{"id":1368,"date":"2019-08-17T18:01:21","date_gmt":"2019-08-17T10:01:21","guid":{"rendered":"http:\/\/www.sniper97.cn\/?p=1368"},"modified":"2019-08-17T18:01:21","modified_gmt":"2019-08-17T10:01:21","slug":"%e3%80%90java%e8%99%9a%e6%8b%9f%e6%9c%ba%e3%80%91java%e5%86%85%e5%ad%98%e5%8c%ba%e5%9f%9f%e4%b8%8e%e5%86%85%e5%ad%98%e6%ba%a2%e5%87%ba%e5%bc%82%e5%b8%b8","status":"publish","type":"post","link":"http:\/\/www.sniper97.cn\/index.php\/note\/jvm\/1368\/","title":{"rendered":"\u3010Java\u865a\u62df\u673a\u3011Java\u5185\u5b58\u533a\u57df\u4e0e\u5185\u5b58\u6ea2\u51fa\u5f02\u5e38"},"content":{"rendered":"\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"354\" height=\"444\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-12.png\" alt=\"\" class=\"wp-image-1378\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-12.png 354w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-12-239x300.png 239w\" sizes=\"(max-width: 354px) 100vw, 354px\" \/><\/figure><\/div>\n\n\n<h2 class=\"wp-block-heading\">1 \u6982\u8ff0<\/h2>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"552\" height=\"390\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-7.png\" alt=\"\" class=\"wp-image-1369\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-7.png 552w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-7-300x212.png 300w\" sizes=\"(max-width: 552px) 100vw, 552px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">1.1 \u7a0b\u5e8f\u8ba1\u6570\u5668\uff08\u7ebf\u7a0b\u79c1\u6709\uff09<\/h3>\n\n\n<p>\u7a0b\u5e8f\u8ba1\u6570\u5668\uff08Program Count Register\uff09\u662f\u4e00\u5757\u8f83\u5c0f\u7684\u5185\u5b58\u7a7a\u95f4\uff0c\u5b83\u53ef\u4ee5\u770b\u4f5c\u662f\u5f53\u524d\u7ebf\u7a0b\u6240\u6267\u884c\u7684\u5b57\u8282\u7801\u884c\u53f7\u7684\u6307\u793a\u5668\u3002<\/p>\n\n\n<p>\u5982\u679c\u7ebf\u7a0b\u6b63\u5728\u6267\u884c\u7684\u662f\u4e00\u4e2aJava\u65b9\u6cd5\uff0c\u8fd9\u4e2a\u8ba1\u6570\u5668\u8bb0\u5f55\u7684\u662f\u6b63\u5728\u6267\u884c\u7684\u865a\u62df\u673a\u5b57\u8282\u7801\u6307\u4ee4\u7684\u5730\u5740\uff1b\u5982\u679c\u6b63\u5728\u6267\u884c\u7684\u662fNative\u65b9\u6cd5\uff0c\u8fd9\u4e2a\u8ba1\u6570\u5668\u503c\u5219\u4e3a\u7a7a\uff08Undefined\uff09\u3002\u6b64\u5185\u5b58\u533a\u57df\u662f\u552f\u4e00\u4e00\u4e2a\u5728Java\u865a\u62df\u673a\u89c4\u8303\u4e2d\u6ca1\u6709\u89c4\u5b9a\u4efb\u4f55OutOfMemoryError\u60c5\u51b5\u7684\u533a\u57df\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.2 Java\u865a\u62df\u673a\u6808\uff08\u7ebf\u7a0b\u79c1\u6709\uff09<\/h3>\n\n\n<p>Java\u865a\u62df\u673a\u6808\uff08Java Virtual Machine