{"id":203174,"date":"2025-05-22T09:58:57","date_gmt":"2025-05-22T01:58:57","guid":{"rendered":"https:\/\/server.hk\/cnblog\/203174\/"},"modified":"2025-05-22T09:58:57","modified_gmt":"2025-05-22T01:58:57","slug":"item-%e6%9b%b4%e5%96%9c%e6%ac%a2%e5%8e%9f%e5%a7%8b%e7%b1%bb%e5%9e%8b%e8%80%8c%e4%b8%8d%e6%98%af%e6%89%93%e5%8c%85%e7%9a%84%e5%8e%9f%e5%a7%8b%e7%b1%bb%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/203174\/","title":{"rendered":"Item \u66f4\u559c\u6b22\u539f\u59cb\u7c7b\u578b\u800c\u4e0d\u662f\u6253\u5305\u7684\u539f\u59cb\u7c7b\u578b"},"content":{"rendered":"<p><b><\/b>     <\/p>\n<h1>Item \u66f4\u559c\u6b22\u539f\u59cb\u7c7b\u578b\u800c\u4e0d\u662f\u6253\u5305\u7684\u539f\u59cb\u7c7b\u578b<\/h1>\n<p><span style=\"cursor: pointer\"><i><\/i>\u6536\u85cf<\/span>    <\/p>\n<p>\u201c\u7eb5\u6709\u75be\u98ce\u6765\uff0c\u4eba\u751f\u4e0d\u8a00\u5f03\u201d\uff0c\u8fd9\u53e5\u8bdd\u9001\u7ed9\u6b63\u5728\u5b66\u4e60<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u6587\u7ae0<\/span>\u7684\u670b\u53cb\u4eec\uff0c\u4e5f\u5e0c\u671b\u5728\u9605\u8bfb\u672c\u6587<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u300aItem \u66f4\u559c\u6b22\u539f\u59cb\u7c7b\u578b\u800c\u4e0d\u662f\u6253\u5305\u7684\u539f\u59cb\u7c7b\u578b\u300b<\/span>\u540e\uff0c\u80fd\u591f\u771f\u7684\u5e2e\u52a9\u5230\u5927\u5bb6\u3002\u6211\u4e5f\u4f1a\u5728\u540e\u7eed\u7684\u6587\u7ae0\u4e2d\uff0c\u9646\u7eed\u66f4\u65b0<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\">\u6587\u7ae0<\/span>\u76f8\u5173\u7684\u6280\u672f\u6587\u7ae0\uff0c\u6709\u597d\u7684\u5efa\u8bae\u6b22\u8fce\u5927\u5bb6\u5728\u8bc4\u8bba\u7559\u8a00\uff0c\u975e\u5e38\u611f\u8c22\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241031\/173035839967232c7f81f6c.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u539f\u59cb\u7c7b\u578b\u4e0e\u539f\u59cb\u7c7b\u578b\u6253\u5305\u7684\u539f\u59cb\u7c7b\u578b<\/strong><\/p>\n<ul>\n<li>\u57fa\u672c\u7c7b\u578b\uff1aint\u3001double\u3001boolean \u7b49<\/li>\n<li>\u538b\u7f29\u539f\u59cb\u7c7b\u578b\uff1a\u6574\u6570\u3001\u53cc\u7cbe\u5ea6\u3001\u5e03\u5c14\u503c\u7b49<\/li>\n<li>java \u6709\u53cc\u91cd\u7c7b\u578b\u7cfb\u7edf\uff1a\u539f\u59cb\u7c7b\u578b\u548c\u5f15\u7528\u7c7b\u578b\uff08\u5bf9\u8c61\uff09\u3002<\/li>\n<li>\u6bcf\u79cd\u57fa\u672c\u7c7b\u578b\u90fd\u6709\u5bf9\u5e94\u7684\u5305\u88c5\u7c7b\u3002<\/li>\n<\/ul>\n<p><strong>\u4e3b\u8981\u533a\u522b<\/strong><\/p>\n<ul>\n<li>\n<p>\u8eab\u4efd\u4e0e\u8eab\u4efd\u4ef7\u503c\uff1a<br \/><strong>\u539f\u8bed\uff1a<\/strong>\u5b83\u4eec\u6ca1\u6709\u8eab\u4efd\uff1b\u5177\u6709\u76f8\u540c\u503c\u7684\u4e24\u4e2a\u57fa\u5143\u59cb\u7ec8\u76f8\u7b49\u3002<br \/><strong>\u6253\u5305\uff1a<\/strong>\u5b83\u4eec\u662f\u5bf9\u8c61\uff0c\u6709\u8eab\u4efd\uff1b\u4e24\u4e2a\u5bf9\u8c61\u53ef\u4ee5\u5177\u6709\u76f8\u540c\u7684\u503c\u4f46\u4e0d\u540c\u7684\u6807\u8bc6\u3002<\/p>\n<\/li>\n<li>\n<p>\u7a7a\u503c\uff1a<br \/><strong>\u57fa\u5143\uff1a<\/strong> \u59cb\u7ec8\u6709\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff08\u4f8b\u5982\uff0cint \u4e3a 0\uff09\u3002<br \/><strong>\u6253\u5305\uff1a<\/strong>\u53ef\u80fd\u4e3anull\uff0c\u5982\u679c\u5904\u7406\u4e0d\u5f53\u53ef\u80fd\u4f1a\u5bfc\u81f4nullpointerexception\u5f02\u5e38\u3002<\/p>\n<\/li>\n<li>\n<p>\u8868\u73b0\uff1a<br \/><strong>\u539f\u8bed\uff1a<\/strong>\u5728\u65f6\u95f4\u548c\u7a7a\u95f4\u4e0a\u66f4\u9ad8\u6548\u3002<br \/><strong>\u6253\u5305\uff1a<\/strong> \u7531\u4e8e\u521b\u5efa\u989d\u5916\u5bf9\u8c61\u800c\u5f15\u5165\u5f00\u9500\u3002<\/p>\n<\/li>\n<\/ul>\n<p><strong>\u6df7\u5408\u57fa\u5143\u548c\u5305\u65f6\u7684\u5e38\u89c1\u95ee\u9898<\/strong><\/p>\n<ul>\n<li>1.\u6bd4\u8f83\u8eab\u4efd\u800c\u4e0d\u662f\u4ef7\u503c<\/li>\n<li>\u5f53\u6bd4\u8f83\u4f7f\u7528 == \u6253\u5305\u7684\u5bf9\u8c61\u65f6\uff0c\u60a8\u6bd4\u8f83\u7684\u662f\u5bf9\u8c61\u5f15\u7528\uff0c\u800c\u4e0d\u662f\u503c\u3002\u8fd9\u53ef\u80fd\u4f1a\u5bfc\u81f4\u610f\u60f3\u4e0d\u5230\u7684\u7ed3\u679c\u3002<\/li>\n<\/ul>\n<p>\u6709\u95ee\u9898\u7684\u793a\u4f8b\uff1a<\/p>\n<pre>comparator&lt;integer&gt; naturalorder = (i, j) -&gt; (i &lt; j) ? -1 : (i == j ? 0 : 1);\n\n<\/pre>\n<p><strong>\u95ee\u9898\uff1a<\/strong> i == j \u6bd4\u8f83\u6bd4\u8f83\u5f15\u7528\uff0c\u800c\u4e0d\u662f\u503c\u3002<br \/> \u4e0d\u6b63\u786e\u7684\u884c\u4e3a\uff1anaturalorder.compare(new integer(42), new integer(42)) \u8fd4\u56de 1 \u800c\u4e0d\u662f 0\u3002<\/p>\n<p><strong>\u89e3\u51b3\u65b9\u6848\uff1a<\/strong><br \/> \u4f7f\u7528 integer \u7c7b\u7684 compareto \u65b9\u6cd5\u6216\u5b9e\u7528\u65b9\u6cd5\u3002<\/p>\n<pre>comparator&lt;integer&gt; naturalorder = integer::compare;\n\n<\/pre>\n<p>\u6216\u8005\uff0c\u7ea0\u6b63\u539f\u59cb\u6bd4\u8f83\u5668\uff1a<\/p>\n<pre>comparator&lt;integer&gt; naturalorder = (iboxed, jboxed) -&gt; {\n    int i = iboxed;\n    int j = jboxed;\n    return (i &lt; j) ? -1 : ((i == j) ? 