{"id":159793,"date":"2020-09-22T02:53:32","date_gmt":"2020-09-21T18:53:32","guid":{"rendered":"http:\/\/4563.org\/?p=159793"},"modified":"2020-09-22T02:53:32","modified_gmt":"2020-09-21T18:53:32","slug":"%e8%af%b7%e9%97%ae-java-%e4%b8%ad%e7%9a%84%e7%bc%96%e8%af%91%e6%9c%9f%e5%8f%af%e7%9f%a5%ef%bc%8c%e8%bf%90%e8%a1%8c%e6%9c%9f%e4%b8%8d%e5%8f%98%e7%9a%84%e7%88%b6%e7%b1%bb%e6%96%b9","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=159793","title":{"rendered":"\u8bf7\u95ee Java \u4e2d\u7684\u201c\u7f16\u8bd1\u671f\u53ef\u77e5\uff0c\u8fd0\u884c\u671f\u4e0d\u53d8\u201d\u7684\u7236\u7c7b\u65b9\u6cd5\u662f\u4ec0\u4e48\uff1f"},"content":{"rendered":"
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\u8bf7\u95ee Java \u4e2d\u7684\u201c\u7f16\u8bd1\u671f\u53ef\u77e5\uff0c\u8fd0\u884c\u671f\u4e0d\u53d8\u201d\u7684\u7236\u7c7b\u65b9\u6cd5\u662f\u4ec0\u4e48\uff1f <\/h1>\n

<\/p>\n

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\u8cc7\u6df1\u5927\u4f6c : Newyorkcity <\/span> <\/i> 4<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n
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\u65b9\u6cd5\u5728\u7a0b\u5e8f\u771f\u6b63\u8fd0\u884c\u4e4b\u524d\u5c31\u6709\u4e00\u4e2a\u53ef\u786e\u5b9a\u7684\u8c03\u7528\u7248\u672c\uff0c\u5e76\u4e14\u8fd9\u4e2a\u65b9\u6cd5\u7684\u8c03\u7528\u7248\u672c\u5728\u8fd0\u884c\u671f\u662f\u4e0d\u53ef\u6539\u53d8\u7684\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u8c03\u7528\u76ee\u6807\u5728\u7a0b\u5e8f\u4ee3\u7801\u5199\u597d\u3001\u7f16\u8bd1\u5668\u8fdb\u884c\u7f16\u8bd1\u90a3\u4e00\u523b\u5c31\u5df2\u7ecf\u786e\u5b9a\u4e0b\u6765\u3002\u8fd9\u7c7b\u65b9\u6cd5\u7684\u8c03\u7528\u88ab\u79f0\u4e3a\u89e3\u6790\uff08 Resolution \uff09\u3002<\/p>\n<\/blockquote>\n

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\u53ea\u8981\u80fd\u88ab invokestatic \u548c invokespecial \u6307\u4ee4\u8c03\u7528\u7684\u65b9\u6cd5\uff0c\u90fd\u53ef\u4ee5\u5728\u89e3\u6790\u9636\u6bb5\u4e2d\u786e\u5b9a\u552f\u4e00\u7684\u8c03\u7528\u7248\u672c\uff0cJava \u8bed\u8a00\u91cc\u7b26\u5408\u8fd9\u4e2a\u6761\u4ef6\u7684\u65b9\u6cd5\u5171\u6709\u9759\u6001\u65b9\u6cd5\u3001\u79c1\u6709\u65b9\u6cd5\u3001\u5b9e\u4f8b\u6784\u9020\u5668\u3001\u7236\u7c7b\u65b9\u6cd5 4 \u79cd\uff0c\u518d\u52a0\u4e0a\u88ab final \u4fee\u9970\u7684\u65b9\u6cd5\uff08\u5c3d\u7ba1\u5b83\u4f7f\u7528 invokevirtual \u6307\u4ee4\u8c03\u7528\uff09\uff0c\u8fd9 5 \u79cd\u65b9\u6cd5\u8c03\u7528\u4f1a\u5728\u7c7b\u52a0\u8f7d\u7684\u65f6\u5019\u5c31\u53ef\u4ee5\u628a\u7b26\u53f7\u5f15\u7528\u89e3\u6790\u4e3a\u8be5\u65b9\u6cd5\u7684\u76f4\u63a5\u5f15\u7528\u3002\u8fd9\u4e9b\u65b9\u6cd5\u7edf\u79f0\u4e3a\u201c\u975e\u865a\u65b9\u6cd5\u201d\uff08 Non-Virtual Method \uff09\uff0c\u4e0e\u4e4b\u76f8\u53cd\uff0c\u5176\u4ed6\u65b9\u6cd5\u5c31\u88ab\u79f0\u4e3a\u201c\u865a\u65b9\u6cd5\u201d\uff08 Virtual Method \uff09\u3002<\/p>\n<\/blockquote>\n