Stacks\uff09\u4e5f\u662f\u7ebf\u7a0b\u79c1\u6709\u7684\u3002\u5b83\u7684\u751f\u547d\u5468\u671f\u4e0e\u7ebf\u7a0b\u76f8\u540c\u3002\u6bcf\u4e2a\u65b9\u6cd5\u5728\u6267\u884c\u7684\u540c\u65f6\u90fd\u4f1a\u521b\u5efa\u4e00\u4e2a\u6808\u5e27\uff08Stack Frame\uff09\u7528\u4e8e\u5b58\u50a8\u5c40\u90e8\u53d8\u91cf\u8868\u3001\u64cd\u4f5c\u6570\u6808\u3001\u52a8\u6001\u94fe\u63a5\u3001\u65b9\u6cd5\u51fa\u53e3\u7b49\u4fe1\u606f\u3002<\/p>\n\n\n<p>\u6211\u4eec\u5e38\u8bf4\u7684\u201c\u6808\u201d\u6307\u7684\u5c31\u662fJava\u865a\u62df\u673a\u6808\uff0c\u6216\u8005\u8bf4\u662f\u865a\u62df\u673a\u6808\u4e2d\u5c40\u90e8\u53d8\u91cf\u8868\u7684\u90e8\u5206\u3002<\/p>\n\n\n<p>\u5c40\u90e8\u53d8\u91cf\u8868\u5b58\u653e\u4e86\u7f16\u8bd1\u671f\u53ef\u77e5\u7684\u5404\u79cd\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08boolean\u3001byte\u3001char\u3001short\u3001int\u3001float\u3001long\u3001double\uff09\u3001\u5bf9\u8c61\u5f15\u7528\uff08reference\u7c7b\u578b\uff0c\u5b83\u672c\u8eab\u4e0d\u7b49\u540c\u4e8e\u5bf9\u8c61\u672c\u8eab\uff0c\u53ef\u80fd\u662f\u4e00\u4e2a\u6307\u5411\u5bf9\u8c61\u8d77\u59cb\u5730\u5740\u7684\u5f15\u7528\u6307\u9488\u7b49\uff09\u3001returnAddress\u7c7b\u578b\uff08\u6307\u5411\u4e86\u4e00\u6761\u5b57\u8282\u7801\u6307\u4ee4\u7684\u5730\u5740\uff09\u3002<\/p>\n\n\n<p>\u5c40\u90e8\u53d8\u91cf\u8868\u6240\u9700\u7684\u5185\u5b58\u7a7a\u95f4\u5728\u7f16\u8bd1\u671f\u95f4\u5b8c\u6210\u5206\u914d\uff0c\u5728\u65b9\u6cd5\u8fd0\u884c\u671f\u95f4\u4e0d\u4f1a\u6539\u53d8\u5c40\u90e8\u53d8\u91cf\u8868\u7684\u5927\u5c0f\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.3 \u672c\u5730\u65b9\u6cd5\u6808\uff08\u7ebf\u7a0b\u79c1\u6709\uff09<\/h3>\n\n\n<p>\u672c\u5730\u65b9\u6cd5\u6808\uff08Native Method Stack\uff09\u4e0e\u865a\u62df\u673a\u6808\u6240\u53d1\u6325\u7684\u4f5c\u7528\u662f\u975e\u5e38\u7c7b\u4f3c\u7684\uff0c\u751a\u81f3\u6709\u7684\u865a\u62df\u673a\uff08\u4f8b\u5982Sun HotSpot\u865a\u62df\u673a\uff09\u76f4\u63a5\u5c31\u628a\u672c\u5730\u65b9\u6cd5\u6808\u548c\u865a\u62df\u673a\u6808\u5408\u4e8c\u4e3a\u4e00\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.4 Java\u5806\uff08\u7ebf\u7a0b\u5171\u4eab\uff09<\/h3>\n\n\n<p>Java\u5806\uff08Java Heap\uff09\u662f\u88ab\u6240\u6709\u7ebf\u7a0b\u5171\u4eab\u7684\u4e00\u5757\u5185\u5b58\u533a\u57df\uff0c\u5728\u865a\u62df\u673a\u542f\u52a8\u65f6\u521b\u5efa\u3002\u6b64\u5185\u5b58\u533a\u57df\u7684\u552f\u4e00\u76ee\u7684\u5c31\u662f\u5b58\u653e\u5bf9\u8c61\u7684\u5b9e\u4f8b\uff0c\u51e0\u4e4e\u6240\u6709\u7684\u5bf9\u8c61\u5b9e\u4f8b\u90fd\u5728\u8fd9\u91cc\u8fdb\u884c\u5206\u914d\u3002<\/p>\n\n\n<p>Java\u5806\u53ef\u4ee5\u5904\u4e8e\u7269\u7406\u4e0a\u4e0d\u8fde\u7eed\u7684\u5185\u5b58\u7a7a\u95f4\u4e2d\uff0c\u53ea\u8981\u903b\u8f91\u4e0a\u662f\u8fde\u7eed\u7684\u5373\u53ef\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.5 \u65b9\u6cd5\u533a\uff08\u7ebf\u7a0b\u5171\u4eab\uff09<\/h3>\n\n\n<p>\u65b9\u6cd5\u533a\uff08Method Area\uff09\u4e0eJava\u5806\u4e00\u6837\uff0c\u662f\u5404\u4e2a\u7ebf\u7a0b\u5171\u4eab\u7684\u5185\u5b58\u533a\u57df\uff0c\u5b83\u7528\u4e8e\u5b58\u50a8\u5df2\u88ab\u865a\u62df\u673a\u52a0\u8f7d\u7684\u7c7b\u4fe1\u606f\u3001\u5e38\u91cf\u3001\u9759\u6001\u53d8\u91cf\u3001\u5373\u65f6\u7f16\u8bd1\u5668\u7f16\u8bd1\u540e\u7684\u4ee3\u7801\u7b49\u6570\u636e\u3002<\/p>\n\n\n<p>Java\u865a\u62df\u673a\u89c4\u8303\u5bf9\u65b9\u6cd5\u533a\u7684\u9650\u5236\u975e\u5e38\u5bbd\u677e\uff0c\u9664\u4e86\u548cJava\u5806\u4e00\u6837\u4e0d\u9700\u8981\u8fde\u7eed\u7684\u5185\u5b58\u548c\u53ef\u4ee5\u9009\u62e9\u56fa\u5b9a\u5927\u5c0f\u6216\u8005\u53ef\u6269\u5c55\u5916\uff0c\u8fd8\u53ef\u4ee5\u9009\u62e9\u4e0d\u5b9e\u73b0\u5783\u573e\u6536\u96c6\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">1.6 \u8fd0\u884c\u65f6\u5e38\u91cf\u6c60\uff08\u7ebf\u7a0b\u5171\u4eab\uff09<\/h3>\n\n\n<p>\u8fd0\u884c\u65f6\u5e38\u91cf\u6c60\uff08Runtime Constant Pool\uff09\u662f\u65b9\u6cd5\u533a\u7684\u4e00\u90e8\u5206\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">2.\u5bf9\u8c61<\/h2>\n\n\n<h3 class=\"wp-block-heading\">2.1 \u5bf9\u8c61\u7684\u521b\u5efa<\/h3>\n\n\n<p>1.\u865a\u62df\u673a\u9047\u5230\u4e00\u6761new\u6307\u4ee4\u65f6\uff0c\u9996\u5148\u5c06\u53bb\u68c0\u67e5\u8fd9\u4e2a\u6307\u4ee4\u7684\u53c2\u6570\u662f\u5426\u80fd\u5728\u5e38\u91cf\u6c60\u4e2d\u5b9a\u4f4d\u5230\u4e00\u4e2a\u7c7b\u7684\u7b26\u53f7\u5f15\u7528\uff0c\u5e76\u4e14\u68c0\u67e5\u8fd9\u4e2a\u7b26\u53f7\u5f15\u7528\u4ee3\u8868\u7684\u7c7b\u662f\u5426\u5df2\u88ab\u52a0\u8f7d\u3001\u89e3\u6790\u548c\u521d\u59cb\u5316\u8fc7\u3002\u5982\u679c\u6ca1\u6709\uff0c\u90a3\u5fc5\u987b\u5148\u6267\u884c\u76f8\u5e94\u7684\u7c7b\u52a0\u8f7d\u8fc7\u7a0b\u3002<\/p>\n\n\n<p>2.\u5728\u7c7b\u52a0\u8f7d\u901a\u8fc7\u68c0\u67e5\u540e\uff0c\u63a5\u4e0b\u6765\u865a\u62df\u673a\u5c06\u4e3a\u65b0\u751f\u5bf9\u8c61\u5206\u7c7b\u5185\u5b58\u3002<\/p>\n\n\n<p>\u4e3a\u5bf9\u8c61\u5206\u914d\u7a7a\u95f4\u7684\u4efb\u52a1\u7b49\u540c\u4e8e\u628a\u4e00\u5757\u786e\u5b9a\u5927\u5c0f\u7684\u5185\u5b58\u4eceJava\u5806\u4e2d\u5212\u5206\u51fa\u6765\u3002\u5047\u8bbeJava\u5806\u4e2d\u5185\u5b58\u662f\u7edd\u5bf9\u89c4\u6574\u7684\u6240\u6709\u7528\u8fc7\u7684\u5185\u5b58\u90fd\u653e\u5728\u4e00\u8fb9\uff0c\u7a7a