{"id":2008,"date":"2020-08-11T06:51:13","date_gmt":"2020-08-10T22:51:13","guid":{"rendered":"http:\/\/admin.evshou.com\/?p=2008"},"modified":"2020-08-11T09:28:56","modified_gmt":"2020-08-11T01:28:56","slug":"2020java%e6%95%99%e7%a8%8b%ef%bc%9a%e9%9d%a2%e5%90%91%e5%af%b9%e8%b1%a1%e4%b8%89%e5%a4%a7%e7%89%b9%e6%80%a7%e4%b9%8b%e5%a4%9a%e6%80%81","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=2008","title":{"rendered":"2020java\u6559\u7a0b\uff1a\u9762\u5411\u5bf9\u8c61\u4e09\u5927\u7279\u6027\u4e4b\u591a\u6001"},"content":{"rendered":"

\u9762\u5411\u5bf9\u8c61\u4e09\u5927\u7279\u6027\u4e4b\u591a\u6001<\/h3>\n

\u751f\u6d3b\u4e2d\u7684\u4eba\u7269\u89c6\u89d2
\n\u751f\u6d3b\u4e2d\uff0c\u4e0d\u540c\u4eba\u7269\u89d2\u8272\u770b\u5f85\u540c\u4e00\u4e2a\u5bf9\u8c61\u7684\u89c6\u89d2\u4e0d\u540c\uff0c\u5173\u6ce8\u70b9\u4e5f\u4e0d\u540c<\/p>\n

\u6bd4\u5982\u5b66\u751f\u5c0f\u660e
\n\u5728\u7236\u6bcd\u773c\u91cc\u4ed6\u662f\u513f\u5b50\uff0c\u5728\u7237\u7237\u773c\u91cc\u4ed6\u662f\u5b59\u5b50
\n\u5728\u8001\u5e08\u773c\u91cc\u4ed6\u662f\u5b66\u751f\uff0c\u5728\u540c\u5b66\u773c\u91cc\u4ed6\u662f\u540c\u5b66<\/p>\n

\u751f\u6d3b\u4e2d\u7684\u591a\u6001
\n\u5982\u679c\u4f60\u770b\u89c1 \u8725\u8734 \u4f60\u4f1a\u8bf4 \u5b83\u662f\u4ec0\u4e48\uff1f
\n\u8725\u8734\uff1f\u52a8\u7269\uff1f\u722c\u866b\uff1f
\n\u751f\u6d3b\u4e2d\u7684\u591a\u6001\u662f\u6307`\u5ba2\u89c2\u4e8b\u7269\u5728\u4eba\u8111\u4e2d\u7684\u4e3b\u89c2\u53cd\u5e94`
\n\u4e3b\u89c2\u610f\u8bc6\u4e0a\u7684\u7c7b\u522b\u4e0e\u5ba2\u89c2\u5b58\u5728\u7684\u5bf9\u8c61\u5177\u6709 \u201cis a\u201d \u5173\u7cfb\u65f6\uff0c\u5373\u5f62\u6210\u591a\u6001<\/p>\n

\u7a0b\u5e8f\u4e2d\u7684\u591a\u6001
\n\u6982\u5ff5\uff1a\u7236\u7c7b\u5f15\u7528\u6307\u5411\u5b50\u7c7b\u5bf9\u8c61\uff0c\u4ece\u800c\u4ea7\u751f\u591a\u79cd\u5f62\u6001
\n\u7236\u7c7b\u5bf9\u8c61(\u5f15\u7528\u7c7b\u578b)Animal a=new Dog();\u5b50\u7c7b\u5bf9\u8c61(\u5bf9\u8c61\u7c7b\u578b)
\n\u4e8c\u8005\u5177\u6709\u76f4\u63a5\u6216\u95f4\u63a5\u7684\u7ee7\u627f\u5173\u7cfb\u65f6\uff0c\u7236\u7c7b\u5f15\u7528\u53ef\u6307\u5411\u5b50\u7c7b\u5bf9\u8c61\uff0c\u5373\u5f62\u6210\u591a\u6001\u3002
\n\u7236\u7c7b\u5f15\u7528\u4ec5\u53ef\u8c03\u7528\u7236\u7c7b\u6240\u58f0\u660e\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u4e0d\u53ef\u8c03\u7528\u5b50\u7c7b\u72ec\u6709\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/p>\n

\u591a\u6001\u4e2d\u7684\u65b9\u6cd5\u8986\u76d6
\n\u5982\u679c\u5b50\u7c7b\u4e2d\u8986\u76d6\u4e86\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\uff0c\u4ee5\u7236\u7c7b\u578b\u5f15\u7528\u8c03\u7528\u6b64\u65b9\u6cd5\u65f6\uff0c\u4f18\u5148\u6267\u884c\u7236\u7c7b\u8fd8\u662f\u5b50\u7c7b\u4e2d\u7684\u65b9\u6cd5\uff1f
\n\u5b9e\u9645\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u4f9d\u65e7\u9075\u5faa\u8986\u76d6\u539f\u5219\uff0c\u5982\u679c\u5b50\u7c7b\u8986\u76d6\u4e86\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\uff0c\u5219\u6267\u884c\u5b50\u7c7b\u4e2d\u8986\u76d6\u540e\u7684\u65b9\u6cd5\uff0c\u5426\u5219\u6267\u884c\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\u3002<\/p>\n

