{"id":10216,"date":"2023-11-28T21:29:47","date_gmt":"2023-11-28T13:29:47","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=10216"},"modified":"2023-11-28T21:29:52","modified_gmt":"2023-11-28T13:29:52","slug":"java-zhong-copyonwritearraylist-shi-shen-me","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/java-zhong-copyonwritearraylist-shi-shen-me\/","title":{"rendered":"Java \u4e2d CopyOnWriteArrayList \u662f\u4ec0\u4e48\uff1f"},"content":{"rendered":"<p>CopyOnWriteArrayList\u662f\u4e00\u4e2a\u5e76\u53d1\u5bb9\u5668\u3002\u6709\u5f88\u591a\u4eba\u79f0\u5b83\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u6211\u8ba4\u4e3a\u8fd9\u53e5\u8bdd\u4e0d\u4e25\u8c28\uff0c \u7f3a\u5c11\u4e00\u4e2a\u524d\u63d0\u6761\u4ef6\uff0c\u90a3\u5c31\u662f\u975e\u590d\u5408\u573a\u666f\u4e0b\u64cd\u4f5c\u5b83\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002<br \/>\nCopyOnWriteArrayList (\u514d\u9501\u5bb9\u5668)\u7684\u597d\u5904\u4e4b\u4e00\u662f\u5f53\u591a\u4e2a\u8fed\u4ee3\u5668\u540c\u65f6\u904d\u5386\u548c\u4fee\u6539\u8fd9\u4e2a\u5217\u8868\u65f6\uff0c\u4e0d\u4f1a\u629b\u51fa ConcurrentModificationException\u3002 \u5728 CopyOnWriteArrayList \u4e2d\uff0c\u5199\u5165\u5c06\u5bfc\u81f4\u521b\u5efa \u6574\u4e2a\u5e95\u5c42\u6570\u7ec4\u7684\u526f\u672c\uff0c\u800c\u6e90\u6570\u7ec4\u5c06\u4fdd\u7559\u5728\u539f\u5730\uff0c\u4f7f\u5f97\u590d\u5236\u7684\u6570\u7ec4\u5728\u88ab\u4fee\u6539\u65f6\uff0c\u8bfb\u53d6\u64cd\u4f5c\u53ef\u4ee5\u5b89 \u5168\u5730\u6267\u884c\u3002<br \/>\nCopyOnWriteArrayList \u7b80\u4ecb<br \/>\npublic class CopyOnWriteArrayList<E><br \/>\nimp1ements List<E>, RandomAccess, Cloneable, java.io.Serializable {<br \/>\n}<br \/>\n\u5728\u5f88\u591a\u5e94\u7528\u573a\u666f\u4e2d\uff0c\u8bfb\u64cd\u4f5c\u53ef\u80fd\u4f1a\u8fdc\u8fdc\u5927\u4e8e\u5199\u64cd\u4f5c\u3002\u7531\u4e8e\u8bfb\u64cd\u4f5c\u6839\u672c\u4e0d\u4f1a\u4fee\u6539\u539f\u6709\u7684\u6570\u636e\uff0c\u56e0\u6b64\u5982\u679c\u6bcf\u6b21\u8bfb\u53d6\u90fd\u8fdb\u884c\u52a0\u9501\u64cd\u4f5c\uff0c\u5176\u5b9e\u662f\u4e00\u79cd\u8d44\u6e90\u6d6a\u8d39\u3002\u6211\u4eec\u5e94\u8be5\u5141\u8bb8\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8bbf\u95eeList \u7684\u5185\u90e8\u6570\u636e\uff0c\u6bd5\u7adf\u8bfb\u64cd\u4f5c\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002<br \/>\n\u8fd9\u548cReentrantReadWriteLock\u8bfb\u5199\u9501\u7684\u601d\u60f3\u975e\u5e38\u7c7b\u4f3c\uff0c\u4e5f\u5c31\u662f\u8bfb\u8bfb\u5171\u4eab\u3001\u5199\u5199\u4e92\u65a5\u3001\u8bfb\u5199 \u4e92\u65a5\u3001\u5199\u8bfb\u4e92\u65a5\u3002JDK\u4e2d\u63d0\u4f9b\u4e86 