\u95f2\u7684\u5185\u5b58\u653e\u5728\u53e6\u4e00\u8fb9\uff0c\u4e2d\u95f4\u653e\u7740\u4e00\u4e2a\u6307\u9488\u4f5c\u4e3a\u5206\u754c\u70b9\u7684\u6307\u793a\u5668\uff0c\u54ea\u6240\u5206\u914d\u7684\u5185\u5b58\u5c31\u4ec5\u4ec5\u662f\u628a\u90a3\u4e2a\u6307\u9488\u5411\u7a7a\u95f2\u7a7a\u95f4\u90a3\u8fb9\u632a\u52a8\u4e00\u6bb5\u4e0e\u5bf9\u8c61\u5927\u5c0f\u76f8\u540c\u7684\u8ddd\u79bb\uff0c\u8fd9\u79cd\u5206\u914d\u65b9\u5f0f\u79f0\u4e3a\u201c\u6307\u9488\u78b0\u649e\u201d\uff08Bump the Point\uff09\u3002<\/p>\n\n\n<p>\u5982\u679cJava\u5806\u4e2d\u7684\u5185\u5b58\u5e76\u4e0d\u662f\u89c4\u6574\u7684\uff0c\u5df2\u4f7f\u7528\u7684\u5185\u5b58\u548c\u7a7a\u95f2\u7684\u5185\u5b58\u76f8\u4e92\u4ea4\u9519\uff0c\u90a3\u5c31\u6ca1\u6709\u529e\u6cd5\u7b80\u5355\u5730\u8fdb\u884c\u6307\u9488\u78b0\u649e\u4e86\u3002\u865a\u62df\u673a\u5c31\u5fc5\u987b\u7ef4\u62a4\u4e00\u4e2a\u5217\u8868\uff0c\u8bb0\u5f55\u4e0a\u54ea\u4e9b\u5185\u5b58\u5757\u662f\u53ef\u7528\u7684\uff0c\u5728\u5206\u914d\u7684\u65f6\u5019\u4ece\u5217\u8868\u4e2d\u627e\u5230\u4e00\u5757\u8db3\u591f\u5927\u7684\u7a7a\u95f4\u5212\u5206\u7ed9\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u5e76\u66f4\u65b0\u5217\u8868\u4e0a\u7684\u8bb0\u5f55\uff0c\u8fd9\u79cd\u5206\u914d\u65b9\u5f0f\u79f0\u4e3a\u201c\u7a7a\u95f2\u5217\u8868\u201d\uff08Free 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Header\uff09\u4e4b\u4e2d\u3002\u6839\u636e\u865a\u62df\u673a\u5f53\u524d\u7684\u8fd0\u884c\u72b6\u6001\u7684\u4e0d\u540c\uff0c\u5982\u662f\u5426\u542f\u7528\u504f\u5411\u9501\u7b49\uff0c\u5bf9\u8c61\u5934\u4f1a\u6709\u4e0d\u540c\u7684\u8bbe\u7f6e\u65b9\u5f0f\u3002<\/p>\n\n\n<p>5.\u5728\u4e0a\u9762\u5de5\u4f5c\u90fd\u5b8c\u6210\u4e4b\u540e\uff0c\u4ece\u865a\u62df\u673a\u7684\u89d2\u5ea6\u6765\u8bf4\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\u5df2\u7ecf\u5b8c\u6210\u4e86\u3002\u4f46\u662f\u4eceJava\u7a0b\u5e8f\u7684\u89d2\u5ea6\u6765\u8bf4\uff0c\u8fd8\u9700\u8981\u8c03\u7528&lt;init&gt;\u65b9\u6cd5\uff0c\u8fd9\u6837\u4e00\u4e2a\u771f\u6b63\u7684\u5bf9\u8c61\u624d\u7b97\u5b8c\u5168\u4ea7\u751f\u51fa\u6765\u3002<\/p>\n\n\n<h3 class=\"wp-block-heading\">2.2 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Data\uff09\u548c\u5bf9\u9f50\u586b\u5145\uff08Padding\uff09\u3002<\/p>\n\n\n<p>HotSpot\u865a\u62df\u673a\u7684\u5bf9\u8c61\u5934\u5305\u62ec\u4e24\u90e8\u5206\u4fe1\u606f\uff0c\u7b2c\u4e00\u90e8\u5206\u7528\u4e8e\u5b58\u50a8\u5bf9\u8c61\u81ea\u8eab\u7684\u8fd0\u884c\u65f6\u6570\u636e\uff0c\u5982\u54c8\u5e0c\u7801\uff08HashCode\uff09\u3001GC\u5206\u4ee3\u5e74\u9f84\u3001\u9501\u72b6\u6001\u6807\u5fd7\u3001\u7ebf\u7a0b\u6301\u6709\u7684\u9501\u3001\u504f\u5411\u7ebf\u7a0bID\u3001\u504f\u5411\u65f6\u95f4\u6233\u7b49\u7b49\u3002\u8fd9\u90e8\u5206\u6570\u636e\u7684\u957f\u5ea6\u572832\u4f4d\u548c64\u4f4d\u7684\u865a\u62df\u673a\u4e2d\u5206\u522b\u4e3a32bit\u548c64bit\uff08\u672a\u5f00\u542f\u538b\u7f29\u6307\u9488\uff09\uff0c\u5b98\u65b9\u79f0\u4ed6\u4e3a\u201cMark 