{"id":3978,"date":"2024-05-17T08:02:09","date_gmt":"2024-05-17T00:02:09","guid":{"rendered":"https:\/\/xinchewhd.com.cn\/index.php\/%e9%9d%a2%e8%af%95\/%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88equals%e5%92%8chashcode%e9%9c%80%e8%a6%81%e5%90%8c%e6%97%b6%e9%87%8d%e5%86%99%ef%bc%9f-2\/"},"modified":"2024-08-02T17:26:23","modified_gmt":"2024-08-02T09:26:23","slug":"%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88equals%e5%92%8chashcode%e9%9c%80%e8%a6%81%e5%90%8c%e6%97%b6%e9%87%8d%e5%86%99%ef%bc%9f-2","status":"publish","type":"post","link":"https:\/\/xinchewhd.com.cn\/index.php\/%e9%9d%a2%e8%af%95\/%e9%9d%a2%e8%af%95%e5%ae%98%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88equals%e5%92%8chashcode%e9%9c%80%e8%a6%81%e5%90%8c%e6%97%b6%e9%87%8d%e5%86%99%ef%bc%9f-2\/","title":{"rendered":"\u9762\u8bd5\u5b98\uff1a\u4e3a\u4ec0\u4e48equals()\u548chashCode()\u9700\u8981\u540c\u65f6\u91cd\u5199\uff1f"},"content":{"rendered":"
\n

\u5728 Java \u4e2d\uff0cequals()\u548c hashCode()\u65b9\u6cd5\u9700\u8981\u540c\u65f6\u91cd\u5199\u7684\u539f\u56e0\u6709\u4ee5\u4e0b\u51e0\u4e2a\uff1a<\/span><\/p>\n

1. \u786e\u4fdd\u5bf9\u8c61\u6bd4\u8f83\u7684\u4e00\u81f4\u6027<\/span><\/strong><\/p>\n

\u5f53\u91cd\u5199 equals()\u65b9\u6cd5\u65f6\uff0c\u60a8\u5b9a\u4e49\u4e86\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u76f8\u7b49\u6027\u7684\u89c4\u5219\u3002\u5982\u679c\u53ea\u91cd\u5199 equals()\u65b9\u6cd5\uff0c\u4f46\u672a\u91cd\u5199 hashCode()\u65b9\u6cd5\uff0c\u90a3\u4e48 Java \u9ed8\u8ba4\u4f7f\u7528\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\u4f5c\u4e3a\u54c8\u5e0c\u7801\u3002\u8fd9\u53ef\u80fd\u4f1a\u5bfc\u81f4\u4e0d\u4e00\u81f4\u7684\u6bd4\u8f83\u7ed3\u679c\uff0c\u56e0\u4e3a\u4e24\u4e2a\u5177\u6709\u76f8\u540c equals()\u7ed3\u679c\u7684\u5bf9\u8c61\u53ef\u80fd\u5177\u6709\u4e0d\u540c\u7684\u54c8\u5e0c\u7801\u3002<\/span><\/p>\n

2. \u4f18\u5316\u96c6\u5408\u548c\u6620\u5c04\u7684\u6027\u80fd<\/span><\/strong><\/p>\n

Java \u96c6\u5408\u548c\u6620\u5c04\u4f7f\u7528\u54c8\u5e0c\u8868\u6765\u5b58\u50a8\u5bf9\u8c61\u3002\u54c8\u5e0c\u8868\u4f9d\u8d56\u4e8e\u5bf9\u8c61\u7684\u54c8\u5e0c\u7801\u6765\u786e\u5b9a\u5bf9\u8c61\u7684\u5b58\u50a8\u4f4d\u7f6e\u3002\u5982\u679c\u53ea\u91cd\u5199 equals()\u65b9\u6cd5\uff0c\u4f46\u672a\u91cd\u5199 hashCode()\u65b9\u6cd5\uff0c\u90a3\u4e48\u5177\u6709\u76f8\u540c equals()\u7ed3\u679c\u7684\u5bf9\u8c61\u53ef\u80fd\u5b58\u50a8\u5728\u54c8\u5e0c\u8868\u4e2d\u7684\u4e0d\u540c\u4f4d\u7f6e\u3002\u8fd9\u4f1a\u964d\u4f4e\u96c6\u5408\u548c\u6620\u5c04\u7684\u6027\u80fd\uff0c\u56e0\u4e3a\u67e5\u627e\u5bf9\u8c61\u9700\u8981\u68c0\u67e5\u591a\u4e2a\u54c8\u5e0c\u8868\u6876\u3002<\/span><\/p>\n

3. \u9075\u5b88 Java \u6807\u51c6\u5e93\u7684\u7ea6\u5b9a<\/span><\/strong><\/p>\n

