper.update(order); // 鏇存柊鏀粯鐘舵€?/div>
System.out.println("璐︽埛鍏呭€?..");
userAccountMapper.addAmount(order.getAmount(),userAccount.getUserId()); // 璐︽埛鍏呭€?/div>
System.out.println("鍏呭€煎畬姣?..");
return true;
}else{ // 宸茬粡鏀粯鎴愬姛錛岃鍗曞凡澶勭悊
System.out.println("鍙戠幇璁㈠崟宸插鐞?quot;);
return true;
}
榪欎釜絎洓姝ユ槸鏈夌己闄風(fēng)殑錛屽亣濡傜涓夋柟鏀粯緋葷粺闂鎴栬€呯綉緇滈棶棰橈紝鏈夊涓嚎紼嬪悓鏃舵墽琛岃繘鍏?nbsp;
Order order = orderMapper.getByOrderId(orderId);
鏍規(guī)嵁璁㈠崟id鏌ヨ璁㈠崟淇℃伅錛屽彂鐜皊tatus鐘舵€侀兘鏄湭鏀粯錛屾墍浠ラ兘榪涘叆if閲岄潰錛岃繖鏃跺€欏氨鍑虹幇浜?jiǎn)杼庢埛閲嶅鍏呭€肩殑鎯呭喌錛?/div>
騫傜瓑鎬ч棶棰樻€葷粨
鍙鏇存柊鏁版嵁鏄緷璧栬鍙栫殑鏁版嵁浣滀負(fù)鍩虹鏉′歡鐨勶紝褰撻亣鍒伴珮騫跺彂鐨勬椂鍊欙紝灝卞彲鑳戒細(xì)鍑虹幇騫傜瓑鎬ч棶棰橈紱
鍙堟瘮濡傚湪鏇存柊鏁版嵁涓嶄緷璧栨煡璇㈢殑鏁版嵁鐨勫氨涓嶄細(xì)鏈夐棶棰橈紝渚嬪淇敼鐢ㄦ埛鐨勫悕縐幫紝澶氫漢鍚屾椂淇敼錛岀粨鏋滃茍涓嶄緷璧栦簬涔嬪墠鐨勭敤鎴峰悕瀛楋紝榪欏氨涓嶄細(xì)鏈夊茍鍙戞洿鏂伴棶棰樸€?/div>
騫傜瓑鎬ч棶棰樿В鍐蟲(chóng)柟妗?/div>
鍏充簬騫傜瓑鎬ч棶棰樼殑瑙ｅ喅鏂規(guī)錛屼笟鐣屾彁渚涗簡(jiǎn)寰堝瑙ｅ喅鏂規(guī)錛屽鍗曟満緋葷粺鐨凧ava 鍚屾閿侊紝涔愯閿侊紝鎮(zhèn)茶閿侊紝鍒嗗竷寮忛攣錛屽敮涓€鎬х儲(chǔ)寮曪紝token鏈哄埗闃叉欏甸潰閲嶅鎻愪氦絳夛紝姣忕鏂規(guī)鍚勬湁鍒╁紛錛涗笉榪囦富嫻佺殑璇濓紝榪樻槸涔愯閿佸拰鍒嗗竷寮忛攣榪欎袱涓柟妗堬紱
Java鍚屾閿佹柟妗?/div>
