{"id":99,"date":"2025-07-12T12:27:57","date_gmt":"2025-07-12T04:27:57","guid":{"rendered":"https:\/\/yingjun.run\/?p=99"},"modified":"2025-07-12T18:18:14","modified_gmt":"2025-07-12T10:18:14","slug":"java%e5%9f%ba%e7%a1%80","status":"publish","type":"post","link":"https:\/\/yingjun.run\/index.php\/2025\/07\/12\/java%e5%9f%ba%e7%a1%80\/","title":{"rendered":"Java\u57fa\u7840\u4e0a"},"content":{"rendered":"<h3><span class=\"ez-toc-section\" id=\"Java%E8%AF%AD%E8%A8%80%E6%9C%89%E5%93%AA%E4%BA%9B%E7%89%B9%E7%82%B9\"><\/span>Java\u8bed\u8a00\u6709\u54ea\u4e9b\u7279\u70b9<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u7b80\u5355\u6613\u5b66\uff08\u8bed\u6cd5\u7b80\u5355\uff0c\u4e0a\u624b\u5bb9\u6613\uff09\uff1b\u9762\u5411\u5bf9\u8c61\uff08\u5c01\u88c5\uff0c\u7ee7\u627f\uff0c\u591a\u6001\uff09\uff1b<br \/>\n\u5e73\u53f0\u65e0\u5173\u6027\uff08 Java \u865a\u62df\u673a\u5b9e\u73b0\u5e73\u53f0\u65e0\u5173\u6027\uff09\uff1b<br \/>\n\u652f\u6301\u591a\u7ebf\u7a0b\uff08 C++ \u8bed\u8a00\u6ca1\u6709\u5185\u7f6e\u7684\u591a\u7ebf\u7a0b\u673a\u5236\uff0c\u56e0\u6b64\u5fc5\u987b\u8c03\u7528\u64cd\u4f5c\u7cfb\u7edf\u7684\u591a\u7ebf\u7a0b\u529f\u80fd\u6765\u8fdb\u884c\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u8bbe\u8ba1\uff0c\u800c Java \u8bed\u8a00\u5374\u63d0\u4f9b\u4e86\u591a\u7ebf\u7a0b\u652f\u6301\uff09\uff1b<br \/>\n\u53ef\u9760\u6027\uff08\u5177\u5907\u5f02\u5e38\u5904\u7406\u548c\u81ea\u52a8\u5185\u5b58\u7ba1\u7406\u673a\u5236\uff09\uff1b<br \/>\n\u5b89\u5168\u6027\uff08Java \u8bed\u8a00\u672c\u8eab\u7684\u8bbe\u8ba1\u5c31\u63d0\u4f9b\u4e86\u591a\u91cd\u5b89\u5168\u9632\u62a4\u673a\u5236\u5982\u8bbf\u95ee\u6743\u9650\u4fee\u9970\u7b26\u3001\u9650\u5236\u7a0b\u5e8f\u76f4\u63a5\u8bbf\u95ee\u64cd\u4f5c\u7cfb\u7edf\u8d44\u6e90\uff09\uff1b<br \/>\n\u9ad8\u6548\u6027\uff08\u901a\u8fc7 Just In Time \u7f16\u8bd1\u5668\u7b49\u6280\u672f\u7684\u4f18\u5316\uff0cJava \u8bed\u8a00\u7684\u8fd0\u884c\u6548\u7387\u8fd8\u662f\u975e\u5e38\u4e0d\u9519\u7684\uff09\uff1b<br \/>\n\u652f\u6301\u7f51\u7edc\u7f16\u7a0b\u5e76\u4e14\u5f88\u65b9\u4fbf\uff1b\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5e76\u5b58<\/p>\n<h3><span class=\"ez-toc-section\" id=\"JDK_%E5%92%8C_JRE\"><\/span>JDK \u548c JRE<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>JDK\uff08Java Development Kit\uff09\u662f\u4e00\u4e2a\u529f\u80fd\u9f50\u5168\u7684 Java \u5f00\u53d1\u5de5\u5177\u5305\uff0c\u4f9b\u5f00\u53d1\u8005\u4f7f\u7528\uff0c\u7528\u4e8e\u521b\u5efa\u548c\u7f16\u8bd1 Java \u7a0b\u5e8f\u3002\u5b83\u5305\u542b\u4e86 JRE\uff08Java Runtime Environment\uff09\uff0c\u4ee5\u53ca\u7f16\u8bd1\u5668 javac \u548c\u5176\u4ed6\u5de5\u5177\uff0c\u5982 javadoc\uff08\u6587\u6863\u751f\u6210\u5668\uff09\u3001jdb\uff08\u8c03\u8bd5\u5668\uff09\u3001jconsole\uff08\u76d1\u63a7\u5de5\u5177\uff09\u3001javap\uff08\u53cd\u7f16\u8bd1\u5de5\u5177\uff09\u7b49<br \/>\nJRE \u662f\u8fd0\u884c\u5df2\u7f16\u8bd1 Java \u7a0b\u5e8f\u6240\u9700\u7684\u73af\u5883\uff0c\u4e3b\u8981\u5305\u542b\u4ee5\u4e0b\u4e24\u4e2a\u90e8\u5206\uff1a<br \/>\nJVM : \u4e5f\u5c31\u662f\u6211\u4eec\u4e0a\u9762\u63d0\u5230\u7684 Java \u865a\u62df\u673a\u3002<br \/>\nJava \u57fa\u7840\u7c7b\u5e93\uff08Class Library\uff09\uff1a\u4e00\u7ec4\u6807\u51c6\u7684\u7c7b\u5e93\uff0c\u63d0\u4f9b\u5e38\u7528\u7684\u529f\u80fd\u548c API\uff08\u5982 I\/O \u64cd\u4f5c\u3001\u7f51\u7edc\u901a\u4fe1\u3001\u6570\u636e\u7ed3\u6784\u7b49\uff09<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752295390703.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BB%80%E4%B9%88%E6%98%AF%E5%AD%97%E8%8A%82%E7%A0%81%E9%87%87%E7%94%A8%E5%AD%97%E8%8A%82%E7%A0%81%E7%9A%84%E5%A5%BD%E5%A4%84%E6%98%AF%E4%BB%80%E4%B9%88\"><\/span>\u4ec0\u4e48\u662f\u5b57\u8282\u7801?\u91c7\u7528\u5b57\u8282\u7801\u7684\u597d\u5904\u662f\u4ec0\u4e48?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u5728 Java \u4e2d\uff0cJVM \u53ef\u4ee5\u7406\u89e3\u7684\u4ee3\u7801\u5c31\u53eb\u505a\u5b57\u8282\u7801\uff08\u5373\u6269\u5c55\u540d\u4e3a .class \u7684\u6587\u4ef6\uff09\uff0c\u5b83\u4e0d\u9762\u5411\u4efb\u4f55\u7279\u5b9a\u7684\u5904\u7406\u5668\uff0c\u53ea\u9762\u5411\u865a\u62df\u673a\u3002Java \u8bed\u8a00\u901a\u8fc7\u5b57\u8282\u7801\u7684\u65b9\u5f0f\uff0c\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u89e3\u51b3\u4e86\u4f20\u7edf\u89e3\u91ca\u578b\u8bed\u8a00\u6267\u884c\u6548\u7387\u4f4e\u7684\u95ee\u9898\uff0c\u540c\u65f6\u53c8\u4fdd\u7559\u4e86\u89e3\u91ca\u578b\u8bed\u8a00\u53ef\u79fb\u690d\u7684\u7279\u70b9\u3002\u6240\u4ee5\uff0c Java \u7a0b\u5e8f\u8fd0\u884c\u65f6\u76f8\u5bf9\u6765\u8bf4\u8fd8\u662f\u9ad8\u6548\u7684\uff08\u4e0d\u8fc7\uff0c\u548c C\u3001 C++\uff0cRust\uff0cGo \u7b49\u8bed\u8a00\u8fd8\u662f\u6709\u4e00\u5b9a\u5dee\u8ddd\u7684\uff09\uff0c\u800c\u4e14\uff0c\u7531\u4e8e\u5b57\u8282\u7801\u5e76\u4e0d\u9488\u5bf9\u4e00\u79cd\u7279\u5b9a\u7684\u673a\u5668\uff0c\u56e0\u6b64\uff0cJava \u7a0b\u5e8f\u65e0\u987b\u91cd\u65b0\u7f16\u8bd1\u4fbf\u53ef\u5728\u591a\u79cd\u4e0d\u540c\u64cd\u4f5c\u7cfb\u7edf\u7684\u8ba1\u7b97\u673a\u4e0a\u8fd0\u884c\u3002<br \/>\n<img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752295596566.png\" alt=\"file\" \/><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752295612792.