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class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"757\" height=\"321\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-8.png\" alt=\"\" class=\"wp-image-1370\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-8.png 757w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-8-300x127.png 300w\" sizes=\"(max-width: 757px) 100vw, 757px\" \/><\/figure><\/div>\n\n\n<p>\u5982\u679c\u4f7f\u7528\u6307\u9488\u76f4\u63a5\u8bbf\u95ee\uff0c\u90a3\u4e48Java\u5806\u5bf9\u8c61\u7684\u5e03\u5c40\u4e2d\u5c31\u5fc5\u987b\u8003\u8651\u5982\u4f55\u653e\u7f6e\u8bbf\u95ee\u7c7b\u578b\u6570\u636e\u7684\u76f8\u5173\u4fe1\u606f\uff0c\u800creference\u4e2d\u5b58\u50a8\u7684\u76f4\u63a5\u5c31\u662f\u5bf9\u8c61\u5730\u5740\u3002<\/p>\n\n\n<p>\u4f7f\u7528\u76f4\u63a5\u6307\u9488\u8bbf\u95ee\u65b9\u5f0f\u6700\u5927\u7684\u597d\u5904\u5c31\u662f\u901f\u5ea6\u66f4\u5feb\uff0c\u5b83\u8282\u7701\u4e86\u4e00\u6b21\u6307\u9488\u5b9a\u4f4d\u65f6\u7684\u5f00\u9500\uff0c\u7531\u4e8e\u5bf9\u8c61\u7684\u8bbf\u95ee\u5728Java\u4e2d\u975e\u5e38\u9891\u7e41\uff0c\u56e0\u6b64\u8fd9\u7c7b\u5f00\u9500\u79ef\u5c11\u6210\u591a\u540e\u4e5f\u662f\u4e00\u9879\u975e\u5e38\u53ef\u89c2\u7684\u6267\u884c\u6210\u672c\u3002<\/p>\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"759\" height=\"322\" src=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-9.png\" alt=\"\" class=\"wp-image-1371\" srcset=\"http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-9.png 759w, http:\/\/www.sniper97.cn\/wp-content\/uploads\/2019\/08\/\u56fe\u7247-9-300x127.png 300w\" sizes=\"(max-width: 759px) 100vw, 759px\" \/><\/figure><\/div>\n\n\n<p>\u76ee\u524dSun HotSpot\u4e3b\u8981\u4f7f\u7528\u7b2c\u4e8c\u79cd\uff0c\u5373\u76f4\u63a5\u6307\u9488\u8bbf\u95ee\u65b9\u5f0f\u8fdb\u884c\u3002<\/p>\n\n\n<h2 class=\"wp-block-heading\">3 OutOfMemoryError\u5f02\u5e38<\/h2>\n\n\n<h3 class=\"wp-block-heading\">3.1 Java\u5806\u6ea2\u51fa<\/h3>\n\n\n<p>\u5f53\u51fa\u73b0Java\u5806\u6ea2\u51fa\u65f6\uff0c\u5f02\u5e38\u5806\u6808\u4fe1\u606f\u4f1a\u663e\u793a\u201cjava.lang.OutOfMemoryError\u201d\u5e76\u4e14\u4f1a\u8fdb\u4e00\u6b65\u63d0\u793a\u201cJava heap 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