鎴戜滑鍙互浣跨敤synchronized鍚屾閿侊紝鎶婃煡璇㈢姸鎬佺殑浠ｇ爜鍜屾洿鏂扮殑浠ｇ爜鏀句竴涓悓姝ラ攣鍐咃紝榪欐牱鍚屼竴鏃跺埢鍙兘鏈変竴涓嚎紼嬭繘鍏ユ墽琛岋紝絳夋墽琛屽畬鍏朵粬綰跨▼鎵嶈兘榪涘叆錛岃繖鏍瘋兘瑙ｅ喅騫傜瓑鎬ч棶棰橈紝浣嗘槸鍋囧鍚屾鍧楅噷闈㈢殑涓氬姟浠ｇ爜鎵ц鏃墮棿姣旇緝闀匡紝榪欐牱浼?xì)涓ラ噸濯?jiǎng)鍝嶇敤鎴蜂綋楠岋紝鍜岀郴緇熺殑鍚炲悙閲忋€傛墍浠ヤ笉鏄渶浣蟲(chóng)柟妗堬紱
鎮(zhèn)茶閿佹柟妗?/div>
鎮(zhèn)茶閿侊紙Pessimistic Lock錛夛紝欏懼悕鎬濅箟錛屽氨鏄緢鎮(zhèn)茶錛屾瘡嬈″幓鎷挎暟鎹殑鏃跺€欓兘璁や負(fù)鍒漢浼?xì)淇敼锛屾墍浠ユ瘡嬈″湪鎷挎暟鎹殑鏃跺€欓兘浼?xì)涓婇攣锛寴q欐牱鍒漢鎯蟲(chóng)嬁榪欎釜鏁版嵁灝變細(xì)block鐩村埌瀹冩嬁鍒伴攣銆?/div>
鎮(zhèn)茶閿侊細(xì)鍋囧畾浼?xì)鍙戠敓迤堝彂鍐步H侊紝灞忚斀涓€鍒囧彲鑳借繚鍙嶆暟鎹畬鏁存€х殑鎿嶄綔銆?/div>
Java synchronized 灝卞睘浜庢?zhèn)茶閿佺殑涓€縐嶅疄鐜幫紝姣忔綰跨▼瑕佷慨鏀規(guī)暟鎹椂閮藉厛鑾峰緱閿侊紝淇濊瘉鍚屼竴鏃跺埢鍙湁涓€涓嚎紼嬭兘鎿嶄綔鏁版嵁錛屽叾浠栫嚎紼嬪垯浼?xì)琚玝lock銆?/div>
鏁版嵁搴撶殑鎮(zhèn)茶閿侀€氳繃 for update 瀹炵幇鐨勶紱
select * from t_order where orderId=#{orderId} for update
鎮(zhèn)茶閿佷嬌鐢ㄦ椂涓€鑸即闅忎簨鍔′竴璧蜂嬌鐢紝鏁版嵁閿佸畾鏃墮棿鍙兘浼?xì)寰堥暱锛屽奖鍝嶇敤鎴蜂綋楠屽拰绯痪l熷悶鍚愰噺錛屾墍浠ヤ竴鑸篃涓嶉噰鐢ㄣ€?/div>
涔愯閿佹柟妗?/div>
涔愯閿侊紙Optimistic Lock錛夛紝欏懼悕鎬濅箟錛屽氨鏄緢涔愯錛屾瘡嬈″幓鎷挎暟鎹殑鏃跺€欓兘璁や負(fù)鍒漢涓嶄細(xì)淇敼錛屾墍浠ヤ笉浼?xì)涓婇攣锛屼絾鏄湪鎻愪氦鏇存柊鐨勬椂鍊欎細(xì)鍒ゆ柇涓€涓嬪湪姝ゆ湡闂村埆浜烘湁娌℃湁鍘繪洿鏂拌繖涓暟鎹€備箰瑙傞攣閫傜敤浜庤澶氬啓灝戠殑搴旂敤鍦烘櫙錛岃繖鏍峰彲浠ユ彁楂樺悶鍚愰噺銆?/div>
涔愯閿侊細(xì)鍋囪涓嶄細(xì)鍙戠敓騫跺彂鍐茬獊錛屽彧鍦ㄦ彁浜ゆ搷浣滄椂媯€(gè)鏌ユ槸鍚﹁繚鍙嶆暟鎹畬鏁存€с€?/div>
涔愯閿佷竴鑸潵璇存湁浠ヤ笅2縐嶆柟寮忥細(xì)