Java \u6807\u51c6\u5e93\u4e2d\u7684\u7c7b\u7684\u5927\u591a\u6570\u5b9e\u73b0\u90fd\u9075\u5faa\u4e00\u4e2a\u7ea6\u5b9a\uff0c\u5373\u5982\u679c\u4e24\u4e2a\u5bf9\u8c61\u76f8\u7b49\uff0c\u90a3\u4e48\u5b83\u4eec\u7684\u54c8\u5e0c\u7801\u4e5f\u76f8\u540c\u3002\u5982\u679c\u53ea\u91cd\u5199 equals()\u65b9\u6cd5\uff0c\u4f46\u672a\u91cd\u5199 hashCode()\u65b9\u6cd5\uff0c\u90a3\u4e48\u60a8\u7684\u7c7b\u5c06\u8fdd\u53cd\u6b64\u7ea6\u5b9a\u3002<\/span><\/p>\n

\u4e3e\u4f8b\u8bf4\u660e<\/span><\/strong><\/p>\n

\u5047\u8bbe\u6709\u4e00\u4e2aPerson\u7c7b\uff0c\u5176\u4e2d\u6709\u4e24\u4e2a\u5c5e\u6027name\u548cage\uff0c\u6211\u4eec\u91cd\u5199equals()\u65b9\u6cd5\u6765\u5224\u65ad\u4e24\u4e2aPerson\u5bf9\u8c61\u662f\u5426\u76f8\u7b49\uff1a<\/span><\/p>\n

