{"id":283,"date":"2024-10-04T12:04:51","date_gmt":"2024-10-04T04:04:51","guid":{"rendered":"https:\/\/www.zackzzp.top\/?p=283"},"modified":"2024-10-04T12:05:52","modified_gmt":"2024-10-04T04:05:52","slug":"java%e4%b8%ad%e7%9a%84%e5%9b%9b%e7%a7%8d%e5%bc%95%e7%94%a8","status":"publish","type":"post","link":"http:\/\/www.zackzzp.top\/index.php\/2024\/10\/04\/java%e4%b8%ad%e7%9a%84%e5%9b%9b%e7%a7%8d%e5%bc%95%e7%94%a8\/","title":{"rendered":"JAVA\u4e2d\u7684\u56db\u79cd\u5f15\u7528"},"content":{"rendered":"

\u6982\u8ff0<\/h2>\n

\u5728 Java \u4e2d\uff0c\u5bf9\u8c61\u7684\u5f15\u7528\u7c7b\u578b\u5bf9\u4e8e\u7406\u89e3\u5982\u4f55\u5f15\u7528\u5bf9\u8c61\u4ee5\u53ca\u5bf9\u8c61\u5982\u4f55\u4e0e\u5783\u573e\u56de\u6536\u5668(GC)\u4e00\u8d77\u5de5\u4f5c\u975e\u5e38\u91cd\u8981\u3002Java \u63d0\u4f9b\u4e86\u56db\u79cd\u4e0d\u540c\u7684\u5f15\u7528\u7c7b\u578b\uff1a\u5f3a\u5f15\u7528(Strong Reference)\u3001\u8f6f\u5f15\u7528(Soft Reference)\u3001\u5f31\u5f15\u7528(Weak Reference)\u548c\u865a\u5f15\u7528(Phantom Reference)\u3002\u4e0b\u9762\uff0c\u6211\u4eec\u5c06\u63a2\u8ba8\u6bcf\u79cd\u7c7b\u578b\u7684\u7279\u70b9\uff0c\u5e76\u901a\u8fc7\u4ee3\u7801\u793a\u4f8b\u6f14\u793a\u5b83\u4eec\u7684\u4f7f\u7528\u3002<\/p>\n

\n

\u5f3a\u5f15\u7528<\/h2>\n

\u5f3a\u5f15\u7528\u662f\u6700\u5e38\u89c1\u7684\u5f15\u7528\u7c7b\u578b\uff0c\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u5177\u6709\u5f3a\u5f15\u7528\uff0c\u90a3\u4e48\u5b83\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u5783\u573e\u56de\u6536\u5668\u56de\u6536\uff0c\u5373\u4f7f\u8fd9\u4e2a\u5bf9\u8c61\u4ee5\u540e\u4e0d\u518d\u9700\u8981\u4e86\uff0c\u4e5f\u53ef\u80fd\u5bfc\u81f4\u5185\u5b58\u6cc4\u6f0f\u3002<\/p>\n

\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n

Object obj = new Object(); \/\/ \u521b\u5efa\u4e00\u4e2a\u5f3a\u5f15\u7528

\u53ea\u8981 obj \u5f15\u7528\u5b58\u5728\uff0c\u8fd9\u4e2a\u65b0\u521b\u5efa\u7684\u5bf9\u8c61\u5c31\u4e0d\u4f1a\u88ab\u5783\u573e\u56de\u6536\uff0c\u76f4\u5230 obj \u5207\u6362\u5176\u4ed6\u5f15\u7528\u6216\u8005\u4e3anull\u3002<\/p>\n