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E9%9D%A2%E5%90%91%E5%AF%B9%E8%B1%A1%E5%92%8C%E9%9D%A2%E5%90%91%E8%BF%87%E7%A8%8B%E7%9A%84%E5%8C%BA%E5%88%AB\"><\/span>\u9762\u5411\u5bf9\u8c61\u548c\u9762\u5411\u8fc7\u7a0b\u7684\u533a\u522b<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u9762\u5411\u8fc7\u7a0b<\/strong>\uff1a\u662f\u5206\u6790\u89e3\u51b3\u95ee\u9898\u7684\u6b65\u9aa4\uff0c\u7136\u540e\u7528\u51fd\u6570\u628a\u8fd9\u4e9b\u6b65\u9aa4\u4e00\u6b65\u4e00\u6b65\u5730\u5b9e\u73b0\uff0c\u7136\u540e\u5728\u4f7f\u7528\u7684\u65f6\u5019\u4e00\u4e00\u8c03\u7528\u5219\u53ef\u3002\u6027\u80fd\u8f83\u9ad8\uff0c\u6240\u4ee5\u5355\u7247\u673a\u3001\u5d4c\u5165\u5f0f\u5f00\u53d1\u7b49\u4e00\u822c\u91c7\u7528\u9762\u5411\u8fc7\u7a0b\u5f00\u53d1<br \/>\n<strong>\u9762\u5411\u5bf9\u8c61<\/strong>\uff1a\u662f\u628a\u6784\u6210\u95ee\u9898\u7684\u4e8b\u52a1\u5206\u89e3\u6210\u5404\u4e2a\u5bf9\u8c61\uff0c\u800c\u5efa\u7acb\u5bf9\u8c61\u7684\u76ee\u7684\u4e5f\u4e0d\u662f\u4e3a\u4e86\u5b8c\u6210\u4e00\u4e2a\u4e2a\u6b65\u9aa4\uff0c\u800c\u662f\u4e3a\u4e86\u63cf\u8ff0\u67d0\u4e2a\u4e8b\u7269\u5728\u89e3\u51b3\u6574\u4e2a\u95ee\u9898\u7684\u8fc7\u7a0b\u4e2d\u6240\u53d1\u751f\u7684\u884c\u4e3a\u3002\u9762\u5411\u5bf9\u8c61\u6709\u5c01\u88c5\u3001\u7ee7\u627f\u3001\u591a\u6001\u7684\u7279\u6027\uff0c\u6240\u4ee5\u6613\u7ef4\u62a4\u3001\u6613\u590d\u7528\u3001\u6613\u6269\u5c55\u3002\u53ef\u4ee5\u8bbe\u8ba1\u51fa\u4f4e\u8026\u5408\u7684\u7cfb\u7edf\u3002 \u4f46\u662f\u6027\u80fd\u4e0a\u6765\u8bf4\uff0c\u6bd4\u9762\u5411\u8fc7\u7a0b\u8981\u4f4e\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"instanceof_%E5%85%B3%E9%94%AE%E5%AD%97%E7%9A%84%E4%BD%9C%E7%94%A8\"><\/span>instanceof \u5173\u952e\u5b57\u7684\u4f5c\u7528<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>instanceof \u4e25\u683c\u6765\u8bf4\u662fJava\u4e2d\u7684\u4e00\u4e2a\u53cc\u76ee\u8fd0\u7b97\u7b26\uff0c\u7528\u6765\u6d4b\u8bd5\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u4e3a\u4e00\u4e2a\u7c7b\u7684\u5b9e\u4f8b\uff0c\u7528\u6cd5\u4e3a\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">boolean result = obj instanceof Class<\/code><\/pre>\n<p>\u5176\u4e2d obj \u4e3a\u4e00\u4e2a\u5bf9\u8c61\uff0cClass \u8868\u793a\u4e00\u4e2a\u7c7b\u6216\u8005\u4e00\u4e2a\u63a5\u53e3\uff0c\u5f53 obj \u4e3a Class \u7684\u5bf9\u8c61\uff0c\u6216\u8005\u662f\u5176\u76f4\u63a5\u6216\u95f4\u63a5\u5b50\u7c7b\uff0c\u6216\u8005\u662f\u5176\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b\uff0c\u7ed3\u679cresult \u90fd\u8fd4\u56de true\uff0c\u5426\u5219\u8fd4\u56defalse\u3002\u6ce8\u610f\uff1a\u7f16\u8bd1\u5668\u4f1a\u68c0\u67e5 obj \u662f\u5426\u80fd\u8f6c\u6362\u6210\u53f3\u8fb9\u7684class\u7c7b\u578b\uff0c\u5982\u679c\u4e0d\u80fd\u8f6c\u6362\u5219\u76f4\u63a5\u62a5\u9519\uff0c\u5982\u679c\u4e0d\u80fd\u786e\u5b9a\u7c7b\u578b\uff0c\u5219\u901a\u8fc7\u7f16\u8bd1\uff0c\u5177\u4f53\u770b\u8fd0\u884c\u65f6\u5b9a\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">int i = 0;\nSystem.out.println(i instanceof Integer);\/\/\u7f16\u8bd1\u4e0d\u901a\u8fc7 i\u5fc5\u987b\u662f\u5f15\u7528\u7c7b\u578b\uff0c\u4e0d\u80fd\u662f\u57fa\u672c\u7c7b\u578b\nSystem.out.println(i instanceof Object);\/\/\u7f16\u8bd1\u4e0d\u901a\u8fc7\n\nInteger integer = new Integer(1);\nSystem.out.println(integer instanceof Integer);\/\/true\n\n\/false ,\u5728 JavaSE\u89c4\u8303 \u4e2d\u5bf9 instanceof \u8fd0\u7b97\u7b26\u7684\u89c4\u5b9a\u5c31\u662f\uff1a\u5982\u679c obj \u4e3a null\uff0c\u90a3\u4e48\u5c06\u8fd4\n\u56de false\u3002\nSystem.out.println(null instanceof Object);<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E8%AF%B4_Java_%E8%AF%AD%E8%A8%80%E2%80%9C%E7%BC%96%E8%AF%91%E4%B8%8E%E8%A7%A3%E9%87%8A%E5%B9%B6%E5%AD%98%E2%80%9D%EF%BC%9F\"><\/span>\u4e3a\u4ec0\u4e48\u8bf4 Java \u8bed\u8a00\u201c\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5e76\u5b58\u201d\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u6211\u4eec\u53ef\u4ee5\u5c06\u9ad8\u7ea7\u7f16\u7a0b\u8bed\u8a00\u6309\u7167\u7a0b\u5e8f\u7684\u6267\u884c\u65b9\u5f0f\u5206\u4e3a\u4e24\u79cd\uff1a\u7f16\u8bd1\u578b\uff1a\u7f16\u8bd1\u578b\u8bed\u8a00 \u4f1a\u901a\u8fc7\u7f16\u8bd1\u5668\u5c06\u6e90\u4ee3\u7801\u4e00\u6b21\u6027\u7ffb\u8bd1\u6210\u53ef\u88ab\u8be5\u5e73\u53f0\u6267\u884c\u7684\u673a\u5668\u7801\u3002\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u7f16\u8bd1\u8bed\u8a00\u7684\u6267\u884c\u901f\u5ea6\u6bd4\u8f83\u5feb\uff0c\u5f00\u53d1\u6548\u7387\u6bd4\u8f83\u4f4e\u3002\u5e38\u89c1\u7684\u7f16\u8bd1\u6027\u8bed\u8a00\u6709 C\u3001C++\u3001Go\u3001Rust \u7b49\u7b49\u3002\u89e3\u91ca\u578b\uff1a\u89e3\u91ca\u578b\u8bed\u8a00\u4f1a\u901a\u8fc7\u89e3\u91ca\u5668\u4e00\u53e5\u4e00\u53e5\u7684\u5c06\u4ee3\u7801\u89e3\u91ca\uff08interpret\uff09\u4e3a\u673a\u5668\u4ee3\u7801\u540e\u518d\u6267\u884c\u3002\u89e3\u91ca\u578b\u8bed\u8a00\u5f00\u53d1\u6548\u7387\u6bd4\u8f83\u5feb\uff0c\u6267\u884c\u901f\u5ea6\u6bd4\u8f83\u6162\u3002\u5e38\u89c1\u7684\u89e3\u91ca\u6027\u8bed\u8a00\u6709 Python\u3001JavaScript\u3001PHP \u7b49\u7b49\u3002<br \/>\n<img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752295769688.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E8%AF%B4_Java_%E8%AF%AD%E8%A8%80%E2%80%9C%E7%BC%96%E8%AF%91%E4%B8%8E%E8%A7%A3%E9%87%8A%E5%B9%B6%E5%AD%98%E2%80%9D%EF%BC%9F-2\"><\/span>\u4e3a\u4ec0\u4e48\u8bf4 Java \u8bed\u8a00\u201c\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5e76\u5b58\u201d\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u8fd9\u662f\u56e0\u4e3a Java \u8bed\u8a00\u65e2\u5177\u6709\u7f16\u8bd1\u578b\u8bed\u8a00\u7684\u7279\u5f81\uff0c\u4e5f\u5177\u6709\u89e3\u91ca\u578b\u8bed\u8a00\u7684\u7279\u5f81\u3002\u56e0\u4e3a Java \u7a0b\u5e8f\u8981\u7ecf\u8fc7\u5148\u7f16\u8bd1\uff0c\u540e\u89e3\u91ca\u4e24\u4e2a\u6b65\u9aa4\uff0c\u7531 Java \u7f16\u5199\u7684\u7a0b\u5e8f\u9700\u8981\u5148\u7ecf\u8fc7\u7f16\u8bd1\u6b65\u9aa4\uff0c\u751f\u6210\u5b57\u8282\u7801\uff08.class \u6587\u4ef6\uff09\uff0c\u8fd9\u79cd\u5b57\u8282\u7801\u5fc5\u987b\u7531 Java \u89e3\u91ca\u5668\u6765\u89e3\u91ca\u6267\u884c<\/p>\n<h3><span class=\"ez-toc-section\" id=\"AOT_%E6%9C%89%E4%BB%80%E4%B9%88%E4%BC%98%E7%82%B9%EF%BC%9F%E4%B8%BA%E4%BB%80%E4%B9%88%E4%B8%8D%E5%85%A8%E9%83%A8%E4%BD%BF%E7%94%A8_AOT_%E5%91%A2%EF%BC%9F\"><\/span>AOT \u6709\u4ec0\u4e48\u4f18\u70b9\uff1f\u4e3a\u4ec0\u4e48\u4e0d\u5168\u90e8\u4f7f\u7528 AOT \u5462\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>JDK 9 \u5f15\u5165\u4e86\u4e00\u79cd\u65b0\u7684\u7f16\u8bd1\u6a21\u5f0f AOT(Ahead of Time Compilation) \u3002\u548c JIT \u4e0d\u540c\u7684\u662f\uff0c\u8fd9\u79cd\u7f16\u8bd1\u6a21\u5f0f\u4f1a\u5728\u7a0b\u5e8f\u88ab\u6267\u884c\u524d\u5c31\u5c06\u5176\u7f16\u8bd1\u6210\u673a\u5668\u7801\uff0c\u5c5e\u4e8e\u9759\u6001\u7f16\u8bd1\uff08C\u3001 C++\uff0cRust\uff0cGo \u7b49\u8bed\u8a00\u5c31\u662f\u9759\u6001\u7f16\u8bd1\uff09\u3002AOT \u907f\u514d\u4e86 JIT \u9884\u70ed\u7b49\u5404\u65b9\u9762\u7684\u5f00\u9500\uff0c\u53ef\u4ee5\u63d0\u9ad8 Java \u7a0b\u5e8f\u7684\u542f\u52a8\u901f\u5ea6\uff0c\u907f\u514d\u9884\u70ed\u65f6\u95f4\u957f\u3002\u5e76\u4e14\uff0cAOT \u8fd8\u80fd\u51cf\u5c11\u5185\u5b58\u5360\u7528\u548c\u589e\u5f3a Java \u7a0b\u5e8f\u7684\u5b89\u5168\u6027\uff08AOT \u7f16\u8bd1\u540e\u7684\u4ee3\u7801\u4e0d\u5bb9\u6613\u88ab\u53cd\u7f16\u8bd1\u548c\u4fee\u6539\uff09\uff0c\u7279\u522b\u9002\u5408\u4e91\u539f\u751f\u573a\u666f\u3002<br \/>\n<img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752295820347.png\" alt=\"file\" \/><br \/>\n\u53ef\u4ee5\u770b\u51fa\uff0cAOT \u7684\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e\u542f\u52a8\u65f6\u95f4\u3001\u5185\u5b58\u5360\u7528\u548c\u6253\u5305\u4f53\u79ef\u3002JIT \u7684\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e\u5177\u5907\u66f4\u9ad8\u7684\u6781\u9650\u5904\u7406\u80fd\u529b\uff0c\u53ef\u4ee5\u964d\u4f4e\u8bf7\u6c42\u7684\u6700\u5927\u5ef6\u8fdf\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E6%97%A2%E7%84%B6_AOT_%E8%BF%99%E4%B9%88%E5%A4%9A%E4%BC%98%E7%82%B9%EF%BC%8C%E9%82%A3%E4%B8%BA%E4%BB%80%E4%B9%88%E4%B8%8D%E5%85%A8%E9%83%A8%E4%BD%BF%E7%94%A8%E8%BF%99%E7%A7%8D%E7%BC%96%E8%AF%91%E6%96%B9%E5%BC%8F%E5%91%A2%EF%BC%9F\"><\/span>\u65e2\u7136 AOT \u8fd9\u4e48\u591a\u4f18\u70b9\uff0c\u90a3\u4e3a\u4ec0\u4e48\u4e0d\u5168\u90e8\u4f7f\u7528\u8fd9\u79cd\u7f16\u8bd1\u65b9\u5f0f\u5462\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u6211\u4eec\u524d\u9762\u4e5f\u5bf9\u6bd4\u8fc7 JIT \u4e0e AOT\uff0c\u4e24\u8005\u5404\u6709\u4f18\u70b9\uff0c\u53ea\u80fd\u8bf4 AOT \u66f4\u9002\u5408\u5f53\u4e0b\u7684\u4e91\u539f\u751f\u573a\u666f\uff0c\u5bf9\u5fae\u670d\u52a1\u67b6\u6784\u7684\u652f\u6301\u4e5f\u6bd4\u8f83\u53cb\u597d\u3002\u9664\u6b64\u4e4b\u5916\uff0cAOT \u7f16\u8bd1\u65e0\u6cd5\u652f\u6301 Java \u7684\u4e00\u4e9b\u52a8\u6001\u7279\u6027\uff0c\u5982\u53cd\u5c04\u3001\u52a8\u6001\u4ee3\u7406\u3001\u52a8\u6001\u52a0\u8f7d\u3001JNI\uff08Java