{"id":1203,"date":"2022-10-26T23:04:25","date_gmt":"2022-10-26T15:04:25","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1203"},"modified":"2022-11-27T12:39:48","modified_gmt":"2022-11-27T04:39:48","slug":"%e9%9b%86%e5%90%88-set%e6%8e%a5%e5%8f%a3%e5%ae%9e%e7%8e%b0%e7%b1%bb%e7%9a%84%e5%af%b9%e6%af%94%e3%80%81set%e7%9a%84%e6%97%a0%e5%ba%8f%e6%80%a7%e4%b8%8e%e4%b8%8d%e5%8f%af%e9%87%8d%e5%a4%8d%e6%80%a7","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1203","title":{"rendered":"\u96c6\u5408-Set\u63a5\u53e3\u5b9e\u73b0\u7c7b\u7684\u5bf9\u6bd4\u3001Set\u7684\u65e0\u5e8f\u6027\u4e0e\u4e0d\u53ef\u91cd\u590d\u6027\u7684\u7406\u89e3\u3001HashSet\u4e2d\u5143\u7d20\u7684\u6dfb\u52a0\u8fc7\u7a0b\u3001\u5173\u4e8ehashCode()\u548cequals()\u7684\u91cd\u5199\u3001LinkedHashSet\u7684\u4f7f\u7528"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P535;\r\n\r\nimport org.junit.jupiter.api.Test;\r\n\r\nimport java.util.HashSet;\r\nimport java.util.Iterator;\r\nimport java.util.LinkedHashSet;\r\nimport java.util.Set;\r\n\r\n\/**\r\n * 1. Set\u63a5\u53e3\u7684\u6846\u67b6\uff1a\r\n *\r\n *      |----Collection\u63a5\u53e3\uff1a\u5355\u5217\u96c6\u5408\uff0c\u7528\u6765\u5b58\u50a8\u4e00\u4e2a\u4e00\u4e2a\u7684\u5bf9\u8c61\r\n *          |----Set\u63a5\u53e3\uff1a\u5b58\u50a8\u65e0\u5e8f\u7684\u3001\u4e0d\u53ef\u91cd\u590d\u7684\u6570\u636e  -->\u9ad8\u4e2d\u8bb2\u7684\"\u96c6\u5408\"\r\n *                  |----HashSet\uff1a\u4f5c\u4e3aSet\u63a5\u53e3\u7684\u4e3b\u8981\u5b9e\u73b0\u7c7b\uff1b\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\uff1b\u53ef\u4ee5\u5b58\u50a8null\u503c\r\n *                      |----LinkedHashSet\uff1a\u4f5c\u4e3aHashSet\u7684\u5b50\u7c7b\uff1b\u904d\u5386\u5176\u5185\u90e8\u6570\u636e\u65f6\uff0c\u53ef\u4ee5\u6309\u7167\u6dfb\u52a0\u7684\u987a\u5e8f\u904d\u5386\r\n *                                          \u5bf9\u4e8e\u9891\u7e41\u7684\u904d\u5386\u64cd\u4f5c\uff0cLinkedHashSet\u6548\u7387\u9ad8\u4e8eHashSet\r\n *                  |----TreeSet\uff1a\u53ef\u4ee5\u6309\u7167\u6dfb\u52a0\u5bf9\u8c61\u7684\u6307\u5b9a\u5c5e\u6027\uff0c\u8fdb\u884c\u6392\u5e8f\u3002\r\n *\r\n * 1. Set\u63a5\u53e3\u4e2d\u6ca1\u6709\u989d\u5916\u5b9a\u4e49\u65b0\u7684\u65b9\u6cd5\uff0c\u4f7f\u7528\u7684\u90fd\u662fCollection\u4e2d\u58f0\u660e\u8fc7\u7684\u65b9\u6cd5\u3002\r\n *\r\n * 2.