1. 浣跨敤鏁版嵁鐗堟湰錛圴ersion錛夎褰曟満鍒跺疄鐜幫紝榪欐槸涔愯閿佹渶甯哥敤鐨勪竴縐嶅疄鐜版柟寮忋€備綍璋撴暟鎹増鏈紵鍗充負(fù)鏁版嵁澧炲姞涓€涓増鏈爣璇嗭紝涓€鑸槸閫氳繃涓烘暟鎹簱琛ㄥ鍔犱竴涓暟瀛楃被鍨嬬殑 “version” 瀛楁鏉ュ疄鐜般€傚綋璇誨彇鏁版嵁鏃訛紝灝唙ersion瀛楁鐨勫€間竴鍚岃鍑猴紝鏁版嵁姣忔洿鏂頒竴嬈★紝瀵規(guī)version鍊煎姞涓€銆傚綋鎴戜滑鎻愪氦鏇存柊鐨勬椂鍊欙紝鍒ゆ柇鏁版嵁搴撹〃瀵瑰簲璁板綍鐨勫綋鍓嶇増鏈俊鎭笌絎竴嬈″彇鍑烘潵鐨剉ersion鍊艱繘琛屾瘮瀵癸紝濡傛灉鏁版嵁搴撹〃褰撳墠鐗堟湰鍙蜂笌絎竴嬈″彇鍑烘潵鐨剉ersion鍊肩浉絳夛紝鍒欎簣浠ユ洿鏂幫紝鍚﹀垯璁や負(fù)鏄繃鏈熸暟鎹€?nbsp;
2. 浣跨敤鏃墮棿鎴籌紙timestamp錛夈€備箰瑙傞攣瀹氱殑絎簩縐嶅疄鐜版柟寮忓拰絎竴縐嶅樊涓嶅錛屽悓鏍鋒槸鍦ㄩ渶瑕佷箰瑙傞攣鎺у埗鐨則able涓鍔犱竴涓瓧孌碉紝鍚嶇О鏃犳墍璋擄紝瀛楁綾誨瀷浣跨敤鏃墮棿鎴籌紙timestamp錛? 鍜屼笂闈㈢殑version綾諱技錛屼篃鏄湪鏇存柊鎻愪氦鐨勬椂鍊欐鏌ュ綋鍓嶆暟鎹簱涓暟鎹殑鏃墮棿鎴沖拰鑷繁鏇存柊鍓嶅彇鍒扮殑鏃墮棿鎴寵繘琛屽姣旓紝濡傛灉涓€鑷村垯OK錛屽惁鍒欏氨鏄増鏈啿紿併€?/div>
涔愯閿佹柟妗堝湪涓嶅獎(jiǎng)鍝嶇郴緇熸€ц兘鐨勬儏鍐典笅錛岃В鍐充簡(jiǎn)楂樺茍鍙戝箓絳夋€ч棶棰橈紝鎵€浠ヨ寰楀埌騫挎硾浣跨敤銆傚敮涓€鐨勭己鐐瑰氨鏄浠ｇ爜鍏鋒湁鍏ヤ鏡鎬с€?/div>
鍒嗗竷寮忛攣
瀵逛簬鍒嗗竷寮忕郴緇燂紝澶氫釜緋葷粺鐙珛榪愯錛屾墍浠ュ悓姝ラ攣鑲畾鏄笉琛岀殑錛涘浜庡垎甯冨紡緋葷粺錛屽彲浠ョ敤涔愯閿佹垨鑰呭垎甯冨紡閿佹潵瑙ｅ喅騫傜瓑鎬ч棶棰橈紱
鍏蜂綋鏂規(guī)鏈夛細(xì)
1. 鍩轟簬緙撳瓨錛圧edis絳夛級(jí)瀹炵幇鍒嗗竷寮忛攣錛?/div>
2. 鍩轟簬Zookeeper瀹炵幇鍒嗗竷寮忛攣錛?/div>
錛堝娉細(xì)涓嬫湡鎴戜滑浼?xì)鎻愪緵鍏蜂綋瀹炵幇鏂规鐨勮棰戞暀绋嬪Q屾劅璋㈠叧娉級(jí)
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| Java1234瀹樻柟緹?5錛?/td> | 
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| Java1234瀹樻柟緹?5錛?/td> | 838462530 |
鑻忓叕緗戝畨澶?32061202001004鍙?/p>