0 : 1);\n};\n\n<\/pre>\n<p><strong>2\u3002\u81ea\u52a8\u62c6\u7bb1\u548c nullpointerexception<\/strong><br \/> \u5f53\u4f7f\u7528\u53ef\u4ee5\u4e3a null \u7684\u6253\u5305\u7c7b\u578b\u65f6\uff0c\u5982\u679c\u5bf9\u8c61\u4e3a null\uff0c\u81ea\u52a8\u62c6\u7bb1\u53ef\u80fd\u4f1a\u5f15\u53d1\u5f02\u5e38\u3002<\/p>\n<p>\u6709\u95ee\u9898\u7684\u793a\u4f8b\uff1a<\/p>\n<pre>integer i = null;\nif (i == 42) {\n    system.out.println(\"inacredit\u00e1vel\");\n}\n\n<\/pre>\n<p><strong>\u95ee\u9898\uff1a<\/strong> i \u4e3a\u7a7a\uff1b\u4e0e 42 \u6bd4\u8f83\u65f6\uff0c\u4f1a\u53d1\u751f null \u81ea\u52a8\u62c6\u7bb1\uff0c\u5bfc\u81f4 nullpointerexception\u3002<br \/><strong>\u89e3\u51b3\u65b9\u6848\uff1a<\/strong>\u5c3d\u53ef\u80fd\u4f7f\u7528\u539f\u59cb\u7c7b\u578b\u3002<\/p>\n<pre>int i = 0;\nif (i == 42) {\n    system.out.println(\"inacredit\u00e1vel\");\n}\n\n<\/pre>\n<p><strong>3\u3002\u7531\u4e8e\u81ea\u52a8\u88c5\u7bb1\/\u62c6\u7bb1\u800c\u5bfc\u81f4\u6027\u80fd\u4e0b\u964d<\/strong><br \/> \u5728\u5bc6\u96c6\u578b\u64cd\u4f5c\u4e2d\u65e0\u610f\u4e2d\u4f7f\u7528\u5305\u88c5\u7c7b\u578b\u53ef\u80fd\u4f1a\u7531\u4e8e\u81ea\u52a8\u88c5\u7bb1\u548c\u4e0d\u5fc5\u8981\u7684\u5bf9\u8c61\u521b\u5efa\u800c\u5bfc\u81f4\u6027\u80fd\u4e0b\u964d\u3002<\/p>\n<p>\u6709\u95ee\u9898\u7684\u793a\u4f8b\uff1a<\/p>\n<pre>long sum = 0l;\nfor (long i = 0; i &lt;= integer.max_value; i++) {\n    sum += i;\n}\nsystem.out.println(sum);\n\n<\/pre>\n<p><strong>\u95ee\u9898\uff1a<\/strong> sum \u662f\u4e00\u4e2a\u538b\u7f29\u7684 long\uff1b\u5728\u6bcf\u6b21\u8fed\u4ee3\u4e2d\uff0c\u90fd\u4f1a\u53d1\u751f\u81ea\u52a8\u88c5\u7bb1\/\u62c6\u7bb1\u3002<\/p>\n<p>\u5f71\u54cd\uff1a\u4ee3\u7801\u901f\u5ea6\u53d8\u6162\u5e76\u4e14\u5185\u5b58\u4f7f\u7528\u8fc7\u591a\u3002<br \/><strong>\u89e3\u51b3\u65b9\u6848\uff1a<\/strong><br \/> \u5728\u5bc6\u96c6\u64cd\u4f5c\u4e2d\u5bf9\u5c40\u90e8\u53d8\u91cf\u4f7f\u7528\u539f\u59cb\u7c7b\u578b\u3002<\/p>\n<pre>long sum = 0L;\nfor (long i = 0; i &lt;= Integer.MAX_VALUE; i++) {\n    sum += i;\n}\nSystem.out.println(sum);\n\n<\/pre>\n<p><strong>\u4f55\u65f6\u4f7f\u7528\u5c01\u88c5\u7c7b\u578b<\/strong><\/p>\n<ul>\n<li>\u96c6\u5408\uff1a\u4e0d\u80fd\u5728\u6cdb\u578b\u96c6\u5408\uff08\u4f8b\u5982\u5217\u8868\uff09\u4e2d\u4f7f\u7528\u539f\u59cb\u7c7b\u578b\u3002<\/li>\n<li>\u6cdb\u578b\u53c2\u6570\uff1a\u6cdb\u578b\u7c7b\u578b\u4e0d\u652f\u6301\u539f\u59cb\u7c7b\u578b\uff08\u4f8b\u5982threadlocal\uff09\u3002<\/li>\n<li>\u9700\u8981\u5bf9\u8c61\u7684 api\uff1a\u67d0\u4e9b