Native Interface\uff09\u7b49\u3002\u7136\u800c\uff0c\u5f88\u591a\u6846\u67b6\u548c\u5e93\uff08\u5982 Spring\u3001CGLIB\uff09\u90fd\u7528\u5230\u4e86\u8fd9\u4e9b\u7279\u6027\u3002\u5982\u679c\u53ea\u4f7f\u7528 AOT \u7f16\u8bd1\uff0c\u90a3\u5c31\u6ca1\u529e\u6cd5\u4f7f\u7528\u8fd9\u4e9b\u6846\u67b6\u548c\u5e93\u4e86\uff0c\u6216\u8005\u8bf4\u9700\u8981\u9488\u5bf9\u6027\u5730\u53bb\u505a\u9002\u914d\u548c\u4f18\u5316\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0cCGLIB \u52a8\u6001\u4ee3\u7406\u4f7f\u7528\u7684\u662f ASM \u6280\u672f\uff0c\u800c\u8fd9\u79cd\u6280\u672f\u5927\u81f4\u539f\u7406\u662f\u8fd0\u884c\u65f6\u76f4\u63a5\u5728\u5185\u5b58\u4e2d\u751f\u6210\u5e76\u52a0\u8f7d\u4fee\u6539\u540e\u7684\u5b57\u8282\u7801\u6587\u4ef6\u4e5f\u5c31\u662f .class \u6587\u4ef6\uff0c\u5982\u679c\u5168\u90e8\u4f7f\u7528 AOT \u63d0\u524d\u7f16\u8bd1\uff0c\u4e5f\u5c31\u4e0d\u80fd\u4f7f\u7528 ASM \u6280\u672f\u4e86\u3002\u4e3a\u4e86\u652f\u6301\u7c7b\u4f3c\u7684\u52a8\u6001\u7279\u6027\uff0c\u6240\u4ee5\u9009\u62e9\u4f7f\u7528 JIT \u5373\u65f6\u7f16\u8bd1\u5668\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Java_%E5%92%8C_C_%E7%9A%84%E5%8C%BA%E5%88%AB\"><\/span>Java \u548c C++ \u7684\u533a\u522b?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Java \u4e0d\u63d0\u4f9b\u6307\u9488\u6765\u76f4\u63a5\u8bbf\u95ee\u5185\u5b58\uff0c\u7a0b\u5e8f\u5185\u5b58\u66f4\u52a0\u5b89\u5168Java \u7684\u7c7b\u662f\u5355\u7ee7\u627f\u7684\uff0cC++ \u652f\u6301\u591a\u91cd\u7ee7\u627f\uff1b\u867d\u7136 Java \u7684\u7c7b\u4e0d\u53ef\u4ee5\u591a\u7ee7\u627f\uff0c\u4f46\u662f\u63a5\u53e3\u53ef\u4ee5\u591a\u7ee7\u627f\u3002Java \u6709\u81ea\u52a8\u5185\u5b58\u7ba1\u7406\u5783\u573e\u56de\u6536\u673a\u5236(GC)\uff0c\u4e0d\u9700\u8981\u7a0b\u5e8f\u5458\u624b\u52a8\u91ca\u653e\u65e0\u7528\u5185\u5b58\u3002C ++\u540c\u65f6\u652f\u6301\u65b9\u6cd5\u91cd\u8f7d\u548c\u64cd\u4f5c\u7b26\u91cd\u8f7d\uff0c\u4f46\u662f Java \u53ea\u652f\u6301\u65b9\u6cd5\u91cd\u8f7d\uff08\u64cd\u4f5c\u7b26\u91cd\u8f7d\u589e\u52a0\u4e86\u590d\u6742\u6027\uff0c\u8fd9\u4e0e Java \u6700\u521d\u7684\u8bbe\u8ba1\u601d\u60f3\u4e0d\u7b26\uff09\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%BD%BF%E7%94%A8%E7%A7%BB%E4%BD%8D%E8%BF%90%E7%AE%97%E7%AC%A6%E7%9A%84%E4%B8%BB%E8%A6%81%E5%8E%9F%E5%9B%A0%EF%BC%9A\"><\/span>\u4f7f\u7528\u79fb\u4f4d\u8fd0\u7b97\u7b26\u7684\u4e3b\u8981\u539f\u56e0\uff1a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u9ad8\u6548<\/strong>\uff1a\u79fb\u4f4d\u8fd0\u7b97\u7b26\u76f4\u63a5\u5bf9\u5e94\u4e8e\u5904\u7406\u5668\u7684\u79fb\u4f4d\u6307\u4ee4\u3002\u73b0\u4ee3\u5904\u7406\u5668\u5177\u6709\u4e13\u95e8\u7684\u786c\u4ef6\u6307\u4ee4\u6765\u6267\u884c\u8fd9\u4e9b\u79fb\u4f4d\u64cd\u4f5c\uff0c\u8fd9\u4e9b\u6307\u4ee4\u901a\u5e38\u5728\u4e00\u4e2a\u65f6\u949f\u5468\u671f\u5185\u5b8c\u6210\u3002\u76f8\u6bd4\u4e4b\u4e0b\uff0c\u4e58\u6cd5\u548c\u9664\u6cd5\u7b49\u7b97\u672f\u8fd0\u7b97\u5728\u786c\u4ef6\u5c42\u9762\u4e0a\u9700\u8981\u66f4\u591a\u7684\u65f6\u949f\u5468\u671f\u6765\u5b8c\u6210\u3002<br \/>\n<strong>\u8282\u7701\u5185\u5b58<\/strong>\uff1a\u901a\u8fc7\u79fb\u4f4d\u64cd\u4f5c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4e00\u4e2a\u6574\u6570\uff08\u5982 int \u6216 long\uff09\u6765\u5b58\u50a8\u591a\u4e2a\u5e03\u5c14\u503c\u6216\u6807\u5fd7\u4f4d\uff0c\u4ece\u800c\u8282\u7701\u5185\u5b58\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Java_%E4%B8%AD%E7%9A%84%E5%87%A0%E7%A7%8D%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B\"><\/span>Java \u4e2d\u7684\u51e0\u79cd\u57fa\u672c\u6570\u636e\u7c7b\u578b<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Java \u4e2d\u6709 8 \u79cd\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u5206\u522b\u4e3a\uff1a<br \/>\n6 \u79cd\u6570\u5b57\u7c7b\u578b\uff1a 4 \u79cd\u6574\u6570\u578b\uff1abyte\u3001short\u3001int\u3001long2 \u79cd\u6d6e\u70b9\u578b\uff1afloat\u3001double<br \/>\n1 \u79cd\u5b57\u7b26\u7c7b\u578b\uff1achar<br \/>\n1 \u79cd\u5e03\u5c14\u578b\uff1aboolean<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752296180537.