Record Patterns \u7b2c\u4e00\u6b21\u53d1\u5e03\u9884\u89c8\u662f\u5728JDK 19\u3001\u968f\u540e\u53c8\u5728JDK 20\u4e2d\u8fdb\u884c\u4e86\u5b8c\u5584\u3002\u73b0\u5728\uff0cJava 21\u5f00\u59cb\u6b63\u5f0f\u63a8\u51fa\u8be5\u7279\u6027\u4f18\u5316\u3002\u4e0b\u9762\u6211\u4eec\u901a\u8fc7\u4e00\u4e2a\u4f8b\u5b50\u6765\u7406\u89e3\u8fd9\u4e2a\u65b0\u7279\u6027\u3002<\/p>\n
record Point(int x, int y) {}\n\nstatic void printSum(Object obj) {\n if (obj instanceof Point p) {\n int x = p.x();\n int y = p.y();\n System.out.println(x+y);\n }\n}<\/code><\/pre>\n\u4e0a\u8ff0\u4ee3\u7801\u4e2d\u5b9a\u4e49\u4e86\u4e00\u4e2a\u540d\u4e3aPoint\u7684record\u7c7b<\/a>\uff08Java 16\u4e2d\u7684\u65b0\u7279\u6027\uff09\uff0c\u5982\u679c\u6211\u4eec\u60f3\u8981\u83b7\u53d6\u3001\u64cd\u4f5c\u6216\u8005\u6253\u5370Point\u4e2d\u7684x\u548cy\u7684\u8bdd\u3002\u5c31\u4e0d\u5f97\u4e0d\u5148\u5b8c\u6210\u7c7b\u578b\u5224\u65ad\u548c\u7c7b\u578b\u8f6c\u6362\u3002\u6240\u4ee5\uff0c\u8fd9\u91cc\u4e3a\u4e86\u5b9e\u73b0x+y\u603b\u5171\u9700\u89814\u884c\u4ee3\u7801\u3002\u800c\u5728Java 21\u4e4b\u540e\uff0c\u53ea\u9700\u89812\u884c\u4ee3\u7801\u5c31\u80fd\u5b8c\u6210\uff1a<\/p>\nstatic void printSum(Object obj) {\n if (obj instanceof Point(int x, int y)) {\n System.out.println(x+y);\n }\n}<\/code><\/pre>\n\u53ef\u4ee5\u770b\u5230\uff0c\u7c7b\u578b\u5224\u65ad\u3001\u7c7b\u578b\u8f6c\u6362\u3001record\u503c\u7684\u7ed3\u6784\u90fd\u4e00\u6c14\u5475\u6210\u4e86\uff0c\u6240\u4ee5\u4ee3\u7801\u91cf\u5f97\u5230\u4e86\u7b80\u5316\u3002<\/p>\n
\u5d4c\u5957record\u7684\u89e3\u6784<\/h2>\n
\u5047\u8bbe\u6709\u4e0b\u9762\u4e00\u7ec4\u5d4c\u5957\u7684record\u7ed3\u6784\uff08WindowFrame<\/code>\u4e2d\u5305\u542b\u4e86Point<\/code>\u548cSize<\/code>\uff09\uff1a<\/p>\nrecord Size(int width, int height) { }\nrecord Point(int x, int y) { }\nrecord WindowFrame(Point origin, Size size) { }<\/code><\/pre>\n\u8fd9\u4e2a\u65f6\u5019\uff0c\u5982\u679c\u60f3\u8981\u8bbf\u95eeWindowFrame<\/code>\u4e2dSize<\/code>\u7684height\uff0c\u6839\u636e\u4e4b\u524d\u6848\u4f8b\u7684\u7406\u89e3\uff0c\u6211\u4eec\u53ef\u4ee5\u8fd9\u6837\u5199\uff1a<\/p>\nif (obj instanceof WindowFrame wf) {\n if (wf.size() != null) {\n System.out.println("Height: " + wf.size().height());\n }\n}<\/code><\/pre>\n\u597d\u50cf\u4e5f\u6ca1\u6709\u5f88\u7b80\u5355\uff0c\u4f46\u5b9e\u9645\u4e0a\u8fd8\u6709\u66f4\u7b80\u5355\u7684\u5199\u6cd5\uff0c\u56e0\u4e3arecord\u7684\u89e3\u6784\u662f\u53ef\u4ee5\u5d4c\u5957\u7684\uff0c\u76f4\u63a5\u8fd9\u6837\u4e00\u6b65\u5b8c\u6210\u5373\u53ef\uff1a<\/p>\n
if (obj instanceof WindowFrame(Point origin, Size(int width, int height))) {\n System.out.println("Height: " + height);\n}<\/code><\/pre>\n\u662f\u4e0d\u662f\u4e00\u4e0b\u611f\u53d7\u5230\u8fd9\u4e2a\u65b0\u7279\u6027\u7684\u5f3a\u5927\u4e86\uff1f\u5982\u679c\u60a8\u5b66\u4e60\u8fc7\u7a0b\u4e2d\u5982\u9047\u56f0\u96be\uff1f\u53ef\u4ee5\u52a0\u5165\u6211\u4eec\u8d85\u9ad8\u8d28\u91cf\u7684\u6280\u672f\u4ea4\u6d41\u7fa4<\/a>\uff0c\u53c2\u4e0e\u4ea4\u6d41\u4e0e\u8ba8\u8bba\uff0c\u66f4\u597d\u7684\u5b66\u4e60\u4e0e\u8fdb\u6b65\uff01\u53e6\u5916\uff0c\u4e0d\u8981\u8d70\u5f00\uff0c\u5173\u6ce8\u6211\uff01\u6301\u7eed\u66f4\u65b0Java\u65b0\u7279\u6027\u4e13\u680f<\/a>\uff01<\/p>\n\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u516c\u4f17\u53f7\uff1a\u7a0b\u5e8f\u733fDD\u3002\u7b2c\u4e00\u65f6\u95f4\u4e86\u89e3\u524d\u6cbf\u884c\u4e1a\u6d88\u606f\u3001\u5206\u4eab\u6df1\u5ea6\u6280\u672f\u5e72\u8d27\u3001\u83b7\u53d6\u4f18\u8d28\u5b66\u4e60\u8d44\u6e90<\/p><\/blockquote>\n