{"id":2124,"date":"2020-08-18T15:48:17","date_gmt":"2020-08-18T07:48:17","guid":{"rendered":"http:\/\/127.0.0.2\/?p=2124"},"modified":"2020-08-20T13:56:52","modified_gmt":"2020-08-20T05:56:52","slug":"2020java%e6%95%99%e7%a8%8b%ef%bc%9aobject%e7%b1%bb","status":"publish","type":"post","link":"https:\/\/www.9713job.com\/?p=2124","title":{"rendered":"2020java\u6559\u7a0b\uff1aObject\u7c7b"},"content":{"rendered":"

Object\u7c7b<\/h3>\n

Object\u7c7b
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\n\u4efb\u4f55\u7c7b\uff0c\u5982\u6ca1\u6709\u4e66\u5199extends\u663e\u793a\u7ee7\u627f\u67d0\u4e2a\u7c7b\uff0c\u90fd\u9ed8\u8ba4\u76f4\u63a5\u7ee7\u627fObject\u7c7b\uff0c\u5426\u5219\u4e3a\u95f4\u63a5\u7ee7\u627f\u3002
\nObject\u7c7b\u4e2d\u6240\u5b9a\u4e49\u7684\u65b9\u6cd5\uff0c\u662f\u6240\u6709\u5bf9\u8c61\u90fd\u5177\u5907\u7684\u65b9\u6cd5
\nObject\u7c7b\u578b\u53ef\u4ee5\u5b58\u50a8\u4efb\u4f55\u5bf9\u8c61
\n\u4f5c\u4e3a\u53c2\u6570\uff0c\u53ef\u63a5\u53d7\u4efb\u4f55\u53c2\u6570
\n\u4f5c\u4e3a\u8fd4\u56de\u503c\uff0c\u53ef\u8fd4\u56de\u4efb\u4f55\u5bf9\u8c61<\/p>\n

getClass()\u65b9\u6cd5
\npublic final Class<?> getClass(){}
\n\u8fd4\u56de\u5f15\u7528\u4e2d\u5b58\u50a8\u7684\u5b9e\u9645\u5bf9\u8c61\u7c7b\u578b<\/p>\n