api \u9700\u8981\u5bf9\u8c61\u800c\u4e0d\u662f\u539f\u59cb\u7c7b\u578b\u3002<\/li>\n<\/ul>\n<p><strong>\u826f\u597d\u5b9e\u8df5<\/strong><\/p>\n<ul>\n<li>\u9996\u9009\u539f\u59cb\u7c7b\u578b\uff1a\u53ea\u8981\u6709\u53ef\u80fd\uff0c\u5c31\u4f7f\u7528\u539f\u59cb\u7c7b\u578b\u4ee5\u5b9e\u73b0\u7b80\u5355\u6027\u548c\u6548\u7387\u3002<\/li>\n<li>\u5c0f\u5fc3\u81ea\u52a8\u88c5\u7bb1\/\u62c6\u7bb1\uff1a\u81ea\u52a8\u88c5\u7bb1\u53ef\u4ee5\u51cf\u5c11\u5197\u957f\uff0c\u4f46\u53ef\u80fd\u4f1a\u5f15\u5165\u5fae\u5999\u7684\u9519\u8bef\u3002<\/li>\n<li>\u907f\u514d\u5728 wrapped \u4e2d\u4e0e == \u8fdb\u884c\u6bd4\u8f83\uff1a\u4f7f\u7528 equals() \u7b49\u65b9\u6cd5\u6216\u6bd4\u8f83\u5c55\u5f00\u7684\u503c\u3002<\/li>\n<li>\u68c0\u67e5\u7a7a\u503c\uff1a\u4f7f\u7528\u6253\u5305\u7c7b\u578b\u65f6\uff0c\u8bf7\u6ce8\u610f\u5b83\u4eec\u53ef\u80fd\u4e3a\u7a7a\u5e76\u5bfc\u81f4 nullpointerexception\u3002<\/li>\n<\/ul>\n<p><strong>\u603b\u7ed3<\/strong><br \/><strong>\u539f\u59cb\u7c7b\u578b\uff1a<\/strong><br \/> \u66f4\u7b80\u5355\u3001\u66f4\u5feb\u3002<br \/> \u5b83\u4eec\u4e0d\u80fd\u4e3a\u7a7a\u3002<br \/> \u4ed6\u4eec\u6ca1\u6709\u8eab\u4efd\uff08\u53ea\u6709\u4ef7\u503c\uff09\u3002<\/p>\n<p>\u5305\u88c5\u7c7b\u578b\uff1a<br \/> \u5728\u96c6\u5408\u548c\u901a\u7528 api \u4e2d\u4f7f\u7528\u65f6\u9700\u8981\u3002<br \/> \u5b83\u4eec\u53ef\u4ee5\u4e3a\u7a7a\u3002<br \/> \u4ed6\u4eec\u6709\u5bf9\u8c61\u8eab\u4efd\u3002<\/p>\n<p>\u4eca\u5929\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff1b\u5173\u4e8e\u6587\u7ae0\u7684\u6280\u672f\u77e5\u8bc6\u6211\u4eec\u4f1a\u4e00\u70b9\u70b9\u6df1\u5165\u4ecb\u7ecd\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u4e00\u8d77\u5b66\u4e60\u7f16\u7a0b~<\/p>\n<p>      \u7248\u672c\u58f0\u660e \u672c\u6587\u8f6c\u8f7d\u4e8e\uff1adev.to \u5982\u6709\u4fb5\u72af\uff0c\u8bf7\u8054\u7cfb\u5220\u9664<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Item \u66f4\u559c\u6b22\u539f\u59cb\u7c7b\u578b\u800c\u4e0d\u662f\u6253&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-203174","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203174","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=203174"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203174\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=203174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=203174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=203174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}