{"id":457,"date":"2024-09-15T00:03:46","date_gmt":"2024-09-14T16:03:46","guid":{"rendered":"https:\/\/www.ikaros.love\/?p=457"},"modified":"2024-09-15T00:09:12","modified_gmt":"2024-09-14T16:09:12","slug":"java%e7%9a%84%e5%9b%9b%e7%a7%8d%e5%bc%95%e7%94%a8%e6%96%b9%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/www.ikaros.love\/?p=457","title":{"rendered":"JAVA\u7684\u56db\u79cd\u5f15\u7528\u65b9\u5f0f"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"620\" height=\"636\" src=\"https:\/\/www.ikaros.love\/wp-content\/uploads\/2024\/09\/40.png\" alt=\"\" class=\"wp-image-458\" srcset=\"https:\/\/www.ikaros.love\/wp-content\/uploads\/2024\/09\/40.png 620w, https:\/\/www.ikaros.love\/wp-content\/uploads\/2024\/09\/40-292x300.png 292w\" sizes=\"(max-width: 620px) 100vw, 620px\" \/><\/figure>\n\n\n\n<p>java\u5bf9\u8c61\u7684\u5f15\u7528\u5305\u62ec\u5f3a\u5f15\u7528\uff0c\u8f6f\u5f15\u7528\uff0c\u5f31\u5f15\u7528\uff0c\u865a\u5f15\u7528\u3002Java\u4e2d\u63d0\u4f9b\u8fd9\u56db\u79cd\u5f15\u7528\u7c7b\u578b\u4e3b\u8981\u6709\u4e24\u4e2a\u76ee\u7684\uff1a\u4e00\u662f\u53ef\u4ee5\u8ba9\u7a0b\u5e8f\u5458\u901a\u8fc7\u4ee3\u7801\u7684\u65b9\u5f0f\u51b3\u5b9a\u67d0\u4e9b\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\uff1b\u4e8c\u662f\u6709\u5229\u4e8eJVM\u8fdb\u884c\u5783\u573e\u56de\u6536\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u5f3a\u5f15\u7528\"><a href=\"https:\/\/zhulinyin.github.io\/2019\/01\/28\/Java%E7%9A%84%E5%9B%9B%E7%A7%8D%E5%BC%95%E7%94%A8%E6%96%B9%E5%BC%8F\/#%E5%BC%BA%E5%BC%95%E7%94%A8\"><\/a>\u5f3a\u5f15\u7528<\/h3>\n\n\n\n<p>\u5f3a\u5f15\u7528\u662f\u6307\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u5e76\u628a\u8fd9\u4e2a\u5bf9\u8c61\u8d4b\u7ed9\u4e00\u4e2a\u5f15\u7528\u53d8\u91cf\u3002\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Object object =new Object();\nString str =\"hello\";<\/code><\/pre>\n\n\n\n<p>\u5f3a\u5f15\u7528\u6709\u5f15\u7528\u53d8\u91cf\u6307\u5411\u65f6\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u5783\u573e\u56de\u6536\uff0cJVM\u5b81\u613f\u629b\u51faOutOfMemory\u9519\u8bef\u4e5f\u4e0d\u4f1a\u56de\u6536\u8fd9\u79cd\u5bf9\u8c61\u3002\u53ef\u4ee5\u663e\u793a\u5730\u5c06\u5f15\u7528\u8d4b\u503c\u4e3anull\uff0cJVM\u5c31\u4f1a\u5728\u5408\u9002\u7684\u65f6\u95f4\u56de\u6536\u8be5\u5bf9\u8c61\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u8f6f\u5f15\u7528\"><a