public class demos{\r\n    public static void main(String[] args) {\r\n        Student s=new Student();\r\n        System.out.println(s.getClass());\r\n    }\r\n}\r\nclass Student{}<\/pre>\n
\u5e94\u7528\uff1a\u901a\u5e38\u7528\u4e8e\u5224\u65ad\u4e24\u4e2a\u5f15\u7528\u4e2d\u5b9e\u9645\u5b58\u50a8\u5bf9\u8c61\u7c7b\u578b\u662f\u5426\u4e00\u81f4\u3002<\/p>\n
\n
hashCode()\u65b9\u6cd5<\/p>\n
public int hashCode(){}
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\n\u54c8\u5e0c\u7b97\u6cd5\u6839\u636e\u5bf9\u8c61\u7684\u5730\u5740\u6216\u5b57\u7b26\u4e32\u6216\u6570\u5b57\u8ba1\u7b97\u51fa\u6765\u7684int\u7c7b\u578b\u7684\u6570\u503c
\n\u54c8\u5e0c\u7801\u4e0d\u552f\u4e00\uff0c\u53ef\u4fdd\u8bc1\u76f8\u540c\u5bf9\u8c61\u8fd4\u56de\u76f8\u540c\u54c8\u5e0c\u7801\uff0c\u5c3d\u91cf\u4fdd\u8bc1\u4e0d\u540c\u5bf9\u8c61\u8fd4\u56de\u4e0d\u540c\u54c8\u5e0c\u7801<\/p>\n
public class demos{\r\n    public static void main(String[] args) {\r\n        for(int i=0;i<5;i++){\r\n            Object o=new Object();\r\n            System.out.println(o.hashCode());\r\n        }\r\n    }\r\n}<\/pre>\n
\n
toString()\u65b9\u6cd5
\npublic String toString(){}
\n\u8fd4\u56de\u8be5\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\u8868\u793a(\u8868\u73b0\u5f62\u5f0f)
\n\u53ef\u4ee5\u6839\u636e\u7a0b\u5e8f\u9700\u6c42\u8986\u76d6\u8be5\u65b9\u6cd5\uff0c\u5982\uff1a\u5c55\u793a\u5bf9\u8c61\u5404\u4e2a\u5c5e\u6027\u503c\u3002<\/p>\n
public class demos{\r\n    public static void main(String[] args) {\r\n        for(int i=0;i<5;i++){\r\n            Object o=new Object();\r\n            System.out.println(o.toString());\r\n        }\r\n    }\r\n}<\/pre>\n
\n
equals()\u65b9\u6cd5<\/p>\n
public boolean equals(Object obj){}
\n\u9ed8\u8ba4\u5b9e\u73b0(this==obj)\uff0c\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u5730\u5740\u662f\u5426\u76f8\u540c<\/p>\n
public class demos{\r\n    public static void main(String[] args) {\r\n        Object o1=new Object();\r\n        Object o2=new Object();\r\n        System.out.println(o1.equals(o2));\r\n        System.out.println(o1 == o2);\r\n    }\r\n}<\/pre>\n
\u53ef\u8fdb\u884c\u8986\u76d6\uff0c\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u7684\u5185\u5bb9\u662f\u5426\u76f8\u540c
\nequals()\u65b9\u6cd5\u8986\u76d6\u6b65\u9aa4<\/p>\n
\u6bd4\u8f83\u4e24\u4e2a\u5f15\u7528\u662f\u5426\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61
\n\u5224\u65adobj\u662f\u5426\u4e3anull
\n\u5224\u65ad\u4e24\u4e2a\u5f15\u7528\u6307\u5411\u7684\u5b9e\u9645\u5bf9\u8c61\u7c7b\u578b\u662f\u5426\u4e00\u81f4
\n\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362
\n\u4f9d\u6b21\u6bd4\u8f83\u5404\u4e2a\u5c5e\u6027\u503c\u662f\u5426\u76f8\u540c<\/p>\n
public class demos{\r\n    public static void main(String[] args) {\r\n        Student s1=new Student(\"\u5f20\u4e09\",22,\"\u7537\",99);\r\n        Student s2=new Student(new String(\"\u5f20\u4e09\"),22,\"\u7537\",99);\r\n        System.out.println(s1 == s2);\r\n        System.out.println(s1.equals(s2));\r\n    }\r\n}\r\nclass Student{\r\n    String name;\r\n    int age;\r\n    String sex;\r\n    double score;\r\n    public Student(String name, int age, String sex, double score) {\r\n        this.name = name;\r\n        this.age = age;\r\n        this.sex = sex;\r\n        this.score = score;\r\n    }\r\n    @Override\r\n    public boolean equals(Object o){\r\n        if(this==o){\r\n            return true;\r\n        }\r\n        if(o==null){\r\n            return false;\r\n        }\r\n        if(this.getClass()!=o.getClass()){\r\n            return false;\r\n        }\r\n        Student s=(Student)o;\r\n        if(this.name.equals(s.name)&&this.age==s.age&&this.sex.equals(s.sex)&&this.score==s.score)return true;\r\n        return false;\r\n    }\r\n}<\/pre>\n
\n
finalize()\u65b9\u6cd5<\/p>\n
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public class demos{\r\n    public static void main(String[] args) {\r\n        MyClass mc=new MyClass();\r\n        mc=null;\r\n        System.gc();\r\n    }\r\n}\r\nclass XXX{\r\n    public static MyClass mc;\r\n}\r\nclass MyClass{\r\n    @Override\r\n    protected void finalize() throws Throwable {\r\n        XXX.mc=this;\r\n        System.out.println(\"MyClass finalize\");\r\n        super.finalize();\r\n    }\r\n}<\/pre>\n
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\n\u624b\u52a8\u56de\u6536\u673a\u5236\uff1a\u4f7f\u7528System.gc();\u901a\u77e5JVM\u6267\u884c\u5783\u573e\u56de\u6536<\/p>\n","protected":false},"excerpt":{"rendered":"
Object\u7c7b Object\u7c7b \u8d85\u7c7b\u3001\u57fa\u7c7b\u3001\u6240\u6709\u7c7b\u7684\u76f4\u63a5\u6216\u95f4\u63a5\u7236\u7c7b\uff0c\u4f4d\u4e8e\u7ee7\u627f\u6811\u7684\u6700\u9876\u5c42 \u4efb\u4f55\u7c7b\uff0c\u5982\u6ca1\u6709\u4e66\u5199ex […]<\/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-2124","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2124","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=2124"}],"version-history":[{"count":7,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2124\/revisions"}],"predecessor-version":[{"id":2143,"href":"https:\/\/www.9713job.com\/index.php?rest_route=\/wp\/v2\/posts\/2124\/revisions\/2143"}],"wp:attachment":[{"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.9713job.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}