CopyOnWriteArrayList\u7c7b\uff0c\u76f8\u6bd4\u4e8e\u5728\u8bfb\u5199\u9501\u7684\u601d\u60f3\u53c8\u66f4\u8fdb\u4e00\u6b65\u3002\u4e3a\u4e86\u5c06\u8bfb\u53d6\u7684\u6027\u80fd\u53d1\u6325\u5230\u6781\u81f4\uff0cCopyOnWriteArrayList\u8bfb\u53d6\u662f\u5b8c\u5168\u4e0d\u7528\u52a0\u9501\u7684\uff0c\u5e76\u4e14\u66f4 \u5389\u5bb3\u7684\u662f\uff1a\u5199\u5165\u4e5f\u4e0d\u4f1a\u963b\u585e\u8bfb\u53d6\u64cd\u4f5c\uff0c\u53ea\u6709\u5199\u5165\u548c\u5199\u5165\u4e4b\u95f4\u9700\u8981\u8fdb\u884c\u540c\u6b65\u7b49\u5f85\uff0c\u8bfb\u64cd\u4f5c\u7684\u6027\u80fd \u5f97\u5230\u5927\u5e45\u5ea6\u63d0\u5347\u3002<br \/>\nCopyOnWriteArrayList \u662f\u5982\u4f55\u505a\u5230\u7684<br \/>\nCopyOnWriteArrayList\u7c7b\u7684\u6240\u6709\u53ef\u53d8\u64cd\u4f5c\uff08add, set\u7b49\u7b49\uff09\u90fd\u662f\u901a\u8fc7\u521b\u5efa\u5e95\u5c42\u6570\u7ec4\u7684\u65b0\u526f\u672c \u6765\u5b9e\u73b0\u7684\u3002\u5f53List\u9700\u8981\u88ab\u4fee\u6539\u7684\u65f6\u5019\uff0c\u5e76\u4e0d\u76f4\u63a5\u4fee\u6539\u539f\u6709\u6570\u7ec4\u5bf9\u8c61\uff0c\u800c\u662f\u5bf9\u539f\u6709\u6570\u636e\u8fdb\u884c\u4e00 \u6b21\u62f7\u8d1d\uff0c\u5c06\u4fee\u6539\u7684\u5185\u5bb9\u5199\u5165\u526f\u672c\u4e2d\u3002\u5199\u5b8c\u4e4b\u540e\uff0c\u518d\u5c06\u4fee\u6539\u5b8c\u7684\u526f\u672c\u66ff\u6362\u6210\u539f\u6765\u7684\u6570\u636e\uff0c\u8fd9\u6837\u5c31 \u53ef\u4ee5\u4fdd\u8bc1\u5199\u64cd\u4f5c\u4e0d\u4f1a\u5f71\u54cd\u8bfb\u64cd\u4f5c\u4e86\u3002<br \/>\n\u4ece CopyOnWriteArrayList \u7684\u540d\u5b57\u53ef\u4ee5\u770b\u51fa,CopyOnWriteArrayList \u662f\u6ee1\u8db3 CopyOnWrite \u7684 ArrayList,\u6240\u8c13CopyOnWrite\u7684\u610f\u601d\uff1a\u3001\u5c31\u662f\u5bf9\u4e00\u5757\u5185\u5b58\u8fdb\u884c\u4fee\u6539\u65f6\uff0c\u4e0d\u76f4\u63a5\u5728\u539f\u6709\u5185\u5b58\u5757 \u4e2d\u8fdb\u884c\u5199\u64cd\u4f5c\uff0c\u800c\u662f\u5c06\u5185\u5b58\u62f7\u8d1d\u4e00\u4efd\uff0c\u5728\u65b0\u7684\u5185\u5b58\u4e2d\u8fdb\u884c\u5199\u64cd\u4f5c\uff0c\u5199\u5b8c\u4e4b\u540e\uff0c\u518d\u5c06\u539f\u6765\u6307\u5411\u7684\u5185\u5b58\u6307\u9488\u6307\u5230\u65b0\u7684\u5185\u5b58\uff0c\u539f\u6765\u7684\u5185\u5b58\u5c31\u53ef\u4ee5\u88ab\u56de\u6536\u3002<br \/>\nCopyOnWriteArrayList\u8bfb\u53d6\u548c\u5199\u5165\u6e90\u7801\u7b80\u5355\u5206\u6790<br \/>\n1\u3001CopyOnWriteArrayList \u8bfb\u53d6\u64cd\u4f5c\u7684\u5b9e\u73b0<br \/>\n\u8bfb\u53d6\u64cd\u4f5c\u6ca1\u6709\u4efb\u4f55\u540c\u6b65\u63a7\u5236\u548c\u9501\u64cd\u4f5c\uff0c\u7406\u7531\u5c31\u662f\u5185\u90e8\u6570\u7ec4array\u4e0d\u4f1a\u53d1\u751f\u4fee\u6539\uff0c\u53ea\u4f1a\u88ab\u53e6\u5916 \u2014\u4e2aarray\u66ff\u6362\uff0c\u56e0\u6b64\u53ef\u4ee5\u4fdd\u8bc1\u6570\u636e\u5b89\u5168\u3002<br \/>\n\/** The array, accessed only via getArray\/setArray.