href=\"https:\/\/zhulinyin.github.io\/2019\/01\/28\/Java%E7%9A%84%E5%9B%9B%E7%A7%8D%E5%BC%95%E7%94%A8%E6%96%B9%E5%BC%8F\/#%E8%BD%AF%E5%BC%95%E7%94%A8\"><\/a>\u8f6f\u5f15\u7528<\/h3>\n\n\n\n<p>\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u5177\u6709\u8f6f\u5f15\u7528\uff0c\u5185\u5b58\u7a7a\u95f4\u8db3\u591f\uff0c\u5783\u573e\u56de\u6536\u5668\u5c31\u4e0d\u4f1a\u56de\u6536\u5b83\uff1b\u5982\u679c\u5185\u5b58\u7a7a\u95f4\u4e0d\u8db3\u4e86\uff0c\u5783\u573e\u6536\u96c6\u7ebf\u7a0b\u4f1a\u5728\u865a\u62df\u673a\u629b\u51faOutOfMemoryError\u4e4b\u524d\u56de\u6536\u8f6f\u53ef\u53ca\u5bf9\u8c61\uff0c\u800c\u4e14<strong>\u865a\u62df\u673a\u4f1a\u5c3d\u53ef\u80fd\u4f18\u5148\u56de\u6536\u957f\u65f6\u95f4\u95f2\u7f6e\u4e0d\u7528\u7684\u8f6f\u53ef\u53ca\u5bf9\u8c61\uff0c\u5bf9\u90a3\u4e9b\u521a\u521a\u6784\u5efa\u7684\u6216\u521a\u521a\u4f7f\u7528\u8fc7\u7684\u201c\u65b0\u201d\u8f6f\u53ef\u53cd\u5bf9\u8c61\u4f1a\u88ab\u865a\u62df\u673a\u5c3d\u53ef\u80fd\u4fdd\u7559<\/strong>\uff08\u8f6f\u5f15\u7528\u6709\u4e24\u4e2a\u7279\u6b8a\u7684\u53d8\u91cf\uff1aclock\u2014\u2014\u8bb0\u5f55\u4e0a\u4e00\u6b21GC\u7684\u65f6\u95f4\uff1btimestamp\u2014\u2014\u8bb0\u5f55\u8be5\u53d8\u91cf\u4e0a\u4e00\u6b21get\u7684\u65f6\u95f4\u3002\u8fd9\u4e24\u4e2a\u53d8\u91cf\u4e4b\u5dee\u8868\u793a<strong>\u8fd9\u4e2a\u8f6f\u5f15\u7528\u5bf9\u8c61\u8ddd\u79bb\u4e0a\u6b21GC\u65f6\u4e00\u76f4\u6ca1\u88ab\u4f7f\u7528\u7684\u65f6\u95f4<\/strong>\uff0c\u5f53\u8fd9\u4e2a\u5dee\u503c\u5927\u4e8e\u9608\u503c_max_interval\uff08\u8be5\u9608\u503c\u7531\u4e0a\u4e00\u6b21GC\u540e\u5269\u4f59\u53ef\u7528\u7a7a\u95f4\u8ba1\u7b97\u5f97\u51fa\uff0c\u7a7a\u95f4\u8d8a\u5927\uff0c\u8be5\u9608\u503c\u8d8a\u5927\uff09\u65f6\uff0c\u5219\u8be5\u5bf9\u8c61\u6807\u8bb0\u4e3a\u53ef\u5e9f\u5f03\u7684\uff0c\u5c06\u5728\u4e0b\u4e00\u6b21GC\u65f6\u56de\u6536\uff09\u3002\u53ea\u8981\u5783\u573e\u56de\u6536\u5668\u6ca1\u6709\u56de\u6536\u5b83\uff0c\u8be5\u5bf9\u8c61\u5c31\u53ef\u4ee5\u88ab\u7a0b\u5e8f\u4f7f\u7528\u3002\u8f6f\u5f15\u7528\u53ef\u7528\u6765\u5b9e\u73b0\u5185\u5b58\u654f\u611f\u7684\u9ad8\u901f\u7f13\u5b58,\u6bd4\u5982\u7f51\u9875\u7f13\u5b58\u3001\u56fe\u7247\u7f13\u5b58\u7b49\u3002\u4f7f\u7528\u8f6f\u5f15\u7528\u80fd\u9632\u6b62\u5185\u5b58\u6cc4\u9732\uff0c\u589e\u5f3a\u7a0b\u5e8f\u7684\u5065\u58ee\u6027\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>MyObject aRef = new MyObject();\nSoftReference aSoftRef=new SoftReference(aRef);\naRef = null;<\/code><\/pre>\n\n\n\n<p>\u5c06MyObject\u5bf9\u8c61\u53d8\u6210\u8f6f\u5f15\u7528\u5bf9\u8c61\uff0c\u5e76\u7ed3\u675f\u5bf9\u8fd9\u4e2a\u5bf9\u8c61\u7684\u5f3a\u5f15\u7528\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>MyObject