\n

\u8f6f\u5f15\u7528<\/h2>\n

\u8f6f\u5f15\u7528\u662f\u7528\u6765\u63cf\u8ff0\u4e00\u4e9b\u8fd8\u6709\u7528\u4f46\u5e76\u975e\u5fc5\u9700\u7684\u5bf9\u8c61\u3002\u5728 JVM \u5c06\u8981\u629b\u51fa\u5185\u5b58\u6ea2\u51fa\u5f02\u5e38\u4e4b\u524d\uff0c\u4f1a\u628a\u8fd9\u4e9b\u5bf9\u8c61\u5217\u5165\u56de\u6536\u8303\u56f4\u8fdb\u884c\u7b2c\u4e8c\u6b21\u56de\u6536\u3002\u5982\u679c\u8fd8\u662f\u6ca1\u6709\u8db3\u591f\u7684\u5185\u5b58\uff0c\u624d\u4f1a\u629b\u51fa\u5185\u5b58\u6ea2\u51fa\u5f02\u5e38\u3002<\/p>\n

\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n

import java.lang.ref.SoftReference;<\/p>\n

Object obj = new Object();
SoftReference<Object> softRef = new SoftReference<>(obj);
obj = null; \/\/\u53d6\u6d88\u5f3a\u5f15\u7528<\/p>\n

\/\/\u53ef\u4ee5\u901a\u8fc7 softRef.get() \u5f97\u5230 obj \u5bf9\u8c61\uff0c\u5f53\u5185\u5b58\u8db3\u591f\u65f6\u4e0d\u4f1a\u56de\u6536 softRef \u6307\u5411\u7684\u5bf9\u8c61\u3002
Object obj2 = softRef.get();

\u5982\u679c obj2 \u4e3a null\uff0c\u8868\u793a\u5bf9\u8c61\u5df2\u88ab\u5783\u573e\u56de\u6536\u3002<\/p>\n

\n

\u5f31\u5f15\u7528<\/h2>\n

\u5f31\u5f15\u7528\u4e0d\u50cf\u8f6f\u5f15\u7528\u90a3\u4e48\u5f3a\u5927\uff0c\u5b83\u7528\u6765\u63cf\u8ff0\u975e\u5fc5\u9700\u5bf9\u8c61\uff0c\u4f46\u662f\u5176\u5f3a\u5ea6\u6bd4\u8f6f\u5f15\u7528\u66f4\u5f31\uff0c\u88ab\u5f31\u5f15\u7528\u5173\u8054\u7684\u5bf9\u8c61\u53ea\u80fd\u751f\u5b58\u5230\u4e0b\u4e00\u6b21\u5783\u573e\u56de\u6536\u4e4b\u524d\u3002<\/p>\n

\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n

import java.lang.ref.WeakReference;<\/p>\n

Object obj = new Object();
WeakReference<Object> weakRef = new WeakReference<>(obj);
obj = null; \/\/\u53d6\u6d88\u5f3a\u5f15\u7528<\/p>\n

\/\/\u5f53 GC \u53d1\u751f\u65f6\uff0c\u65e0\u8bba\u5185\u5b58\u662f\u5426\u8db3\u5921\uff0c\u53ea\u8981\u53d1\u73b0\u5f31\u5f15\u7528\uff0c\u90fd\u4f1a\u56de\u6536\u5176\u5bf9\u8c61\u3002
Object obj2 = weakRef.get();

obj2 \u53ef\u80fd\u4e3a null\uff0c\u5982\u679c\u5bf9\u8c61\u5df2\u88ab\u56de\u6536\u3002<\/p>\n

\n

\u865a\u5f15\u7528<\/h2>\n

\u865a\u5f15\u7528\u662f\u6700\u5f31\u7684\u4e00\u79cd\u5f15\u7528\u5173\u7cfb\uff0c\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u6709\u865a\u5f15\u7528\u7684\u5b58\u5728\uff0c\u5b8c\u5168\u4e0d\u4f1a\u5bf9\u5176\u751f\u5b58\u65f6\u95f4\u6784\u6210\u5f71\u54cd\uff0c\u4e5f\u65e0\u6cd5\u901a\u8fc7\u865a\u5f15\u7528\u6765\u53d6\u5f97\u4e00\u4e2a\u5bf9\u8c61\u5b9e\u4f8b\u3002<\/p>\n