*\/<br \/>\nprivate transient volatile Object[] array;<br \/>\npublic E get(int index) {<br \/>\nreturn get(getArray(), index);<br \/>\n}<br \/>\n@SuppressWarnings(&quot;unchecked&quot;)<br \/>\nprivate E get(Object[] a, int index) {<br \/>\nreturn (E) a[index];<br \/>\n}<br \/>\nfinal Object[] getArray() {<br \/>\nreturn array;<br \/>\n}<br \/>\n2\u3001CopyOnWriteArrayList \u5199\u5165\u64cd\u4f5c\u7684\u5b9e\u73b0<br \/>\nCopyOnWriteArrayList\u5199\u5165\u64cd\u4f5cadd()\u65b9\u6cd5\u5728\u6dfb\u52a0\u96c6\u5408\u7684\u65f6\u5019\u52a0\u4e86\u9501\uff0c\u4fdd\u8bc1\u540c\u6b65\uff0c\u907f\u514d\u591a\u7ebf \u7a0b\u5199\u7684\u65f6\u5019\u4f1acopy\u51fa\u591a\u4e2a\u526f\u672c\u3002<br \/>\n*Appends the specified element to the end of this list.<br \/>\n*<\/p>\n<ul>\n<li>@param e element to be appended to this list<br \/>\n*@return {@code true} (as specified by {@link Collection#add})<br \/>\n*\/<br \/>\npublic boolean add(E e) {<br \/>\nfinal ReentrantLock lock = this, lock;<br \/>\nlock.lock() ;\t\/\/ \u52a0\u9501<br \/>\ntry {<br \/>\nObject [] elements = get Array();<br \/>\nint len = elements.length;<br \/>\nObject[] newElements = Arrays.copyOf (elements, len + 1) ;\t\/\/ \u62f7\u8d1d\u65b0\u6570\u7ec4<br \/>\nnewElements[len] = e;<br \/>\nsetArray(newElements);<br \/>\nreturn true;<br \/>\n} finally {<br \/>\nlock, unlock() ;\t\/\/ \u91ca\u653e\u9501<br \/>\n}<br \/>\n}<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>CopyOnWriteArrayList\u662f\u4e00\u4e2a\u5e76\u53d1\u5bb9\u5668\u3002\u6709\u5f88\u591a\u4eba\u79f0\u5b83\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u6211\u8ba4\u4e3a\u8fd9\u53e5\u8bdd\u4e0d\u4e25\u8c28\uff0c \u7f3a\u5c11\u4e00 [&hellip;]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[118],"tags":[],"class_list":["post-10216","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10216","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=10216"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10216\/revisions"}],"predecessor-version":[{"id":10218,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10216\/revisions\/10218"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=10216"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=10216"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=10216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}