\u8981\u6c42\uff1a\u5411Set\u4e2d\u6dfb\u52a0\u7684\u6570\u636e\uff0c\u5176\u6240\u5728\u7684\u7c7b\u4e00\u5b9a\u8981\u91cd\u5199hashCode()\u548cequals()\r\n *   \u8981\u6c42\uff1a\u91cd\u5199\u7684hashCode()\u548cequals()\u5c3d\u53ef\u80fd\u4fdd\u6301\u4e00\u81f4\u6027\uff1a\u76f8\u7b49\u7684\u5bf9\u8c61\u5fc5\u987b\u5177\u6709\u76f8\u7b49\u7684\u6563\u5217\u7801\r\n *      \u91cd\u5199\u4e24\u4e2a\u65b9\u6cd5\u7684\u5c0f\u6280\u5de7\uff1a\u5bf9\u8c61\u4e2d\u7528\u4f5c equals() \u65b9\u6cd5\u6bd4\u8f83\u7684Field\uff0c\u90fd\u5e94\u8be5\u7528\u6765\u8ba1\u7b97 hashCode \u503c\u3002\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-26 \u4e0b\u5348 7:32\r\n *\/\r\npublic class SetTest {\r\n\r\n    \/*\r\n    Set\uff1a\u5b58\u50a8\u65e0\u5e8f\u7684\u3001\u4e0d\u53ef\u91cd\u590d\u7684\u6570\u636e\r\n    \u4ee5HashSet\u4e3a\u4f8b\u8bf4\u660e\uff1b\r\n    1. \u65e0\u5e8f\u6027\uff1a\u4e0d\u7b49\u4e8e\u968f\u673a\u6027\u3002\u5b58\u50a8\u7684\u6570\u636e\u5728\u5e95\u5c42\u6570\u7ec4\u4e2d\u5e76\u975e\u6309\u7167\u6570\u7ec4\u7d22\u5f15\u7684\u987a\u5e8f\u6dfb\u52a0\u3002\u800c\u662f\u6839\u636e\u6570\u636e\u7684\u54c8\u5e0c\u503c\u51b3\u5b9a\u7684\u3002\r\n\r\n    2. \u4e0d\u53ef\u91cd\u590d\u6027\uff1a\u4fdd\u8bc1\u6dfb\u52a0\u7684\u5143\u7d20\u6309\u7167equals()\u5224\u65ad\u65f6\uff0c\u4e0d\u80fd\u8fd4\u56detrue.\u5373\uff1a\u76f8\u540c\u7684\u5143\u7d20\u53ea\u80fd\u6dfb\u52a0\u4e00\u4e2a\u3002\r\n\r\n    \u4e8c\u3001\u6dfb\u52a0\u5143\u7d20\u7684\u8fc7\u7a0b\uff1a\u4ee5HashSet\u4e3a\u4f8b\uff1a\r\n        \u6211\u4eec\u5411HashSet\u4e2d\u6dfb\u52a0\u5143\u7d20a,\u9996\u5148\u8c03\u7528\u5143\u7d20a\u6240\u5728\u7c7b\u7684hashCode()\u65b9\u6cd5\uff0c\u8ba1\u7b97\u5143\u7d20a\u7684\u54c8\u5e0c\u503c\uff0c\r\n        \u6b64\u54c8\u5e0c\u503c\u63a5\u7740\u901a\u8fc7\u67d0\u79cd\u7b97\u6cd5\u8ba1\u7b97\u51fa\u5728HashSet\u5e95\u5c42\u6570\u7ec4\u4e2d\u7684\u5b58\u653e\u4f4d\u7f6e\uff08\u5373\u4e3a\uff1a\u7d22\u5f15\u4f4d\u7f6e\uff09,\u5224\u65ad\r\n        \u6570\u7ec4\u6b64\u4f4d\u7f6e\u4e0a\u662f\u5426\u5df2\u7ecf\u6709\u5143\u7d20\uff1a\r\n            \u5982\u679c\u6b64\u4f4d\u7f6e\u4e0a\u6ca1\u6709\u5176\u4ed6\u5143\u7d20\uff0c\u5219\u5143\u7d20a\u6dfb\u52a0\u6210\u529f\u3002--->\u60c5\u51b51\r\n            \u5982\u679c\u6b64\u4f4d\u7f6e\u4e0a\u6709\u5176\u4ed6\u5143\u7d20b\uff08\u6216\u4ee5\u94fe\u8868\u5f62\u5f0f\u5b58\u5728\u7684\u591a\u4e2a\u5143\u7d20\uff09\uff0c\u5219\u6bd4\u8f83\u5143\u7d20a\u4e0e\u5143\u7d20b\u7684hash\u503c\uff1a\r\n                \u5982\u679chash\u503c\u4e0d\u76f8\u540c\uff0c\u5219\u5143\u7d20a\u6dfb\u52a0\u6210\u529f\u3002--->\u60c5\u51b52\r\n                \u5982\u679chash\u503c\u76f8\u540c\uff0c\u8fdb\u800c\u9700\u8981\u8c03\u7528\u5143\u7d20a\u6240\u5728\u7c7b\u7684equals()\u65b9\u6cd5\uff1a\r\n                    equals()\u8fd4\u56detrue\uff0c\u5143\u7d20a\u6dfb\u52a0\u5931\u8d25\r\n                    equals()\u8fd4\u56defalse\uff0c\u5219\u5143\u7d20a\u6dfb\u52a0\u6210\u529f\u3002--->\u60c5\u51b53\r\n\r\n    \u5bf9\u4e8e\u6dfb\u52a0\u6210\u529f\u7684\u60c5\u51b52\u548c\u60c5\u51b53\u800c\u8a00\uff1a\u5143\u7d20a \u4e0e\u5df2\u7ecf\u5b58\u5728\u6307\u5b9a\u7d22\u5f15\u4f4d\u7f6e\u4e0a\u6570\u636e\u4ee5\u94fe\u8868\u7684\u65b9\u5f0f\u5b58\u50a8\u3002\r\n    jdk 7 : \u5143\u7d20a\u653e\u5230\u6570\u7ec4\u4e2d\uff0c\u6307\u5411\u539f\u6765\u7684\u5143\u7d20\u3002\r\n    jdk 8 : \u539f\u6765\u7684\u5143\u7d20\u5728\u6570\u7ec4\u4e2d\uff0c\u6307\u5411\u5143\u7d20a\r\n    \u603b\u7ed3\uff1a\u4e03\u4e0a\u516b\u4e0b\r\n\r\n    HashSet\u5e95\u5c42\uff1a\u6570\u7ec4+\u94fe\u8868\u7684\u7ed3\u6784\u3002\r\n\r\n     *\/\r\n\r\n    @Test\r\n    public void test1(){\r\n        Set set = new HashSet();\r\n        set.add(456);\r\n        set.add(123);\r\n        set.add(123);\r\n        set.add(\"AA\");\r\n        set.add(\"CC\");\r\n        set.add(new User(\"Tom\",12));\r\n        set.add(new User(\"Tom\",12));\r\n        set.add(129);\r\n\r\n        Iterator iterator = set.iterator();\r\n        while (iterator.hasNext()){\r\n            System.out.println(iterator.next());\r\n        }\r\n    }\r\n\r\n    \/\/LinkedHashSet\u7684\u4f7f\u7528\r\n    \/\/LinkedHashSet\u4f5c\u4e3aHashSet\u7684\u5b50\u7c7b\uff0c\u5728\u6dfb\u52a0\u6570\u636e\u7684\u540c\u65f6\uff0c\u6bcf\u4e2a\u6570\u636e\u8fd8\u7ef4\u62a4\u4e86\u4e24\u4e2a\u5f15\u7528\uff0c\u8bb0\u5f55\u6b64\u6570\u636e\u524d\u4e00\u4e2a\r\n    \/\/\u6570\u636e\u548c\u540e\u4e00\u4e2a\u6570\u636e\u3002\r\n    \/\/\u4f18\u70b9\uff1a\u5bf9\u4e8e\u9891\u7e41\u7684\u904d\u5386\u64cd\u4f5c\uff0cLinkedHashSet\u6548\u7387\u9ad8\u4e8eHashSet\r\n    @Test\r\n    public void test2(){\r\n        Set set = new LinkedHashSet();\r\n        set.add(456);\r\n        set.add(123);\r\n        set.add(123);\r\n        set.add(\"AA\");\r\n        set.add(\"CC\");\r\n        set.add(new User(\"Tom\",12));\r\n        set.add(new User(\"Tom\",12));\r\n        set.add(129);\r\n\r\n        Iterator iterator = set.iterator();\r\n        while (iterator.hasNext()){\r\n            System.out.println(iterator.next());\r\n        }\r\n    }\r\n}\r\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P535;\r\n\r\n\/**\r\n * @author RichieZhang\r\n * @create 2022-10-26 \u4e0b\u5348 8:16\r\n *\/\r\npublic class User {\r\n\r\n    private String name;\r\n    private int age;\r\n\r\n    public User(){\r\n\r\n    }\r\n\r\n    public User(String name, int age) {\r\n        this.name = name;\r\n        this.age = age;\r\n    }\r\n\r\n    public String getName() {\r\n        return name;\r\n    }\r\n\r\n    public void setName(String name) {\r\n        this.name = name;\r\n    }\r\n\r\n    public int getAge() {\r\n        return age;\r\n    }\r\n\r\n    public void setAge(int age) {\r\n        this.age = age;\r\n    }\r\n\r\n    @Override\r\n    public String toString() {\r\n        return \"User{\" +\r\n                \"name='\" + name + '\\'' +\r\n                \", age=\" + age +\r\n                '}';\r\n    }\r\n\r\n    @Override\r\n    public boolean equals(Object o) {\r\n        System.out.println(\"User equals()....