anotherRef=(MyObject)aSoftRef.get();<\/code><\/pre>\n\n\n\n<p>SoftReference\u4fdd\u5b58\u4e00\u4e2aJava\u5bf9\u8c61\u7684\u8f6f\u5f15\u7528\u540e\uff0c\u5728\u5783\u573e\u7ebf\u7a0b\u5bf9Java\u5bf9\u8c61\u56de\u6536\u524d\uff0c\u53ef\u4ee5\u901a\u8fc7SoftReference\u7c7b\u63d0\u4f9b\u7684get\u65b9\u6cd5\u83b7\u5f97\u8be5Java\u5bf9\u8c61\u7684\u5f3a\u5f15\u7528\u3002\u4f46\u662f\u4e00\u65e6\u5783\u573e\u7ebf\u7a0b\u56de\u6536\u4e86\u8be5Java\u5bf9\u8c61\uff0cget\u65b9\u6cd5\u8fd4\u56denull\u3002<\/p>\n\n\n\n<p>\u4f5c\u4e3a\u4e00\u4e2aJava\u5bf9\u8c61\uff0cSoftReference\u5bf9\u8c61\u9664\u4e86\u5177\u6709\u4fdd\u5b58\u8f6f\u5f15\u7528\u7684\u7279\u6b8a\u6027\u4e4b\u5916\uff0c\u4e5f\u5177\u6709Java\u5bf9\u8c61\u7684\u4e00\u822c\u6027\u3002\u6240\u4ee5\u5f53\u8f6f\u53ef\u53ca\u5bf9\u8c61\u88ab\u56de\u6536\u4e4b\u540e\uff0c\u8fd9\u4e2aSoftReference\u5bf9\u8c61\u5df2\u7ecf\u4e0d\u518d\u5177\u6709\u5b58\u5728\u7684\u4ef7\u503c\uff0c\u9700\u8981\u4e00\u4e2a\u9002\u5f53\u7684\u6e05\u9664\u673a\u5236\uff0c\u907f\u514d\u5927\u91cfSoftReference\u5bf9\u8c61\u5e26\u6765\u7684\u5185\u5b58\u6cc4\u6f0f\u3002\u5728java.lang.ref\u5305\u91cc\u8fd8\u63d0\u4f9b\u4e86ReferenceQueue\u3002\u5982\u679c\u5728\u521b\u5efaSoftReference\u5bf9\u8c61\u7684\u65f6\u5019\uff0c\u4f7f\u7528\u4e86\u4e00\u4e2aReferenceQueue\u5bf9\u8c61\u4f5c\u4e3a\u53c2\u6570\u63d0\u4f9b\u7ed9SoftReference\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u5982:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ReferenceQueue queue = new ReferenceQueue();\nSoftReference ref=new SoftReference(aMyObject, queue);<\/code><\/pre>\n\n\n\n<p>\u5f53\u8fd9\u4e2aSoftReference\u6240\u8f6f\u5f15\u7528\u7684aMyOhject\u88ab\u5783\u573e\u6536\u96c6\u5668\u56de\u6536\u7684\u540c\u65f6\uff0cref\u6240\u5f3a\u5f15\u7528\u7684SoftReference\u5bf9\u8c61\u88ab\u5217\u5165ReferenceQueue\u3002\u4e5f\u5c31\u662f\u8bf4\uff0cReferenceQueue\u4e2d\u4fdd\u5b58\u7684\u5bf9\u8c61\u662fReference\u5bf9\u8c61\uff0c\u800c\u4e14\u662f\u5df2\u7ecf\u5931\u53bb\u4e86\u5b83\u6240\u8f6f\u5f15\u7528\u7684\u5bf9\u8c61\u7684Reference\u5bf9\u8c61\u3002\u53e6\u5916\u4eceReferenceQueue\u8fd9\u4e2a\u540d\u5b57\u4e5f\u53ef\u4ee5\u770b\u51fa\uff0c\u5b83\u662f\u4e00\u4e2a\u961f\u5217\uff0c\u5f53\u6211\u4eec\u8c03\u7528\u5b83\u7684poll()\u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u5982\u679c\u8fd9\u4e2a\u961f\u5217\u4e2d\u4e0d\u662f\u7a7a\u961f\u5217\uff0c\u90a3\u4e48\u5c06\u8fd4\u56de\u961f\u5217\u524d\u9762\u7684\u90a3\u4e2aReference\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p>\u5728\u4efb\u4f55\u65f6\u5019\uff0c\u6211\u4eec\u90fd\u53ef\u4ee5\u8c03\u7528ReferenceQueue\u7684poll()\u65b9\u6cd5\u6765\u68c0\u67e5\u662f\u5426\u6709\u5b83\u6240\u5173\u5fc3\u7684\u975e\u5f3a\u53ef\u53ca\u5bf9\