\n
\n
public class Person {\n    private String name;\n    private int age;\n\n    public Person(String name, int age) {\n        this.name = name;\n        this.age = age;\n    }\n\n    @Override\n    public boolean equals(Object o) {\n        if (this == o) return true;\n        if (!(o instanceof Person)) return false;\n        Person person = (Person) o;\n        if (age != person.age) return false;\n        return name != null ? name.equals(person.name) : person.name == null;\n    }\n    \/\/ hashCode() method not overridden!\n}<\/pre>\n<\/div>\n<\/section>\n
\u5982\u679c\u6211\u4eec\u521b\u5efa\u4e24\u4e2a\u76f8\u540c\u5185\u5bb9\u7684Person\u5bf9\u8c61\u5e76\u5c1d\u8bd5\u5c06\u5b83\u4eec\u63d2\u5165\u5230HashSet\u4e2d\uff0c\u6211\u4eec\u671f\u671b\u96c6\u5408\u4e2d\u53ea\u6709\u4e00\u4e2a\u5143\u7d20\uff0c\u56e0\u4e3a\u4ed6\u4eec\u903b\u8f91\u4e0a\u662f\"\u76f8\u7b49\"\u7684\u3002\u4f46\u5982\u679c\u6211\u4eec\u6ca1\u6709\u91cd\u5199hashCode()\u65b9\u6cd5\uff0c\u5c31\u4f1a\u53d1\u751f\u4ee5\u4e0b\u60c5\u51b5\uff1a<\/span><\/p>\n
\n
HashSet<Person> people = new<\/span> HashSet<>();<\/span><\/code>\npeople.add<\/span>(new<\/span> Person(\"John\"<\/span>, 30<\/span>));<\/span><\/code>\npeople.add<\/span>(new<\/span> Person(\"John\"<\/span>, 30<\/span>));<\/span><\/code><\/code>\nSystem.out<\/span>.println(people.size()); \/\/ \u8fd9\u4f1a\u8f93\u51fa2\u800c\u4e0d\u662f\u9884\u671f\u76841<\/span><\/span><\/code><\/pre>\n<\/section>\n
\u7531\u4e8ehashCode()\u65b9\u6cd5\u672a\u88ab\u91cd\u5199\uff0c\u6bcf\u4e2aPerson\u5bf9\u8c61\u90fd\u4f1a\u6709\u4e00\u4e2a\u57fa\u4e8e\u5176\u5185\u5b58\u5730\u5740\u4e0d\u540c\u7684\u9ed8\u8ba4\u54c8\u5e0c\u7801\uff0c\u6240\u4ee5\u5373\u4f7fequals()\u65b9\u6cd5\u8868\u660e\u8fd9\u4e24\u4e2a\u5bf9\u8c61\u662f\u76f8\u7b49\u7684\uff0cHashSet\u4ecd\u4f1a\u628a\u5b83\u4eec\u89c6\u4e3a\u4e0d\u540c\u7684\u5143\u7d20\u52a0\u5165\u5230\u96c6\u5408\u4e2d\u3002<\/span><\/p>\n
\u8981\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u6211\u4eec\u5e94\u8be5\u6839\u636e\u540c\u6837\u7684\u5c5e\u6027\u91cd\u5199hashCode()\u65b9\u6cd5\uff1a<\/span><\/p>\n
\n
@Override<\/span><\/span><\/code>\npublic<\/span> int<\/span> hashCode<\/span>()<\/span> <\/span>{<\/span><\/code>\n    int<\/span> result = name != null<\/span> ? name.hashCode() : 0<\/span>;<\/span><\/code>\n    result = 31<\/span> * result + age;<\/span><\/code>\n    return<\/span> result;<\/span><\/code>\n}<\/span><\/code><\/pre>\n<\/section>\n
\u5f53equals()\u548chashCode()\u90fd\u57fa\u4e8ename\u548cage\u8fd9\u4e24\u4e2a\u5b57\u6bb5\u65f6\uff0c\u7b26\u5408\u7ea6\u5b9a\uff0c\u53ef\u4ee5\u786e\u4fdd\u96c6\u5408\u884c\u4e3a\u6b63\u786e\u3002\u73b0\u5728\uff0cHashSet\u5c06\u53ea\u4fdd\u5b58\u4e00\u4e2aPerson\u5143\u7d20\uff0c\u56e0\u4e3a\u4e24\u4e2aPerson\u5b9e\u4f8b\u867d\u7136\u662f\u4e0d\u540c\u7684\u5bf9\u8c61\uff0c\u4f46\u5b83\u4eec\u662f\"\u76f8\u7b49\"\u7684\uff0c\u5e76\u4e14\u5177\u6709\u76f8\u540c\u7684\u54c8\u5e0c\u7801\u3002<\/span><\/p>\n
\u603b\u7ed3<\/span><\/strong>\uff1a\u91cd\u5199\u8fd9\u4e24\u4e2a\u65b9\u6cd5\u7684\u5173\u952e\u5728\u4e8e\u7ef4\u62a4\u5bf9\u8c61\u7684\u4e00\u81f4\u6027\uff0c\u4f7f\u5176\u5728\u96c6\u5408\u4e2d\u8868\u73b0\u5f97\u7b26\u5408\u9884\u671f\u3002\u5426\u5219\uff0c\u4f1a\u5bfc\u81f4\u6570\u636e\u7ed3\u6784\u4e2d\u7684\u5143\u7d20\u67e5\u627e\u3001\u63d2\u5165\u3001\u5220\u9664\u7b49\u64cd\u4f5c\u51fa\u73b0\u5f02\u5e38\u884c\u4e3a\u3002<\/span><\/span><\/p>\n
\n
\u672c\u7bc7\u6587\u7ae0\u6765\u6e90\u4e8e\u5fae\u4fe1\u516c\u4f17\u53f7: \u4e92\u8054\u7f51\u9762\u8bd5\u5c0f\u5e2e\u624b<\/p><\/blockquote>\n<\/div>\n","raw":"","protected":false},"excerpt":{"rendered":"
\u5728 Java \u4e2d\uff0cequals()\u548c hashCode()\u65b9\u6cd5\u9700\u8981\u540c\u65f6\u91cd\u5199\u7684\u539f\u56e0\u6709\u4ee5\u4e0b\u51e0\u4e2a\uff1a 1. \u786e\u4fdd\u5bf9\u8c61\u6bd4\u8f83\u7684\u4e00\u81f4\u6027 \u5f53\u91cd\u5199  …<\/p>\n","protected":false},"author":1,"featured_media":3975,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[30],"tags":[],"class_list":["post-3978","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-30"],"post_thumbnail_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211-150x150.jpeg","content_first_image":null,"post_medium_image_300":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211-300x128.jpeg","post_thumbnail_image_624":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211.jpeg","post_frist_image":null,"post_medium_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211-300x128.jpeg","post_large_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211.jpeg","post_full_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2024\/05\/20240524144225211.jpeg","post_all_images":[],"videoAdId":"","listAd":"0","listAdId":"","listAdEvery":6,"total_comments":0,"category_name":"\u9762\u8bd5","post_date":"2024-05-17","like_count":"0","praiseWord":"\u9f13\u52b1","copyright_state":"","excitationAd":"0","rewardedVideoAdId":"","detailAdId":"","detailAd":"0","enterpriseMinapp":"0","audios":[],"postImageUrl":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230519082947553.jpg","avatarurls":[],"related_posts":null,"pageviews":288,"next_post_id":4751,"next_post_title":"\u7f8e\u56e2\u963f\u91cc\u9762\u8bd5\u8fde\u95ee\uff1aRedis\u4e0eMySQL\u53cc\u5199\u4e00\u81f4\u6027\u5982\u4f55\u5b9e\u73b0\uff1f","previous_post_id":3966,"previous_post_title":"\u9762\u8bd5\u5b98\uff1aConcurrentHashMap\u4e2d\u7684size()\u65b9\u6cd5\u5982\u4f55\u5de5\u4f5c\uff1f\u5b83\u7684\u7ed3\u679c\u662f\u5426\u603b\u662f\u51c6\u786e\u7684\uff1f","_links":{"self":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/3978","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/comments?post=3978"}],"version-history":[{"count":2,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/3978\/revisions"}],"predecessor-version":[{"id":6480,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/3978\/revisions\/6480"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media\/3975"}],"wp:attachment":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media?parent=3978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/categories?post=3978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/tags?post=3978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}