\u4ee5\u4e0a\u5185\u5bb9\u51fa\u81ea\u5468\u5fd7\u660e\u5148\u751f\u7684\u300a\u6df1\u5165 JVM \uff08\u7b2c\u4e09\u7248\uff09\u300b\uff0c\u7ed3\u5408\u4e24\u6bb5\u5185\u5bb9\u53ef\u4ee5\u63a8\u8bba\u300e\u7236\u7c7b\u65b9\u6cd5\u662f\u5728\u7a0b\u5e8f\u4ee3\u7801\u5199\u597d\u3001\u7f16\u8bd1\u5668\u8fdb\u884c\u7f16\u8bd1\u90a3\u4e00\u523b\u5c31\u5df2\u7ecf\u786e\u5b9a\u4e0b\u6765\u7684\u300f\uff0c\u6211\u672c\u6765\u662f\u4ece\u5b57\u9762\u4e0a\u7406\u89e3\u5c31\u662f\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\uff0c\u4f46\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\u5e94\u8be5\u4e0d\u5177\u5907\u8fd9\u4e48\u8170\u690e\u76d8\u7a81\u51fa\u7684\u6027\u8d28\u5427\u3002\u3002\u3002<\/p>\n

\u8c22\u8c22<\/p>\n<\/p><\/div>\n

\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (4<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : codehz <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u6240\u6709\u80fd\u5199\u51fa\u6765\u7684\u65b9\u6cd5\u90fd\u662f\u7f16\u8bd1\u671f\u53ef\u77e5\uff0c\u8fd0\u884c\u671f\u4e0d\u53d8\u554a\uff0c\u9664\u975e\u4f60\u7528 asm \u5e93\u52a8\u6001\u521b\u5efa\uff0c\u4f46\u662f\u521b\u5efa\u7684\u8fc7\u7a0b\u903b\u8f91\u4e0a\u4e5f\u662f\u7f16\u8bd1\u671f\uff08
    \u4f60\u5728\u4e0d\u7ed5\u8fc7 jvm \u7684\u60c5\u51b5\u4e0b\u80fd\u5199\u51fa\u8fd0\u884c\u671f\u53ef\u53d8\u7684 java \u65b9\u6cd5\u5417\uff08 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : Newyorkcity <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @codehz <\/p>\n

    “`java
    import java.util.Random;<\/p>\n

    public class Main {
    public static void main(String[] args) {
    final Random random = new Random();
    Human person = random.nextBoolean() ? new Man() : new Woman();
    person.say();
    }<\/p>\n

    static abstract class Human {
    abstract void say();
    }<\/p>\n

    static class Man extends Human {
    @Override
    void say() {
    System.out.println(“I am male.”);
    }
    }<\/p>\n

    static class Woman extends Human {
    @Override
    void say() {
    System.out.println(“I am female”);
    }
    }
    }
    “` <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : codehz <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @Newyorkcity \u54e6\uff0c\u6211\u7406\u89e3\u9519\u4e86\uff0c\u770b\u9898\u76ee\u6211\u4ee5\u4e3a\u662f\u7c7b\u7684\u95ee\u9898 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : geelaw <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u7236\u7c7b\u65b9\u6cd5\u662f\u6307\u7528 super \u8c03\u7528\u7684\u57fa\u7c7b\u4e2d\u65b9\u6cd5\uff08\u7684\u7248\u672c\uff09\u3002<\/p>\n

    \u4f8b\u5982
    class B { public void Foo() { } }
    class D extends B { @Override public void Foo() { super.Foo(); } }
    \u8fd9\u91cc\u9762 super.Foo \u8c03\u7528 B.Foo \u662f\u7f16\u8bd1\u65f6\u51b3\u5b9a\u7684\u3002 <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n","protected":false},"excerpt":{"rendered":"

    \u8bf7\u95ee Java \u4e2d\u7684\u201c\u7f16\u8bd1\u671f\u53ef\u77e5\uff0c…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/159793"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=159793"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/159793\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=159793"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=159793"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=159793"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}