\u5411\u4e0a\u8f6c\u578b\u4ee5\u53ca\u5411\u4e0b\u8f6c\u578b<\/p>\n

public class demos{\r\n    public static void main(String[] args) {\r\n        \/\/\u7236\u7c7b\u5f15\u7528\u4e2d\u4fdd\u5b58\u771f\u5b9e\u5b50\u7c7b\u5bf9\u8c61\u79f0\u4e3a\u5411\u4e0a\u8f6c\u578b(\u88c5\u7bb1)\r\n        Animal a=new Dog();\r\n        a.feed();\r\n        \/\/a.run();ERROR\uff0c\u7236\u7c7b\u6ca1\u6709\u5b9a\u4e49run\u65b9\u6cd5\uff0c\u65e0\u6cd5\u8c03\u7528\r\n        \/\/\u5411\u4e0b\u8f6c\u578b\uff0c\u8f6c\u56de\u81ea\u8eab\u7c7b\u578b\r\n        Dog d=(Dog)a;\r\n        d.feed();\r\n        d.run();\r\n    }\r\n}\r\nclass Animal{\r\n    public void feed(){\r\n        System.out.println(\"Animal feed\u65b9\u6cd5\");\r\n    }\r\n}\r\nclass Dog extends Animal{\r\n    public void feed() {\r\n        System.out.println(\"Dog\u7684 feed\u65b9\u6cd5\");\r\n    }\r\n    public void run(){\r\n        System.out.println(\"Dog\u7684 run\u65b9\u6cd5\");\r\n    }\r\n}<\/pre>\n
instanceof\u5173\u952e\u5b57<\/p>\n
public class demos{\r\n    public static void main(String[] args) {\r\n        Animal a=new Dog();\r\n        \/\/\u5411\u4e0b\u8f6c\u578b\u524d\uff0c\u5e94\u5224\u65ad\u5f15\u7528\u4e2d\u7684\u5bf9\u8c61\u771f\u5b9e\u7c7b\u578b\r\n        \/\/ \u4fdd\u8bc1\u7c7b\u578b\u8f6c\u6362\u7684\u6b63\u786e\u6027\r\n        \/\/\u5173\u952e\u5b57 instanceof\r\n        \/\/\u8bed\u6cd5  \u5f15\u7528 instanceof  \u7c7b\u578b\r\n        if(a instanceof Cat){\r\n            Cat c=(Cat)a;\r\n            c.feed();\r\n        }else if(a instanceof Dog){\r\n            Dog d=(Dog)a;\r\n            d.feed();\r\n        }\r\n    }\r\n}\r\nclass Animal{\r\n    public void feed(){\r\n        System.out.println(\"Animal feed\u65b9\u6cd5\");\r\n    }\r\n}\r\nclass Dog extends Animal{\r\n    public void feed() {\r\n        System.out.println(\"Dog\u7684 feed\u65b9\u6cd5\");\r\n    }\r\n}\r\nclass Cat extends Animal{\r\n    public void feed(){\r\n        System.out.println(\"Cat\u7684 feed\u65b9\u6cd5\");\r\n    }\r\n}<\/pre>\n
\u603b\u7ed3<\/p>\n
\u591a\u6001\u7684\u4e24\u79cd\u5e94\u7528\u573a\u666f\uff1a
\n1.\u4f7f\u7528\u7236\u7c7b\u4f5c\u4e3a\u65b9\u6cd5\u5f62\u53c2 \uff0c\u5b9e\u73b0\u591a\u6001
\n1.1\u8c03\u7528\u65b9\u6cd5\u65f6\uff0c\u53ef\u4f20\u9012\u7684\u5b9e\u53c2\u7c7b\u578b\u5305\u62ec\uff1a\u672c\u7c7b\u578b\u5bf9\u8c61+ + \u5176\u6240\u6709\u7684\u5b50\u7c7b\u5bf9\u8c61<\/p>\n
2.\u4f7f\u7528\u7236\u7c7b\u4f5c\u4e3a\u65b9\u6cd5\u8fd4\u56de\u503c\uff0c\u5b9e\u73b0\u591a\u6001
\n2.1\u8c03\u7528\u65b9\u6cd5\u540e\uff0c\u53ef\u5f97\u5230\u7684\u7ed3\u679c\u7c7b\u578b\u5305\u62ec\uff1a\u672c\u7c7b\u578b\u5bf9\u8c61+ + \u5176\u6240\u6709\u7684\u5b50\u7c7b\u5bf9\u8c61<\/p>\n
\u591a\u6001\u7684\u4f5c\u7528\uff1a
\n\u5c4f\u853d\u5b50\u7c7b\u95f4\u7684\u5dee\u5f02;\u00a0\u7075\u6d3b\u3001\u8026\u5408\u5ea6\u4f4e<\/p>\n","protected":false},"excerpt":{"rendered":"
\u9762\u5411\u5bf9\u8c61\u4e09\u5927\u7279\u6027\u4e4b\u591a\u6001 \u751f\u6d3b\u4e2d\u7684\u4eba\u7269\u89c6\u89d2 \u751f\u6d3b\u4e2d\uff0c\u4e0d\u540c\u4eba\u7269\u89d2\u8272\u770b\u5f85\u540c\u4e00\u4e2a\u5bf9\u8c61\u7684\u89c6\u89d2\u4e0d\u540c\uff0c\u5173\u6ce8\u70b9\u4e5f\u4e0d\u540c \u6bd4\u5982\u5b66\u751f […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-2008","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2008","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2008"}],"version-history":[{"count":6,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2008\/revisions"}],"predecessor-version":[{"id":2015,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2008\/revisions\/2015"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2008"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2008"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2008"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}