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%9F%BA%E6%9C%AC%E7%B1%BB%E5%9E%8B%E5%92%8C%E5%8C%85%E8%A3%85%E7%B1%BB%E5%9E%8B%E7%9A%84%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>\u57fa\u672c\u7c7b\u578b\u548c\u5305\u88c5\u7c7b\u578b\u7684\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u7528\u9014\uff1a<\/strong>\u9664\u4e86\u5b9a\u4e49\u4e00\u4e9b\u5e38\u91cf\u548c\u5c40\u90e8\u53d8\u91cf\u4e4b\u5916\uff0c\u6211\u4eec\u5728\u5176\u4ed6\u5730\u65b9\u6bd4\u5982\u65b9\u6cd5\u53c2\u6570\u3001\u5bf9\u8c61\u5c5e\u6027\u4e2d\u5f88\u5c11\u4f1a\u4f7f\u7528\u57fa\u672c\u7c7b\u578b\u6765\u5b9a\u4e49\u53d8\u91cf\u3002\u5e76\u4e14\uff0c\u5305\u88c5\u7c7b\u578b\u53ef\u7528\u4e8e\u6cdb\u578b\uff0c\u800c\u57fa\u672c\u7c7b\u578b\u4e0d\u53ef\u4ee5\u3002<br \/>\n<strong>\u5b58\u50a8\u65b9\u5f0f<\/strong>\uff1a\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u5c40\u90e8\u53d8\u91cf\u5b58\u653e\u5728 Java \u865a\u62df\u673a\u6808\u4e2d\u7684\u5c40\u90e8\u53d8\u91cf\u8868\u4e2d\uff0c\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u6210\u5458\u53d8\u91cf\uff08\u672a\u88ab static \u4fee\u9970 \uff09\u5b58\u653e\u5728 Java \u865a\u62df\u673a\u7684\u5806\u4e2d\u3002\u5305\u88c5\u7c7b\u578b\u5c5e\u4e8e\u5bf9\u8c61\u7c7b\u578b\uff0c\u6211\u4eec\u77e5\u9053\u51e0\u4e4e\u6240\u6709\u5bf9\u8c61\u5b9e\u4f8b\u90fd\u5b58\u5728\u4e8e\u5806\u4e2d\u3002<br \/>\n<strong>\u5360\u7528\u7a7a\u95f4<\/strong>\uff1a\u76f8\u6bd4\u4e8e\u5305\u88c5\u7c7b\u578b\uff08\u5bf9\u8c61\u7c7b\u578b\uff09\uff0c \u57fa\u672c\u6570\u636e\u7c7b\u578b\u5360\u7528\u7684\u7a7a\u95f4\u5f80\u5f80\u975e\u5e38\u5c0f\u3002<br \/>\n<strong>\u9ed8\u8ba4\u503c<\/strong>\uff1a\u6210\u5458\u53d8\u91cf\u5305\u88c5\u7c7b\u578b\u4e0d\u8d4b\u503c\u5c31\u662f null \uff0c\u800c\u57fa\u672c\u7c7b\u578b\u6709\u9ed8\u8ba4\u503c\u4e14\u4e0d\u662f null\u3002<br \/>\n<strong>\u6bd4\u8f83\u65b9\u5f0f<\/strong>\uff1a\u5bf9\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\u6765\u8bf4\uff0c== \u6bd4\u8f83\u7684\u662f\u503c\u3002\u5bf9\u4e8e\u5305\u88c5\u6570\u636e\u7c7b\u578b\u6765\u8bf4\uff0c== \u6bd4\u8f83\u7684\u662f\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\u3002\u6240\u6709\u6574\u578b\u5305\u88c5\u7c7b\u5bf9\u8c61\u4e4b\u95f4\u503c\u7684\u6bd4\u8f83\uff0c\u5168\u90e8\u4f7f\u7528 equals() \u65b9\u6cd5\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E8%AF%B4%E6%98%AF%E5%87%A0%E4%B9%8E%E6%89%80%E6%9C%89%E5%AF%B9%E8%B1%A1%E5%AE%9E%E4%BE%8B%E9%83%BD%E5%AD%98%E5%9C%A8%E4%BA%8E%E5%A0%86%E4%B8%AD%E5%91%A2%EF%BC%9F\"><\/span>\u4e3a\u4ec0\u4e48\u8bf4\u662f\u51e0\u4e4e\u6240\u6709\u5bf9\u8c61\u5b9e\u4f8b\u90fd\u5b58\u5728\u4e8e\u5806\u4e2d\u5462\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u8fd9\u662f\u56e0\u4e3a HotSpot \u865a\u62df\u673a\u5f15\u5165\u4e86 JIT \u4f18\u5316\u4e4b\u540e\uff0c\u4f1a\u5bf9\u5bf9\u8c61\u8fdb\u884c\u9003\u9038\u5206\u6790\uff0c\u5982\u679c\u53d1\u73b0\u67d0\u4e00\u4e2a\u5bf9\u8c61\u5e76\u6ca1\u6709\u9003\u9038\u5230\u65b9\u6cd5\u5916\u90e8\uff0c\u90a3\u4e48\u5c31\u53ef\u80fd\u901a\u8fc7\u6807\u91cf\u66ff\u6362\u6765\u5b9e\u73b0\u6808\u4e0a\u5206\u914d\uff0c\u800c\u907f\u514d\u5806\u4e0a\u5206\u914d\u5185\u5b58<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%8C%85%E8%A3%85%E7%B1%BB%E5%9E%8B%E7%9A%84%E7%BC%93%E5%AD%98%E6%9C%BA%E5%88%B6%E4%BA%86%E8%A7%A3%E4%B9%88%EF%BC%9F\"><\/span>\u5305\u88c5\u7c7b\u578b\u7684\u7f13\u5b58\u673a\u5236\u4e86\u89e3\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Java \u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u5305\u88c5\u7c7b\u578b\u7684\u5927\u90e8\u5206\u90fd\u7528\u5230\u4e86\u7f13\u5b58\u673a\u5236\u6765\u63d0\u5347\u6027\u80fd\u3002<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">Byte,Short,Integer,Long \u8fd9 4 \u79cd\u5305\u88c5\u7c7b\u9ed8\u8ba4\u521b\u5efa\u4e86\u6570\u503c [-128\uff0c127] \u7684\u76f8\u5e94\u7c7b\u578b\u7684\u7f13\u5b58\u6570\u636e\uff0cCharacter \u521b\u5efa\u4e86\u6570\u503c\u5728 [0,127] \u8303\u56f4\u7684\u7f13\u5b58\u6570\u636e\uff0cBoolean \u76f4\u63a5\u8fd4\u56de TRUE or FALSE\u3002\n\u5bf9\u4e8e Integer\uff0c\u53ef\u4ee5\u901a\u8fc7 JVM \u53c2\u6570 -XX:AutoBoxCacheMax=<size> \u4fee\u6539\u7f13\u5b58\u4e0a\u9650\uff0c\u4f46\u4e0d\u80fd\u4fee\u6539\u4e0b\u9650 -128\u3002\u5b9e\u9645\u4f7f\u7528\u65f6\uff0c\u5e76\u4e0d\u5efa\u8bae\u8bbe\u7f6e\u8fc7\u5927\u7684\u503c\uff0c\u907f\u514d\u6d6a\u8d39\u5185\u5b58\uff0c\u751a\u81f3\u662f OOM\u3002\n\u5bf9\u4e8eByte,Short,Long ,Character \u6ca1\u6709\u7c7b\u4f3c -XX:AutoBoxCacheMax \u53c2\u6570\u53ef\u4ee5\u4fee\u6539\uff0c\u56e0\u6b64\u7f13\u5b58\u8303\u56f4\u662f\u56fa\u5b9a\u7684\uff0c\u65e0\u6cd5\u901a\u8fc7 JVM \u53c2\u6570\u8c03\u6574\u3002Boolean \u5219\u76f4\u63a5\u8fd4\u56de\u9884\u5b9a\u4e49\u7684 TRUE \u548c FALSE \u5b9e\u4f8b\uff0c\u6ca1\u6709\u7f13\u5b58\u8303\u56f4\u7684\u6982\u5ff5\u3002<\/code><\/pre>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752300777504.png\" alt=\"file\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E8%87%AA%E5%8A%A8%E8%A3%85%E7%AE%B1%E4%B8%8E%E6%8B%86%E7%AE%B1%E4%BA%86%E8%A7%A3%E5%90%97%EF%BC%9F%E5%8E%9F%E7%90%86%E6%98%AF%E4%BB%80%E4%B9%88%EF%BC%9F\"><\/span>\u81ea\u52a8\u88c5\u7bb1\u4e0e\u62c6\u7bb1\u4e86\u89e3\u5417\uff1f\u539f\u7406\u662f\u4ec0\u4e48\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u4ec0\u4e48\u662f\u81ea\u52a8\u62c6\u88c5\u7bb1\uff1f<\/p>\n<p><strong>\u88c5\u7bb1\uff1a<\/strong>\u5c06\u57fa\u672c\u7c7b\u578b\u7528\u5b83\u4eec\u5bf9\u5e94\u7684\u5f15\u7528\u7c7b\u578b\u5305\u88c5\u8d77\u6765\uff1b<br \/>\n<strong>\u62c6\u7bb1<\/strong>\uff1a\u5c06\u5305\u88c5\u7c7b\u578b\u8f6c\u6362\u4e3a\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff1b<\/p>\n<p>\u4e3e\u4f8b\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">Integer i = 10;  \/\/\u88c5\u7bb1\nint n = i;   \/\/\u62c6\u7bb1<\/code><\/pre>\n<p>\u4e0a\u9762\u8fd9\u4e24\u884c\u4ee3\u7801\u5bf9\u5e94\u7684\u5b57\u8282\u7801\u4e3a\uff1a<\/p>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">   L1\n\n    LINENUMBER 8 L1\n\n    ALOAD 0\n\n    BIPUSH 10\n\n    INVOKESTATIC java\/lang\/Integer.valueOf (I)Ljava\/lang\/Integer;\n\n    PUTFIELD AutoBoxTest.i : Ljava\/lang\/Integer;\n\n   L2\n\n    LINENUMBER 9 L2\n\n    ALOAD 0\n\n    ALOAD 0\n\n    GETFIELD AutoBoxTest.i : Ljava\/lang\/Integer;\n\n    INVOKEVIRTUAL java\/lang\/Integer.intValue ()I\n\n    PUTFIELD AutoBoxTest.n : I\n\n    RETURN<\/code><\/pre>\n<p>\u4ece\u5b57\u8282\u7801\u4e2d\uff0c\u6211\u4eec\u53d1\u73b0\u88c5\u7bb1\u5176\u5b9e\u5c31\u662f\u8c03\u7528\u4e86 \u5305\u88c5\u7c7b\u7684valueOf()\u65b9\u6cd5\uff0c\u62c6\u7bb1\u5176\u5b9e\u5c31\u662f\u8c03\u7528\u4e86 xxxValue()\u65b9\u6cd5\u3002\u56e0\u6b64\uff0cInteger i = 10 \u7b49\u4ef7\u4e8e Integer i = Integer.valueOf(10)int n = i \u7b49\u4ef7\u4e8e int n = i.intValue();<\/p>\n<p><strong>\u6ce8\u610f\uff1a\u5982\u679c\u9891\u7e41\u62c6\u88c5\u7bb1\u7684\u8bdd\uff0c\u4e5f\u4f1a\u4e25\u91cd\u5f71\u54cd\u7cfb\u7edf\u7684\u6027\u80fd\u3002\u6211\u4eec\u5e94\u8be5\u5c3d\u91cf\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u62c6\u88c5\u7bb1\u64cd\u4f5c\u3002<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E6%B5%AE%E7%82%B9%E6%95%B0%E8%BF%90%E7%AE%97%E7%9A%84%E6%97%B6%E5%80%99%E4%BC%9A%E6%9C%89%E7%B2%BE%E5%BA%A6%E4%B8%A2%E5%A4%B1%E7%9A%84%E9%A3%8E%E9%99%A9%EF%BC%9F\"><\/span>\u4e3a\u4ec0\u4e48\u6d6e\u70b9\u6570\u8fd0\u7b97\u7684\u65f6\u5019\u4f1a\u6709\u7cbe\u5ea6\u4e22\u5931\u7684\u98ce\u9669\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<pre class=\"prettyprint linenums\" ><code class=\"language-java\">float a = 2.0f - 1.9f;\nfloat b = 1.8f - 1.7f;\nSystem.out.printf(&quot;%.9f&quot;,a);\/\/ 0.100000024\nSystem.out.println(b);\/\/ 0.099999905\nSystem.out.println(a == b);\/\/ false<\/code><\/pre>\n<p>\u8fd9\u4e2a\u548c\u8ba1\u7b97\u673a\u4fdd\u5b58\u6d6e\u70b9\u6570\u7684\u673a\u5236\u6709\u5f88\u5927\u5173\u7cfb\u3002\u6211\u4eec\u77e5\u9053\u8ba1\u7b97\u673a\u662f\u4e8c\u8fdb\u5236\u7684\uff0c\u800c\u4e14\u8ba1\u7b97\u673a\u5728\u8868\u793a\u4e00\u4e2a\u6570\u5b57\u65f6\uff0c\u5bbd\u5ea6\u662f\u6709\u9650\u7684\uff0c\u65e0\u9650\u5faa\u73af\u7684\u5c0f\u6570\u5b58\u50a8\u5728\u8ba1\u7b97\u673a\u65f6\uff0c\u53ea\u80fd\u88ab\u622a\u65ad\uff0c\u6240\u4ee5\u5c31\u4f1a\u5bfc\u81f4\u5c0f\u6570\u7cbe\u5ea6\u53d1\u751f\u635f\u5931\u7684\u60c5\u51b5\u3002\u8fd9\u4e5f\u5c31\u662f\u89e3\u91ca\u4e86\u4e3a\u4ec0\u4e48\u6d6e\u70b9\u6570\u6ca1\u6709\u529e\u6cd5\u7528\u4e8c\u8fdb\u5236\u7cbe\u786e\u8868\u793a\u3002\u5c31\u6bd4\u5982\u8bf4\u5341\u8fdb\u5236\u4e0b\u7684 0.2 \u5c31\u6ca1\u529e\u6cd5\u7cbe\u786e\u8f6c\u6362\u6210\u4e8c\u8fdb\u5236\u5c0f\u6570\uff1a<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%A6%82%E4%BD%95%E8%A7%A3%E5%86%B3%E6%B5%AE%E7%82%B9%E6%95%B0%E8%BF%90%E7%AE%97%E7%9A%84%E7%B2%BE%E5%BA%A6%E4%B8%A2%E5%A4%B1%E9%97%AE%E9%A2%98%EF%BC%9F\"><\/span>\u5982\u4f55\u89e3\u51b3\u6d6e\u70b9\u6570\u8fd0\u7b97\u7684\u7cbe\u5ea6\u4e22\u5931\u95ee\u9898\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>BigDecimal \u53ef\u4ee5\u5b9e\u73b0\u5bf9\u6d6e\u70b9\u6570\u7684\u8fd0\u7b97\uff0c\u4e0d\u4f1a\u9020\u6210\u7cbe\u5ea6\u4e22\u5931\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u5927\u90e8\u5206\u9700\u8981\u6d6e\u70b9\u6570\u7cbe\u786e\u8fd0\u7b97\u7ed3\u679c\u7684\u4e1a\u52a1\u573a\u666f\uff08\u6bd4\u5982\u6d89\u53ca\u5230\u94b1\u7684\u573a\u666f\uff09\u90fd\u662f\u901a\u8fc7 BigDecimal \u6765\u505a\u7684\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"BigDecimal_%E5%8F%AF%E4%BB%A5%E5%AE%9E%E7%8E%B0%E5%AF%B9%E6%B5%AE%E7%82%B9%E6%95%B0%E7%9A%84%E8%BF%90%E7%AE%97%EF%BC%8C%E4%B8%8D%E4%BC%9A%E9%80%A0%E6%88%90%E7%B2%BE%E5%BA%A6%E4%B8%A2%E5%A4%B1\"><\/span>BigDecimal \u53ef\u4ee5\u5b9e\u73b0\u5bf9\u6d6e\u70b9\u6570\u7684\u8fd0\u7b97\uff0c\u4e0d\u4f1a\u9020\u6210\u7cbe\u5ea6\u4e22\u5931<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u539f\u56e0\u5c31\u5728\u4e8e\u5b83\u628a\u5c0f\u6570\u8fd0\u7b97\u8f6c\u6362\u4e3a\u4e86\u6574\u6570\u8fd0\u7b97\u3002\u6574\u6570\u8fd0\u7b97\u662f\u7cbe\u786e\u7684\uff0c\u4e0d\u4f1a\u51fa\u73b0\u6d6e\u70b9\u6570\u90a3\u79cd\u201c\u56db\u820d\u4e94\u5165\u201d\u7684\u95ee\u9898\u3002<br \/>\n\u540c\u65f6\uff0cBigDecimal \u8fd8\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684 API\uff0c\u652f\u6301\u5404\u79cd\u6570\u5b66\u8fd0\u7b97\uff0c\u5305\u62ec\u52a0\u6cd5\u3001\u51cf\u6cd5\u3001\u4e58\u6cd5\u3001\u9664\u6cd5\u7b49\u3002\u8fd9\u4e9b\u8fd0\u7b97\u90fd\u57fa\u4e8e\u6574\u6570\u8fd0\u7b97\uff0c\u4ece\u800c\u4fdd\u8bc1\u4e86\u7cbe\u5ea6\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E6%88%90%E5%91%98%E5%8F%98%E9%87%8F%E4%B8%8E%E5%B1%80%E9%83%A8%E5%8F%98%E9%87%8F%E7%9A%84%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>\u6210\u5458\u53d8\u91cf\u4e0e\u5c40\u90e8\u53d8\u91cf\u7684\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u8bed\u6cd5\u5f62\u5f0f<\/strong>\uff1a\u4ece\u8bed\u6cd5\u5f62\u5f0f\u4e0a\u770b\uff0c\u6210\u5458\u53d8\u91cf\u662f\u5c5e\u4e8e\u7c7b\u7684\uff0c\u800c\u5c40\u90e8\u53d8\u91cf\u662f\u5728\u4ee3\u7801\u5757\u6216\u65b9\u6cd5\u4e2d\u5b9a\u4e49\u7684\u53d8\u91cf\u6216\u662f\u65b9\u6cd5\u7684\u53c2\u6570\uff1b\u6210\u5458\u53d8\u91cf\u53ef\u4ee5\u88ab public,private,static \u7b49\u4fee\u9970\u7b26\u6240\u4fee\u9970\uff0c\u800c\u5c40\u90e8\u53d8\u91cf\u4e0d\u80fd\u88ab\u8bbf\u95ee\u63a7\u5236\u4fee\u9970\u7b26\u53ca static \u6240\u4fee\u9970\uff1b\u4f46\u662f\uff0c\u6210\u5458\u53d8\u91cf\u548c\u5c40\u90e8\u53d8\u91cf\u90fd\u80fd\u88ab final \u6240\u4fee\u9970\u3002<br \/>\n<strong>\u5b58\u50a8\u65b9\u5f0f<\/strong>\uff1a\u4ece\u53d8\u91cf\u5728\u5185\u5b58\u4e2d\u7684\u5b58\u50a8\u65b9\u5f0f\u6765\u770b\uff0c\u5982\u679c\u6210\u5458\u53d8\u91cf\u662f\u4f7f\u7528 static \u4fee\u9970\u7684\uff0c\u90a3\u4e48\u8fd9\u4e2a\u6210\u5458\u53d8\u91cf\u662f\u5c5e\u4e8e\u7c7b\u7684\uff0c\u5982\u679c\u6ca1\u6709\u4f7f\u7528 static \u4fee\u9970\uff0c\u8fd9\u4e2a\u6210\u5458\u53d8\u91cf\u662f\u5c5e\u4e8e\u5b9e\u4f8b\u7684\u3002\u800c\u5bf9\u8c61\u5b58\u5728\u4e8e\u5806\u5185\u5b58\uff0c\u5c40\u90e8\u53d8\u91cf\u5219\u5b58\u5728\u4e8e\u6808\u5185\u5b58\u3002<br \/>\n<strong>\u751f\u5b58\u65f6\u95f4<\/strong>\uff1a\u4ece\u53d8\u91cf\u5728\u5185\u5b58\u4e2d\u7684\u751f\u5b58\u65f6\u95f4\u4e0a\u770b\uff0c\u6210\u5458\u53d8\u91cf\u662f\u5bf9\u8c61\u7684\u4e00\u90e8\u5206\uff0c\u5b83\u968f\u7740\u5bf9\u8c61\u7684\u521b\u5efa\u800c\u5b58\u5728\uff0c\u800c\u5c40\u90e8\u53d8\u91cf\u968f\u7740\u65b9\u6cd5\u7684\u8c03\u7528\u800c\u81ea\u52a8\u751f\u6210\uff0c\u968f\u7740\u65b9\u6cd5\u7684\u8c03\u7528\u7ed3\u675f\u800c\u6d88\u4ea1\u3002<br \/>\n<strong>\u9ed8\u8ba4\u503c<\/strong>\uff1a\u4ece\u53d8\u91cf\u662f\u5426\u6709\u9ed8\u8ba4\u503c\u6765\u770b\uff0c\u6210\u5458\u53d8\u91cf\u5982\u679c\u6ca1\u6709\u88ab\u8d4b\u521d\u59cb\u503c\uff0c\u5219\u4f1a\u81ea\u52a8\u4ee5\u7c7b\u578b\u7684\u9ed8\u8ba4\u503c\u800c\u8d4b\u503c\uff08\u4e00\u79cd\u60c5\u51b5\u4f8b\u5916:\u88ab final \u4fee\u9970\u7684\u6210\u5458\u53d8\u91cf\u4e5f\u5fc5\u987b\u663e\u5f0f\u5730\u8d4b\u503c\uff09\uff0c\u800c\u5c40\u90e8\u53d8\u91cf\u5219\u4e0d\u4f1a\u81ea\u52a8\u8d4b\u503c\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E6%88%90%E5%91%98%E5%8F%98%E9%87%8F%E6%9C%89%E9%BB%98%E8%AE%A4%E5%80%BC%EF%BC%9F\"><\/span>\u4e3a\u4ec0\u4e48\u6210\u5458\u53d8\u91cf\u6709\u9ed8\u8ba4\u503c\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>1\u3001\u5148\u4e0d\u8003\u8651\u53d8\u91cf\u7c7b\u578b\uff0c\u5982\u679c\u6ca1\u6709\u9ed8\u8ba4\u503c\u4f1a\u600e\u6837\uff1f\u53d8\u91cf\u5b58\u50a8\u7684\u662f\u5185\u5b58\u5730\u5740\u5bf9\u5e94\u7684\u4efb\u610f\u968f\u673a\u503c\uff0c\u7a0b\u5e8f\u8bfb\u53d6\u8be5\u503c\u8fd0\u884c\u4f1a\u51fa\u73b0\u610f\u5916\u3002<br \/>\n2\u3001\u9ed8\u8ba4\u503c\u6709\u4e24\u79cd\u8bbe\u7f6e\u65b9\u5f0f\uff1a\u624b\u52a8\u548c\u81ea\u52a8\uff0c\u6839\u636e\u7b2c\u4e00\u70b9\uff0c\u6ca1\u6709\u624b\u52a8\u8d4b\u503c\u4e00\u5b9a\u8981\u81ea\u52a8\u8d4b\u503c\u3002\u6210\u5458\u53d8\u91cf\u5728\u8fd0\u884c\u65f6\u53ef\u501f\u52a9\u53cd\u5c04\u7b49\u65b9\u6cd5\u624b\u52a8\u8d4b\u503c\uff0c\u800c\u5c40\u90e8\u53d8\u91cf\u4e0d\u884c\u3002<br \/>\n3\u3001\u5bf9\u4e8e\u7f16\u8bd1\u5668\uff08javac\uff09\u6765\u8bf4\uff0c\u5c40\u90e8\u53d8\u91cf\u6ca1\u8d4b\u503c\u5f88\u597d\u5224\u65ad\uff0c\u53ef\u4ee5\u76f4\u63a5\u62a5\u9519\u3002\u800c\u6210\u5458\u53d8\u91cf\u53ef\u80fd\u662f\u8fd0\u884c\u65f6\u8d4b\u503c\uff0c\u65e0\u6cd5\u5224\u65ad\uff0c\u8bef\u62a5\u201c\u6ca1\u9ed8\u8ba4\u503c\u201d\u53c8\u4f1a\u5f71\u54cd\u7528\u6237\u4f53\u9a8c\uff0c\u6240\u4ee5\u91c7\u7528\u81ea\u52a8\u8d4b\u9ed8\u8ba4\u503c\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E5%AD%97%E7%AC%A6%E5%9E%8B%E5%B8%B8%E9%87%8F%E5%92%8C%E5%AD%97%E7%AC%A6%E4%B8%B2%E5%B8%B8%E9%87%8F%E7%9A%84%E5%8C%BA%E5%88%AB\"><\/span>\u5b57\u7b26\u578b\u5e38\u91cf\u548c\u5b57\u7b26\u4e32\u5e38\u91cf\u7684\u533a\u522b?