u8c61\u88ab\u56de\u6536\u3002\u5982\u679c\u961f\u5217\u4e3a\u7a7a\uff0c\u5c06\u8fd4\u56de\u4e00\u4e2anull,\u5426\u5219\u8be5\u65b9\u6cd5\u8fd4\u56de\u961f\u5217\u4e2d\u524d\u9762\u7684\u4e00\u4e2aReference\u5bf9\u8c61\u3002\u5229\u7528\u8fd9\u4e2a\u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u68c0\u67e5\u54ea\u4e2aSoftReference\u6240\u8f6f\u5f15\u7528\u7684\u5bf9\u8c61\u5df2\u7ecf\u88ab\u56de\u6536\u3002\u4e8e\u662f\u6211\u4eec\u53ef\u4ee5\u628a\u8fd9\u4e9b\u5931\u53bb\u6240\u8f6f\u5f15\u7528\u7684\u5bf9\u8c61\u7684SoftReference\u5bf9\u8c61\u6e05\u9664\u6389\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u5f31\u5f15\u7528\"><a href=\"https:\/\/zhulinyin.github.io\/2019\/01\/28\/Java%E7%9A%84%E5%9B%9B%E7%A7%8D%E5%BC%95%E7%94%A8%E6%96%B9%E5%BC%8F\/#%E5%BC%B1%E5%BC%95%E7%94%A8\"><\/a>\u5f31\u5f15\u7528<\/h3>\n\n\n\n<p>\u5f31\u5f15\u7528\u4e5f\u662f\u7528\u6765\u63cf\u8ff0\u975e\u5fc5\u9700\u5bf9\u8c61\u7684\uff0c\u5f53JVM\u8fdb\u884c\u5783\u573e\u56de\u6536\u65f6\uff0c\u65e0\u8bba\u5185\u5b58\u662f\u5426\u5145\u8db3\uff0c\u90fd\u4f1a\u56de\u6536\u88ab\u5f31\u5f15\u7528\u5173\u8054\u7684\u5bf9\u8c61\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public static void main(String&#91;] args) {\n  WeakReference&lt;People>reference=new WeakReference&lt;People>(new People(\"zhouqian\",20));\n  System.out.println(reference.get());\n  System.gc();\n  System.out.println(reference.get());\n}<\/code><\/pre>\n\n\n\n<p>\u7b2c\u4e8c\u4e2a\u8f93\u51fa\u7ed3\u679c\u662fnull\uff0c\u8fd9\u8bf4\u660e\u53ea\u8981JVM\u8fdb\u884c\u5783\u573e\u56de\u6536\uff0c\u88ab\u5f31\u5f15\u7528\u5173\u8054\u7684\u5bf9\u8c61\u5fc5\u5b9a\u4f1a\u88ab\u56de\u6536\u6389\u3002\u4e0d\u8fc7\u8981\u6ce8\u610f\u7684\u662f\uff0c\u8fd9\u91cc\u6240\u8bf4\u7684\u88ab\u5f31\u5f15\u7528\u5173\u8054\u7684\u5bf9\u8c61\u662f\u6307\u53ea\u6709\u5f31\u5f15\u7528\u4e0e\u4e4b\u5173\u8054\uff0c\u5982\u679c\u5b58\u5728\u5f3a\u5f15\u7528\u540c\u65f6\u4e0e\u4e4b\u5173\u8054\uff0c\u5219\u8fdb\u884c\u5783\u573e\u56de\u6536\u65f6\u4e5f\u4e0d\u4f1a\u56de\u6536\u8be5\u5bf9\u8c61\uff08\u8f6f\u5f15\u7528\u4e5f\u662f\u5982\u6b64\uff09\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public static void main(String&#91;] args) {\n  People people=new People(\"zhouqian\",20);\n  WeakReference&lt;People&gt;reference=new WeakReference&lt;People&gt;(people);\n  System.out.println(reference.get());\n  System.gc();\n  System.out.println(reference.get());\n}<\/code><\/pre>\n\n\n\n<p>\u4e24\u4e2a\u8f93\u51fa\u7ed3\u679c\u76f8\u540c\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u865a\u5f15\u7528\"><a