\");\r\n        if (this == o) return true;\r\n        if (o == null || getClass() != o.getClass()) return false;\r\n\r\n        User user = (User) o;\r\n\r\n        if (age != user.age) return false;\r\n        return name != null ? name.equals(user.name) : user.name == null;\r\n    }\r\n\r\n    @Override\r\n    public int hashCode() { \/\/return name.hashCode() + age;\r\n        int result = name != null ? name.hashCode() : 0;\r\n        result = 31 * result + age;\r\n        return result;\r\n    }\r\n}\r\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P535;\r\n\r\n\/**\r\n * @author RichieZhang\r\n * @create 2022-10-25 \u4e0b\u5348 9:48\r\n *\/\r\npublic class Person {\r\n\r\n    private String name;\r\n    private int age;\r\n\r\n    public Person() {\r\n    }\r\n\r\n    public Person(String name, int age) {\r\n        this.name = name;\r\n        this.age = age;\r\n    }\r\n\r\n    public String getName() {\r\n        return name;\r\n    }\r\n\r\n    public void setName(String name) {\r\n        this.name = name;\r\n    }\r\n\r\n    public int getAge() {\r\n        return age;\r\n    }\r\n\r\n    public void setAge(int age) {\r\n        this.age = age;\r\n    }\r\n\r\n    @Override\r\n    public String toString() {\r\n        return \"Person{\" +\r\n                \"name='\" + name + '\\'' +\r\n                \", age=\" + age +\r\n                '}';\r\n    }\r\n\r\n    @Override\r\n    public boolean equals(Object o) {\r\n        System.out.println(\"Person equals().....\");\r\n        if (this == o) return true;\r\n        if (o == null || getClass() != o.getClass()) return false;\r\n\r\n        Person person = (Person) o;\r\n\r\n        if (age != person.age) return false;\r\n        return name != null ? name.equals(person.name) : person.name == null;\r\n    }\r\n\r\n}\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[46],"class_list":["post-1203","post","type-post","status-publish","format-standard","hentry","category-java-code","tag-java"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1203"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1203"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1203\/revisions"}],"predecessor-version":[{"id":1204,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1203\/revisions\/1204"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}