\u865a\u5f15\u7528\u5e76\u4e0d\u76f4\u63a5\u51b3\u5b9a\u5bf9\u8c61\u7684\u56de\u6536\u65f6\u673a\uff0c\u800c\u662f\u63d0\u4f9b\u4e86\u4e00\u79cd\u673a\u5236\uff0c\u5141\u8bb8\u7a0b\u5e8f\u5458\u5728\u5bf9\u8c61\u88ab\u56de\u6536\u65f6\u5f97\u5230\u901a\u77e5\uff0c\u4ee5\u4fbf\u6267\u884c\u8fdb\u4e00\u6b65\u7684\u6e05\u7406\u5de5\u4f5c\u3002<\/p>\n

\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n

import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;<\/p>\n

Object obj = new Object();
ReferenceQueue<Object> refQueue = new ReferenceQueue<>();
PhantomReference<Object> phantomRef = new PhantomReference<>(obj, refQueue);
obj = null; \/\/\u53d6\u6d88\u5f3a\u5f15\u7528<\/p>\n

\/\/\u865a\u5f15\u7528\u901a\u5e38\u7528\u4e8e\u5728\u5bf9\u8c61\u88ab\u56de\u6536\u65f6\u6536\u5230\u4e00\u4e2a\u7cfb\u7edf\u901a\u77e5\u3002

\u7531\u4e8e\u65e0\u6cd5\u901a\u8fc7\u865a\u5f15\u7528\u83b7\u53d6\u5bf9\u8c61\uff0c\u5b83\u5e38\u7528\u4e8e\u7ba1\u7406\u76f4\u63a5\u5185\u5b58\u3002<\/p>\n

\n

\u603b\u7ed3<\/h2>\n

\u5728 Java \u4e2d\uff0c\u6b63\u786e\u4f7f\u7528\u5404\u79cd\u5f15\u7528\u7c7b\u578b\u53ef\u4ee5\u4f18\u5316\u5185\u5b58\u4f7f\u7528\uff0c\u907f\u514d\u5185\u5b58\u6ea2\u51fa\uff0c\u5e76\u53ef\u4ee5\u66f4\u7ec6\u7c92\u5ea6\u5730\u63a7\u5236\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\u3002\u5f3a\u5f15\u7528\u662f\u9ed8\u8ba4\u884c\u4e3a\uff0c\u4f46\u5728\u6709\u7279\u5b9a\u5185\u5b58\u7ba1\u7406\u9700\u6c42\u7684\u573a\u5408\uff0c\u4f7f\u7528\u8f6f\u5f15\u7528\u3001\u5f31\u5f15\u7528\u548c\u865a\u5f15\u7528\u53ef\u4ee5\u66f4\u597d\u5730\u4e0e\u5783\u573e\u56de\u6536\u5668\u534f\u4f5c\uff0c\u51cf\u5c11\u5185\u5b58\u6cc4\u6f0f\u7684\u98ce\u9669\u3002<\/p>\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

\u6982\u8ff0 \u5728 Java \u4e2d\uff0c\u5bf9\u8c61\u7684\u5f15\u7528\u7c7b\u578b\u5bf9\u4e8e\u7406\u89e3\u5982\u4f55\u5f15\u7528\u5bf9\u8c61\u4ee5\u53ca\u5bf9\u8c61\u5982\u4f55\u4e0e\u5783\u573e\u56de\u6536\u5668(GC)\u4e00\u8d77\u5de5\u4f5c\u975e\u5e38\u91cd\u8981\u3002J […]<\/p>\n","protected":false},"author":1,"featured_media":285,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-283","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/posts\/283","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/comments?post=283"}],"version-history":[{"count":2,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/posts\/283\/revisions"}],"predecessor-version":[{"id":284,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/posts\/283\/revisions\/284"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/media\/285"}],"wp:attachment":[{"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/media?parent=283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/categories?post=283"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.zackzzp.top\/index.php\/wp-json\/wp\/v2\/tags?post=283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}