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u5f62\u5f0f <\/strong>: \u5b57\u7b26\u5e38\u91cf\u662f\u5355\u5f15\u53f7\u5f15\u8d77\u7684\u4e00\u4e2a\u5b57\u7b26\uff0c\u5b57\u7b26\u4e32\u5e38\u91cf\u662f\u53cc\u5f15\u53f7\u5f15\u8d77\u7684 0 \u4e2a\u6216\u82e5\u5e72\u4e2a\u5b57\u7b26\u3002<br \/>\n<strong>\u542b\u4e49 <\/strong>: \u5b57\u7b26\u5e38\u91cf\u76f8\u5f53\u4e8e\u4e00\u4e2a\u6574\u578b\u503c( ASCII \u503c),\u53ef\u4ee5\u53c2\u52a0\u8868\u8fbe\u5f0f\u8fd0\u7b97; \u5b57\u7b26\u4e32\u5e38\u91cf\u4ee3\u8868\u4e00\u4e2a\u5730\u5740\u503c(\u8be5\u5b57\u7b26\u4e32\u5728\u5185\u5b58\u4e2d\u5b58\u653e\u4f4d\u7f6e)\u3002<br \/>\n<strong>\u5360\u5185\u5b58\u5927\u5c0f<\/strong>\uff1a\u5b57\u7b26\u5e38\u91cf\u53ea\u5360 2 \u4e2a\u5b57\u8282; \u5b57\u7b26\u4e32\u5e38\u91cf\u5360\u82e5\u5e72\u4e2a\u5b57\u8282\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E9%9D%99%E6%80%81%E6%96%B9%E6%B3%95%E4%B8%BA%E4%BB%80%E4%B9%88%E4%B8%8D%E8%83%BD%E8%B0%83%E7%94%A8%E9%9D%9E%E9%9D%99%E6%80%81%E6%88%90%E5%91%98\"><\/span>\u9759\u6001\u65b9\u6cd5\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u8c03\u7528\u975e\u9759\u6001\u6210\u5458?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>\u8fd9\u4e2a\u9700\u8981\u7ed3\u5408 JVM \u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u4e3b\u8981\u539f\u56e0\u5982\u4e0b\uff1a<\/strong><br \/>\n1\u3001\u9759\u6001\u65b9\u6cd5\u662f\u5c5e\u4e8e\u7c7b\u7684\uff0c\u5728\u7c7b\u52a0\u8f7d\u7684\u65f6\u5019\u5c31\u4f1a\u5206\u914d\u5185\u5b58\uff0c\u53ef\u4ee5\u901a\u8fc7\u7c7b\u540d\u76f4\u63a5\u8bbf\u95ee\u3002\u800c\u975e\u9759\u6001\u6210\u5458\u5c5e\u4e8e\u5b9e\u4f8b\u5bf9\u8c61\uff0c\u53ea\u6709\u5728\u5bf9\u8c61\u5b9e\u4f8b\u5316\u4e4b\u540e\u624d\u5b58\u5728\uff0c\u9700\u8981\u901a\u8fc7\u7c7b\u7684\u5b9e\u4f8b\u5bf9\u8c61\u53bb\u8bbf\u95ee\u3002<br \/>\n2\u3001\u5728\u7c7b\u7684\u975e\u9759\u6001\u6210\u5458\u4e0d\u5b58\u5728\u7684\u65f6\u5019\u9759\u6001\u65b9\u6cd5\u5c31\u5df2\u7ecf\u5b58\u5728\u4e86\uff0c\u6b64\u65f6\u8c03\u7528\u5728\u5185\u5b58\u4e2d\u8fd8\u4e0d\u5b58\u5728\u7684\u975e\u9759\u6001\u6210\u5458\uff0c\u5c5e\u4e8e\u975e\u6cd5\u64cd\u4f5c\u3002<\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E9%87%8D%E8%BD%BD%E5%92%8C%E9%87%8D%E5%86%99%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%EF%BC%9F\"><\/span>\u91cd\u8f7d\u548c\u91cd\u5199\u6709\u4ec0\u4e48\u533a\u522b\uff1f<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><img decoding=\"async\" src=\"https:\/\/yingjun.run\/wp-content\/uploads\/2025\/07\/image-1752301602622.png\" alt=\"file\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Java\u8bed\u8a00\u6709\u54ea\u4e9b\u7279\u70b9 \u7b80\u5355\u6613\u5b66\uff08\u8bed\u6cd5\u7b80\u5355\uff0c\u4e0a\u624b\u5bb9\u6613\uff09\uff1b\u9762\u5411\u5bf9\u8c61\uff08\u5c01\u88c5\uff0c\u7ee7\u627f\uff0c\u591a\u6001\uff09\uff1b \u5e73\u53f0\u65e0\u5173\u6027\uff08 Java \u865a\u62df\u673a\u5b9e\u73b0\u5e73\u53f0\u65e0\u5173\u6027\uff09\uff1b \u652f\u6301\u591a\u7ebf\u7a0b\uff08 C++ \u8bed\u8a00\u6ca1\u6709\u5185\u7f6e\u7684\u591a\u7ebf\u7a0b\u673a\u5236\uff0c\u56e0\u6b64\u5fc5\u987b\u8c03\u7528\u64cd\u4f5c\u7cfb\u7edf\u7684\u591a\u7ebf\u7a0b\u529f\u80fd\u6765\u8fdb\u884c\u591a\u7ebf\u7a0b\u7a0b\u5e8f\u8bbe\u8ba1\uff0c\u800c Java \u8bed\u8a00\u5374\u63d0\u4f9b\u4e86\u591a\u7ebf\u7a0b\u652f\u6301\uff09\uff1b \u53ef\u9760\u6027\uff08\u5177\u5907\u5f02\u5e38\u5904\u7406\u548c\u81ea\u52a8\u5185\u5b58\u7ba1\u7406\u673a\u5236\uff09\uff1b \u5b89\u5168\u6027\uff08Java \u8bed\u8a00\u672c\u8eab\u7684\u8bbe\u8ba1\u5c31\u63d0\u4f9b\u4e86\u591a\u91cd\u5b89\u5168\u9632\u62a4\u673a\u5236\u5982\u8bbf\u95ee\u6743\u9650\u4fee\u9970\u7b26\u3001 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":100,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-99","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/99","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/comments?post=99"}],"version-history":[{"count":8,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/99\/revisions"}],"predecessor-version":[{"id":123,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/posts\/99\/revisions\/123"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/media\/100"}],"wp:attachment":[{"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/media?parent=99"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/categories?post=99"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yingjun.run\/index.php\/wp-json\/wp\/v2\/tags?post=99"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}