href=\"https:\/\/zhulinyin.github.io\/2019\/01\/28\/Java%E7%9A%84%E5%9B%9B%E7%A7%8D%E5%BC%95%E7%94%A8%E6%96%B9%E5%BC%8F\/#%E8%99%9A%E5%BC%95%E7%94%A8\"><\/a>\u865a\u5f15\u7528<\/h3>\n\n\n\n<p>\u865a\u5f15\u7528\u548c\u524d\u9762\u7684\u8f6f\u5f15\u7528\u3001\u5f31\u5f15\u7528\u4e0d\u540c\uff0c\u5b83\u5e76\u4e0d\u5f71\u54cd\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\u3002\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u4e0e\u865a\u5f15\u7528\u5173\u8054\uff0c\u5219\u8ddf\u6ca1\u6709\u5f15\u7528\u4e0e\u4e4b\u5173\u8054\u4e00\u6837\uff0c\u5728\u4efb\u4f55\u65f6\u5019\u90fd\u53ef\u80fd\u88ab\u5783\u573e\u56de\u6536\u5668\u56de\u6536\u3002&nbsp;<strong>\u4e3a\u4e00\u4e2a\u5bf9\u8c61\u8bbe\u7f6e\u865a\u5f15\u7528\u5173\u8054\u7684\u552f\u4e00\u76ee\u7684\u5c31\u662f\u80fd\u5728\u8fd9\u4e2a\u5bf9\u8c61\u88ab\u6536\u96c6\u5668\u56de\u6536\u65f6\u6536\u5230\u4e00\u4e2a\u7cfb\u7edf\u901a\u77e5\u3002<\/strong>&nbsp;\u865a\u5f15\u7528\u5fc5\u987b\u548c\u5f15\u7528\u961f\u5217\u5173\u8054\u4f7f\u7528\uff0c\u5f53\u5783\u573e\u56de\u6536\u5668\u51c6\u5907\u56de\u6536\u4e00\u4e2a\u5bf9\u8c61\u65f6\uff0c\u5982\u679c\u53d1\u73b0\u5b83\u8fd8\u6709\u865a\u5f15\u7528\uff0c\u5c31\u4f1a\u628a\u8fd9\u4e2a\u865a\u5f15\u7528\u52a0\u5165\u5230\u4e0e\u4e4b\u5173\u8054\u7684\u5f15\u7528\u961f\u5217\u4e2d\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public static void main(String&#91;] args) {\n  ReferenceQueue&lt;String> queue = new ReferenceQueue&lt;String>();\n  PhantomReference&lt;String> pr = new PhantomReference&lt;String>(new String(\"hello\"), queue);\n  System.out.println(pr.get());\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>java\u5bf9\u8c61\u7684\u5f15\u7528\u5305\u62ec\u5f3a\u5f15\u7528\uff0c\u8f6f&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":458,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[147,149],"_links":{"self":[{"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/posts\/457"}],"collection":[{"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=457"}],"version-history":[{"count":4,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/posts\/457\/revisions"}],"predecessor-version":[{"id":463,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/posts\/457\/revisions\/463"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=\/wp\/v2\/media\/458"}],"wp:attachment":[{"href":"https:\/\/www.ikaros.love\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=457"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=457"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ikaros.love\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}